G2Cdb::Gene report

Gene id
G00001834
Gene symbol
NEFH (HGNC)
Species
Homo sapiens
Description
neurofilament, heavy polypeptide
Orthologue
G00000585 (Mus musculus)

Databases (8)

Curated Gene
OTTHUMG00000030223 (Vega human gene)
Gene
ENSG00000100285 (Ensembl human gene)
4744 (Entrez Gene)
1026 (G2Cdb plasticity & disease)
NEFH (GeneCards)
Literature
162230 (OMIM)
Marker Symbol
HGNC:7737 (HGNC)
Protein Sequence
P12036 (UniProt)

Literature (30)

Pubmed - other

  • A genome-wide association study of carotid atherosclerosis in HIV-infected men.

    Shrestha S, Irvin MR, Taylor KD, Wiener HW, Pajewski NM, Haritunians T, Delaney JA, Schambelan M, Polak JF, Arnett DK, Chen YD and Grunfeld C

    Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, 1665 University Blvd., Birmingham, AL 35294-0022, USA. sshresth@uab.edu

    Background: The role of host genetics in the development of subclinical atherosclerosis in the context of HIV-infected persons who are being treated with highly active antiretroviral therapy (HAART) is not well understood.

    Methods: The present genome-wide association study (GWAS) is based on 177 HIV-positive Caucasian males receiving HAART who participated in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM) Study. Common and internal carotid intima-media thicknesses (cIMT) measured by B-mode ultrasound were used as a subclinical measure of atherosclerosis. Single nucleotide polymorphisms (SNPs) were assayed using the Illumina HumanCNV370-quad beadchip. Copy Number Variants (CNV) were inferred using a hidden Markov Model (PennCNV). Regression analyses were used to assess the association of common and internal cIMT with individual SNPs and CNVs, adjusting for age, duration of antiretroviral treatment, and principal components to account for potential population stratification.

    Results: Two SNPs in tight linkage disequilibrium, rs2229116 (a missense, nonsynonymous polymorphism (IIe to Val)) and rs7177922, located in the ryanodine receptor (RYR3) gene on chromosome 15 were significantly associated with common cIMT (P-value < 1.61 x 10). The RYR gene family has been known to play a role in the etiology of cardiovascular disease and has been shown to be regulated by HIV TAT protein.

    Conclusion: These results suggest that in the context of HIV infection and HAART, a functional SNP in a biologically plausible candidate gene, RYR3, is associated with increased common carotid IMT, which is a surrogate for atherosclerosis.

    Funded by: NCRR NIH HHS: M01 RR000036, M01 RR000036-43, M01 RR000051, M01 RR000051-46, M01 RR000052, M01 RR000052-46, M01 RR000054, M01 RR000054-39, M01 RR000083, M01 RR000083-44, M01 RR000425, M01 RR000425-36, M01 RR000633-34, M01 RR000865, M01 RR000865-29, M01-RR00036, M01-RR00425, RR00051, RR00052, RR00054, RR00083, RR00636, RR00865, UL1 RR024131, UL1 RR024131-03; NHLBI NIH HHS: HL53359, HL74814, R01 HL053359-07, R01 HL074814, R01 HL074814-04; NIAID NIH HHS: K23 AI066943, K23 AI066943-05, K23 AI66943; NIDDK NIH HHS: DK063491, P30 DK063491, P30 DK063491-09, R01 DK033651, R01 DK057508, R01 DK057508-01, R01 DK57508

    AIDS (London, England) 2010;24;4;583-92

  • Comparative study of CSF neurofilaments in HTLV-1-associated myelopathy/tropical spastic paraparesis and other neurological disorders.

    Alberti C, Gonzalez J, Maldonado H, Medina F, Barriga A, García L, Kettlun A, Collados L, Puente J, Cartier L and Valenzuela M

    Bioquimica y Biologia Molecular, Universidad de Chile, Santiago, Chile .

    HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive CNS disease leading to corticospinal tract degeneration. Various degenerative diseases have increased neurofilament subunit concentration in cerebrospinal fluid (CSF), frequently showing hyperphosphorylation in neurofilaments. The aim of this study was to determine if there were elevated concentrations of neurofilament light subunit (NFL) and phosphorylated forms of neurofilament heavy subunit (PNFH) in HAM/TSP CSF. NF concentrations were compared with those of controls and patients with neurodegenerative diseases associated with other retroviruses (HIV-associated dementia, HAD) and a form of prion disease (familiar Creutzfeldt-Jakob, FCJD). Western blotting of CSF with antibodies against NFL showed two immunoreactive bands of 66 and 59 kDa, the latter probably corresponding to a partially degraded NFL form. The concentration of the 59-kDa form was not different in HAM/TSP compared with controls, but it was significantly increased in HAD and FCJD groups. ELISA assay for PNFH did not show differences among HAM/TSP, HAD, and control groups, while PNFH concentration was significantly elevated in FCJD. Our results show that CSF NFL and PNFH are not molecular markers of axonal damage for HAM/TSP probably due to the slow progression of this disease. NFL phosphorylation studies required previous immunoprecipitation from CSF for mass spectrometric analysis. This preliminary analysis indicated phosphorylation at S472 and at some other residues.

    AIDS research and human retroviruses 2009;25;8;803-9

  • Polymorphisms in genes involved in neurodevelopment may be associated with altered brain morphology in schizophrenia: preliminary evidence.

    Gregório SP, Sallet PC, Do KA, Lin E, Gattaz WF and Dias-Neto E

    Laboratório de Neurociências (LIM-27), Departmento e Instituto de Psiquiatria, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.

    An abnormality in neurodevelopment is one of the most robust etiologic hypotheses in schizophrenia (SZ). There is also strong evidence that genetic factors may influence abnormal neurodevelopment in the disease. The present study evaluated in SZ patients, whose brain structural data had been obtained with magnetic resonance imaging (MRI), the possible association between structural brain measures, and 32 DNA polymorphisms, located in 30 genes related to neurogenesis and brain development. DNA was extracted from peripheral blood cells of 25 patients with schizophrenia, genotyping was performed using diverse procedures, and putative associations were evaluated by standard statistical methods (using the software Statistical Package for Social Sciences - SPSS) with a modified Bonferroni adjustment. For reelin (RELN), a protease that guides neurons in the developing brain and underlies neurotransmission and synaptic plasticity in adults, an association was found for a non-synonymous polymorphism (Val997Leu) with left and right ventricular enlargement. A putative association was also found between protocadherin 12 (PCDH12), a cell adhesion molecule involved in axonal guidance and synaptic specificity, and cortical folding (asymmetry coefficient of gyrification index). Although our results are preliminary, due to the small number of individuals analyzed, such an approach could reveal new candidate genes implicated in anomalous neurodevelopment in schizophrenia.

    Funded by: NCI NIH HHS: P30 CA016672

    Psychiatry research 2009;165;1-2;1-9

  • Pin1-dependent prolyl isomerization modulates the stress-induced phosphorylation of high molecular weight neurofilament protein.

    Rudrabhatla P, Zheng YL, Amin ND, Kesavapany S, Albers W and Pant HC

    Laboratory of Neurochemistry, NINDS, National Institutes of Health, Bethesda, Maryland 20892, USA.

    Aberrant phosphorylation of neuronal cytoskeletal proteins is a key pathological event in neurodegenerative disorders such as Alzheimer disease (AD) and amyotrophic lateral sclerosis, but the underlying mechanisms are still unclear. Previous studies have shown that Pin1, a peptidylprolyl cis/trans-isomerase, may be actively involved in the regulation of Tau hyperphosphorylation in AD. Here, we show that Pin1 modulates oxidative stress-induced NF-H phosphorylation. In an in vitro kinase assay, the addition of Pin1 substantially increased phosphorylation of NF-H KSP repeats by proline-directed kinases, Erk1/2, Cdk5/p35, and JNK3 in a concentration-dependent manner. In vivo, dominant-negative (DN) Pin1 and Pin1 small interfering RNA inhibited epidermal growth factor-induced NF-H phosphorylation. Because oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases, we studied the role of Pin1 in stressed cortical neurons and HEK293 cells. Both hydrogen peroxide (H(2)O(2)) and heat stresses induce phosphorylation of NF-H in transfected HEK293 cells and primary cortical cultures. Knockdown of Pin1 by transfected Pin1 short interference RNA and DN-Pin1 rescues the effect of stress-induced NF-H phosphorylation. The H(2)O(2) and heat shock induced perikaryal phospho-NF-H accumulations, and neuronal apoptosis was rescued by inhibition of Pin1 in cortical neurons. JNK3, a brain-specific JNK isoform, is activated under oxidative and heat stresses, and inhibition of Pin1 by Pin1 short interference RNA and DN-Pin1 inhibits this pathway. These results implicate Pin1 as a possible modulator of stress-induced NF-H phosphorylation as seen in neurodegenerative disorders like AD and amyotrophic lateral sclerosis. Thus, Pin1 may be a potential therapeutic target for these diseases.

    Funded by: Intramural NIH HHS

    The Journal of biological chemistry 2008;283;39;26737-47

  • Detection of phosphorylated NF-H in the cerebrospinal fluid and blood of aneurysmal subarachnoid hemorrhage patients.

    Lewis SB, Wolper RA, Miralia L, Yang C and Shaw G

    Department of Neurological Surgery, McKnight Brain Institute, University of Florida College of Medicine, Gainesville, Florida, USA.

    Blood and cerebrospinal fluid (CSF) of 30 Fisher grade 3 aneurysmal subarachnoid hemorrhage (ASAH) patients were analyzed for the presence of the phosphorylated axonal form of the major neurofilament subunit NF-H (pNF-H), a promising biomarker of axonal injury. Patient demographic data including development of vasospasm and outcome scores at 6 months after aneurysmal rupture (AR) were evaluated. Higher pNF-H blood levels in the first few days after AR were strongly predictive of a negative outcome. Blood pNF-H levels in most recovering patients showed a steady increase into the second week after AR, presumably reflecting axonal degeneration secondary to the original insult. Almost half of the patients studied showed sudden dramatic peaks of pNF-H protein release into CSF in the 3- to 14-day time period after AR, which must reflect profound, coordinated, and secondary loss of axons. Patients in whom vasospasm was detected had significantly more pNF-H in both blood and CSF compared with those in whom vasospasm was not detected. We conclude that the analysis of pNF-H levels in blood and CSF differentiates between patients with poor and favorable outcomes and also reveals several novel features of ASAH progression and recovery.

    Funded by: NCRR NIH HHS: M01 RR000082, MO1-RR00082

    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 2008;28;6;1261-71

  • Phosphorylated neurofilament heavy chain is a marker of neurodegeneration in Leber hereditary optic neuropathy (LHON).

    Guy J, Shaw G, Ross-Cisneros FN, Quiros P, Salomao SR, Berezovsky A, Carelli V, Feuer WJ and Sadun AA

    Bascom Palmer Eye Institute, McKnight Vision Research Center, Miami, FL 33136, USA. jguy@med.miami.edu

    Purpose: To determine the profile of neurodegeneration in Leber hereditary optic neuropathy (LHON).

    Methods: We quantitated serum levels of phosphorylated neurofilament heavy chain (pNF-H) in a Brazilian pedigree of 16 affected patients and 59 carriers with LHON, both molecularly characterized as harboring the G to A mutation at nucleotide 11,778 of the mitochondrial genome. The association of subject characteristics to pNF-H levels was studied with multiple regression; pNF-H data were square-root transformed to effect normality of distribution of residuals. Relationships between the square-root of pNF-H and age and sex were investigated within groups with Pearson correlation and the two-sample t-test. Linear regression was used to assess the difference between groups and to determine if the relationship of age was different between affected individuals and carriers. Results of plotting pNF-H levels by age suggested a nonlinear, quadratic association so age squared was used in the statistical analysis. ANCOVA was used to assess the influence of age and group on pNF-H levels.

    Results: In the carrier group, there was a significant correlation of square-root pNF-H (mean=0.24 ng/ml(2)) with age (r=0.30, p=0.022) and a stronger correlation with quadratic age (r=0.37, p=0.003). With a higher mean pNF-H (0.33 ng/ml(2)) for the affected group, correlations were of similar magnitude, although they were not statistically significant: age (r=0.22, p=0.42), quadratic age (r=0.22, p=0.45). There was no correlation between age and pNF-H levels (mean=0.34 ng/ml(2)) in the off-pedigree group: age (r=0.03, p=0.87), quadratic age (r=0.04, p=0.84). There was no difference between sexes and pNF-H levels in any of the groups (affected, p=0.65; carriers, p=0.19; off-pedigree, p=0.93).

    Conclusions: Elevated pNF-H released into the serum of some affected LHON patients may suggest that axonal degeneration occurs at some point after loss of visual function. Increases in pNF-H levels of carriers with increasing age, not seen in off-pedigree controls, may suggest subtle subclinical optic nerve degeneration.

    Funded by: NEI NIH HHS: 1R01EY017141-01A2, EY014801, EY018600-01, P30 EY014801, R01 EY017141, R24 EY018600

    Molecular vision 2008;14;2443-50

  • Inhibition of Pin1 reduces glutamate-induced perikaryal accumulation of phosphorylated neurofilament-H in neurons.

    Kesavapany S, Patel V, Zheng YL, Pareek TK, Bjelogrlic M, Albers W, Amin N, Jaffe H, Gutkind JS, Strong MJ, Grant P and Pant HC

    Cytoskeletal Protein Regulation Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA.

    Under normal conditions, the proline-directed serine/threonine residues of neurofilament tail-domain repeats are exclusively phosphorylated in axons. In pathological conditions such as amyotrophic lateral sclerosis (ALS), motor neurons contain abnormal perikaryal accumulations of phosphorylated neurofilament proteins. The precise mechanisms for this compartment-specific phosphorylation of neurofilaments are not completely understood. Although localization of kinases and phosphatases is certainly implicated, another possibility involves Pin1 modulation of phosphorylation of the proline-directed serine/threonine residues. Pin1, a prolyl isomerase, selectively binds to phosphorylated proline-directed serine/threonine residues in target proteins and isomerizes cis isomers to more stable trans configurations. In this study we show that Pin1 associates with phosphorylated neurofilament-H (p-NF-H) in neurons and is colocalized in ALS-affected spinal cord neuronal inclusions. To mimic the pathology of neurodegeneration, we studied glutamate-stressed neurons that displayed increased p-NF-H in perikaryal accumulations that colocalized with Pin1 and led to cell death. Both effects were reduced upon inhibition of Pin1 activity by the use of an inhibitor juglone and down-regulating Pin1 levels through the use of Pin1 small interfering RNA. Thus, isomerization of lys-ser-pro repeat residues that are abundant in NF-H tail domains by Pin1 can regulate NF-H phosphorylation, which suggests that Pin1 inhibition may be an attractive therapeutic target to reduce pathological accumulations of p-NF-H.

    Funded by: Intramural NIH HHS; NIMH NIH HHS: MH/NS 31862

    Molecular biology of the cell 2007;18;9;3645-55

  • CSF neurofilaments in frontotemporal dementia compared with early onset Alzheimer's disease and controls.

    Pijnenburg YA, Janssen JC, Schoonenboom NS, Petzold A, Mulder C, Stigbrand T, Norgren N, Heijst H, Hack CE, Scheltens P and Teunissen CE

    Department of Neurology, Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands, and Chelsea and Westminster, Brompton and Charing Cross Hospitals, London, UK. y.pijnenburg@vumc.nl

    Background: Frontotemporal dementia (FTD) is pathologically heterogeneous, sometimes revealing intraneuronal inclusions of neurofilaments. We therefore measured CSF neurofilament profiles in patients with FTD, patients with early onset Alzheimer's disease (EAD) and healthy control subjects to explore the discriminative potential of CSF neurofilaments compared with the existing CSF biomarkers amyloid-beta(1-42), tau and tau phosphorylated at threonine-181.

    Methods: CSF levels of light chain, heavy chain and hyperphosphorylated heavy chain neurofilaments (NfL, t-NfH and P-NfH) were compared between 17 subjects with FTD, 20 with EAD and 25 cognitively healthy controls.

    Results: A subgroup of FTD patients had remarkably high CSF levels of both NfL and NfH. The degree of NfH phosphorylation was increased in FTD compared to both other groups. The levels of CSF NfL were significantly higher in EAD compared to controls.

    Conclusion: Differences in CSF biomarker profiles might reflect differential involvement of neurofilaments and tau in FTD and EAD. The subgroup of FTD patients with high CSF neurofilament levels may have a different neuropathological substrate and future studies addressing this specific issue are needed.

    Dementia and geriatric cognitive disorders 2007;23;4;225-30

  • Mutations in neurofilament genes are not a significant primary cause of non-SOD1-mediated amyotrophic lateral sclerosis.

    Garcia ML, Singleton AB, Hernandez D, Ward CM, Evey C, Sapp PA, Hardy J, Brown RH and Cleveland DW

    Ludwig Institute for Cancer Research and Department of Neurosciences, University of California at San Diego, 9500 Gilman Drive, CMM-E/Room 3072, La Jolla, CA 92093-0670, USA.

    While 1 to 2% of amyotrophic lateral sclerosis (ALS) is caused by mutations in the SOD1 gene, the basis of the remaining instances of inherited disease is unknown. Neuropathology, mouse modeling, and human genetics have implicated neurofilaments in the pathogenesis of motor neuron diseases such as ALS and Charcot-Marie-Tooth disease (CMT). A systematic analysis of the coding region and intron-exon boundaries of all three neurofilament genes is now reported from DNA samples derived from more than 200 non-SOD1 linked familial and sporadic ALS patients, along with >400 non-disease control individuals. Rare variants within each of the three neurofilament subunits that are predicted to affect neurofilament assembly properties were identified at higher frequency in non-SOD1 mutant ALS samples. However, none could be unambiguously linked to dominantly inherited disease. Thus, mutations in neurofilaments are possible risk factors that may contribute to pathogenesis in ALS in conjunction with one or more additional genetic or environmental factors, but are not significant primary causes of ALS.

    Funded by: NINDS NIH HHS: R37 NS027036

    Neurobiology of disease 2006;21;1;102-9

  • The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

    Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Morrin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J and MGC Project Team

    The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline.

    Funded by: PHS HHS: N01-C0-12400

    Genome research 2004;14;10B;2121-7

  • Analysis of heavy neurofilament subunit gene polymorphism in Russian patients with sporadic motor neuron disease (MND).

    Skvortsova V, Shadrina M, Slominsky P, Levitsky G, Kondratieva E, Zherebtsova A, Levitskaya N, Alekhin A, Serdyuk A and Limborska S

    Department of Fundamental and Clinical Neurology, Russian State Medical University, Lenskay str.15, block 3, Moscow, Russia.

    Motor neuron disease (MND) results in the selective degeneration of motor neurons in the cerebral cortex, brain stem and spinal cord. The most common form of MND is amyotrophic lateral sclerosis (ALS). MND is complex and many genetic systems may be involved in the pathogenesis of this disease. Pathological and animal studies implicate neurofilament involvement in MND. The heavy subunit (NEFH) tail domain contains a repeated motif. In humans, there are two common variants: the 45 motif repeats long allele (L) and 44 motif repeats short allele (S). Previous studies have shown that the NEFH tail may be involved in the pathogenesis of MND. To investigate whether the L/S genotypes of the NEFH gene are associated with MND, we studied the frequency of L and S alleles in sporadic MND patients and a control population from Moscow. We observed a difference in SS genotype frequency between the control population and sporadic MND patients from Moscow. It was established that the SS genotype is sufficiently higher in sporadic MND patients. Moreover, we determined that patients with the SS genotype have the highest value of loss of the total clinical score. In summary, we conclude that the NEFH gene is involved in the pathogenesis of sporadic MND. The SS genotype represents a risk factor for the development and progression of sporadic MND in the Moscow population.

    European journal of human genetics : EJHG 2004;12;3;241-4

  • Co-purification and localization of Munc18-1 (p67) and Cdk5 with neuronal cytoskeletal proteins.

    Bhaskar K, Shareef MM, Sharma VM, Shetty AP, Ramamohan Y, Pant HC, Raju TR and Shetty KT

    Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India.

    Munc18-1 (p67, nSec1, rbSec1), a neuron-specific 67kDa protein was independently identified as a syntaxin-binding protein, and as a component that co-purifies with, and regulates the kinase activity of cyclin dependent kinase (Cdk5). Gene knockout studies have demonstrated a role for Munc18-1 in synaptic vesicle docking and neurotransmitter release. Mice lacking Munc18-1 gene were synaptically silent, but the gene deletion did not prevent normal brain assembly, including the formation of layered structures, fiber pathways and morphologically defined synapses. Previous study has shown that Munc18-1 facilitates Cdk5 mediated phosphorylation of KSPXK domains of the neuronal cytoskeletal elements, suggesting that Munc18-1 may function in the regulation of cytoskeletal dynamics. Present study demonstrates the co-purification and co-localization of Munc18 with cytoskeletal elements and forms first step towards understanding the role for Munc18-1 in cytoskeletal dynamics. Conversely, the cytoskeletal proteins and Cdk5 co-purifies with Munc18-1 in a Munc18-1 immuno-affinity chromatography, suggesting a strong protein-protein interaction. Findings from immunofluorescence studies in PC12 cells have shown co-localization of Munc18-1 and Cdk5 with neurofilaments and microtubules. Further, immunohistochemical and immuno-electron microscopic studies of rat olfactory bulb also demonstrated co-localization of Munc18-1 and Cdk5 with cytoskeletal elements. Thus, the biochemical evidence of strong interaction between Munc18-1 with cytoskeletal proteins and morphological evidence of their (Munc18 and cytoskeletal elements) identical sub-cellular localization is suggestive of the possible role for Munc18-1 in cytoskeletal dynamics.

    Neurochemistry international 2004;44;1;35-44

  • NF-M is an essential target for the myelin-directed "outside-in" signaling cascade that mediates radial axonal growth.

    Garcia ML, Lobsiger CS, Shah SB, Deerinck TJ, Crum J, Young D, Ward CM, Crawford TO, Gotow T, Uchiyama Y, Ellisman MH, Calcutt NA and Cleveland DW

    Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA 92093, USA.

    Neurofilaments are essential for acquisition of normal axonal calibers. Several lines of evidence have suggested that neurofilament-dependent structuring of axoplasm arises through an "outside-in" signaling cascade originating from myelinating cells. Implicated as targets in this cascade are the highly phosphorylated KSP domains of neurofilament subunits NF-H and NF-M. These are nearly stoichiometrically phosphorylated in myelinated internodes where radial axonal growth takes place, but not in the smaller, unmyelinated nodes. Gene replacement has now been used to produce mice expressing normal levels of the three neurofilament subunits, but which are deleted in the known phosphorylation sites within either NF-M or within both NF-M and NF-H. This has revealed that the tail domain of NF-M, with seven KSP motifs, is an essential target for the myelination-dependent outside-in signaling cascade that determines axonal caliber and conduction velocity of motor axons.

    Funded by: NCRR NIH HHS: P41 RR004050, P41 RR04050; NINDS NIH HHS: NS 27036, NS 38855, R01 NS027036, R37 NS027036

    The Journal of cell biology 2003;163;5;1011-20

  • [Association of homozygosity for short allele (S) of heavy neurofilament subunit gene with motor neuron disease and oxidative stress development].

    Skvortsova VI, Limborskaia SA, Slominskiĭ PA, Brusov OS, karakhan VB, Gerasimova MM, Levitskaia NI, Levitskiĭ GN, Shadrina MI, Kondrat'eva EA, Alekhin AV, Serdiuk AV and Botvinko TM

    We analyzed distribution of heavy neurofilament (NF-H) gene S/L-polymorphic variants in 51 patients with idiopathic motor neuron disease (MND) vs control group and in relation to superoxide dismutases (SODs) activity and thiobarbituric acid reactive substances (TBARS) level in cerebrospinal fluid (CSF), erythrocytes and blood serum. We found that individuals with homozygosity for NF-H gene short allele (S/S-genotype carriers) in MND group predominate significantly over those in control one (p < 0.001). We revealed significant increase of oxidative markers in CSF and blood serum in MDN patients vs controls (p < 0.05), but not in patients with spondylogenic myelopathy, conforming non-specific role of oxidative stress in MND pathogenesis. There were no differences between TBARS level in CSF and serum in relation to the rate of MND progression, suggesting that oxidative stress does not influence the MND course. We showed normal SOD-1 activity in erythrocytes and CSF of MND patients that argued for the absence of these antioxidant enzymes deficiency in MND without SOD-1 gene mutations. We found significant association between homozygosity for short allele (S) and increased TBARS level in CSF (p < 0.02). These findings specify the role of NF-H with lower molecular weight in MND pathogenesis and make expedient antioxidants administration to MND patients homozygous for S-allele of NF-H gene.

    Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova 2003;103;2;38-44

  • In vivo and in vitro phosphorylation at Ser-493 in the glutamate (E)-segment of neurofilament-H subunit by glycogen synthase kinase 3beta.

    Sasaki T, Taoka M, Ishiguro K, Uchida A, Saito T, Isobe T and Hisanaga S

    Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Minami-ohsawa, Hachiohji, Tokyo 192-0397, Japan. sasaki-takahiro@c.metro-u.ac.jp

    Neurofilament (NF), a major neuronal intermediate filament, is composed of three subunits, NF-L, NF-M, and NF-H. All three subunits contain a well conserved glutamate (E)-rich region called "E-segment" in the N terminus of the tail region. Although the E-segments of NF-L and NF-M are phosphorylated by casein kinases, it has not been observed in NF-H. Using mass spectrometric analysis, we identified phosphorylation of the E-segment of NF-H, prepared from rat spinal cords, at Ser-493 and Ser-501 in the Ser-Pro sequences. The E-segment kinase was isolated from rat brain extract using column chromatography and identified as glycogen synthase kinase (GSK) 3beta. GSK3beta was shown to phosphorylate at Ser-493 in vitro by phosphopeptide mapping and site-directed mutagenesis, and in vivo in HEK293 cells using the phospho-Ser-493 antibody, but did not phosphorylate Ser-501. GSK3beta preferred Ser-493 to the KSP-repeated sequences for phosphorylation sites in the NF-H tail domain. Moreover, Ser-493 was a better phosphorylation site for GSK3beta than other proline-directed protein kinases, Cdk5/p35 and ERK. GSK3beta in the spinal cord extract was associated with NF cytoskeletons. Taken together, we concluded that Ser-493 in the E-segment of NF-H is phosphorylated by GSK3beta in rat spinal cords.

    The Journal of biological chemistry 2002;277;39;36032-9

  • Phosphorylation state of the native high-molecular-weight neurofilament subunit protein from cervical spinal cord in sporadic amyotrophic lateral sclerosis.

    Strong MJ, Strong WL, Jaffe H, Traggert B, Sopper MM and Pant HC

    Neurodegeneration Research Group, The John P. Robarts Research Institute, London, Ontario, Canada. mstrong@julian.uwo.ca

    The intraneuronal aggregation of phosphorylated high-molecular-weight neurofilament protein (NFH) in spinal cord motor neurons is considered to be a key pathological marker of amyotrophic lateral sclerosis (ALS). In order to determine whether this observation is due to the aberrant or hyper-phosphorylation of NFH, we have purified and characterized NFH from the cervical spinal cords of ALS patients and controls. We observed no differences between ALS and normal controls in the physicochemical properties of NFH in Triton X-100 insoluble protein fractions, with respect to migration patterns on 2D-iso electrofocusing (IEF) gels, the rate of Escherichia coli alkaline phosphatase mediated dephosphorylation, or the rate of calpain-mediated proteolysis. The rate of calpain-mediated proteolysis was unaffected by either exhaustive NFH dephosphorylation or by the addition of calmodulin to the reaction. Phosphopeptides and the phosphorylated motifs characterized by liquid chromatography tandem mass spectroscopy (LC/MS/MS) analysis demonstrated that all the phosphorylated residues found in ALS NFH were also found to be phosphorylated in normal human NFH samples. Hence, we have observed no difference in the physicochemical properties of normal and ALS NFH extracted from cervical spinal cords, suggesting that the perikaryal aggregation of highly phosphorylated NF in ALS neurons reflects the aberrant somatotopic localization of normally phosphorylated NFH.

    Journal of neurochemistry 2001;76;5;1315-25

  • Deletions of the heavy neurofilament subunit tail in amyotrophic lateral sclerosis.

    Al-Chalabi A, Andersen PM, Nilsson P, Chioza B, Andersson JL, Russ C, Shaw CE, Powell JF and Leigh PN

    Departments of Neuroscience and Clinical Neurosciences, Institute of Psychiatry and King's College School of Medicine and Dentistry, London SE5 8AF, UK. ammar@iop.bpmf.ac.uk

    Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degeneration resulting in paralysis and death, usually within 3 years of onset. Pathological and animal studies implicate neurofilament involvement in ALS, but whether this is primary or secondary is not clear. The heavy neurofilament subunit (NFH) tail is composed of a repeating amino acid motif, usually X-lysine-serine-proline-Y-lysine (XKSPYK), where X is a single amino acid and Y is one to three amino acids. There are two common polymorphic variants of 44 or 45 repeats. The tail probably regulates axonal calibre, with interfilament spacing determined by phosphorylation of the KSP motifs. A previous study suggested an association between sporadic cases of ALS and NFH tail deletions, but two subsequent studies have found none. We have analysed samples from two different populations (UK 207, Scandinavia 323) with age-matched controls for each group (UK 219, Scandinavia 228) and have found four novel NFH tail deletions, each involving a whole motif. These were found in three patients with sporadic ALS and a family with autosomal dominant ALS, although another was also found in two young controls. In all cases motif deletions were only associated with disease when paired with the long NFH allele. The deletions all occurred within a small region of the NFH tail. This has allowed us to propose a structural organization of the tail as well as allowing observed deletions both from this study and previous reports to be organized into logical groups. These results strongly suggest that NFH motif deletions can be a primary event in ALS but that they are not common.

    Human molecular genetics 1999;8;2;157-64

  • Prediction of the coding sequences of unidentified human genes. XII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.

    Nagase T, Ishikawa K, Suyama M, Kikuno R, Hirosawa M, Miyajima N, Tanaka A, Kotani H, Nomura N and Ohara O

    Kazusa DNA Research Institute, Kisarazu, Chiba, Japan.

    In this paper, we report the sequences of 100 cDNA clones newly determined from a set of size-fractionated human brain cDNA libraries and predict the coding sequences of the corresponding genes, named KIAA0819 to KIAA0918. These cDNA clones were selected on the basis of their coding potentials of large proteins (50 kDa and more) by using in vitro transcription/translation assays. The sequence data showed that the average sizes of the inserts and corresponding open reading frames are 4.4 kb and 2.5 kb (831 amino acid residues), respectively. Homology and motif/domain searches against the public databases indicated that the predicted coding sequences of 83 genes were similar to those of known genes, 59% of which (49 genes) were categorized as coding for proteins functionally related to cell signaling/communication, cell structure/motility and nucleic acid management. The chromosomal locations and the expression profiles of all the genes were also examined. For 54 clones including brain-specific ones, the mRNA levels were further examined among 8 brain regions (amygdala, corpus callosum, cerebellum, caudate nucleus, hippocampus, substantia nigra, subthalamic nucleus, and thalamus), spinal cord, and fetal brain.

    DNA research : an international journal for rapid publication of reports on genes and genomes 1998;5;6;355-64

  • Novel insertion in the KSP region of the neurofilament heavy gene in amyotrophic lateral sclerosis (ALS).

    Tomkins J, Usher P, Slade JY, Ince PG, Curtis A, Bushby K and Shaw PJ

    Department of Neurology, University of Newcastle upon Tyne, Royal Victoria Infirmary, Medical School, UK.

    The abnormal assembly and accumulation of neurofilaments (NF) in the perikarya and proximal axons of motor neurones is a characteristic of ALS. Deletions in the KSP repeat region of the NF-H gene have previously been reported in seven patients with sporadic ALS. Here we report the identification of a novel 84 bp insertion in the NF-H gene. This leads to an extra four KSP repeat elements in a highly conserved repetitive region of the gene. Although neurofilament mutations are only associated with a very small proportion of ALS cases, this insertion provides further support of a role for neurofilaments in the pathogenesis of ALS.

    Funded by: Wellcome Trust

    Neuroreport 1998;9;17;3967-70

  • Mitogen-activated protein kinases (Erk1,2) phosphorylate Lys-Ser-Pro (KSP) repeats in neurofilament proteins NF-H and NF-M.

    Veeranna, Amin ND, Ahn NG, Jaffe H, Winters CA, Grant P and Pant HC

    Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.

    Mammalian neurofilament proteins, particularly midsized (NF-M) and heavy (NF-H) molecular weight neurofilament proteins, are highly phosphorylated in axons. Neurofilament function depends on the state of phosphorylation of the numerous serine/threonine residues in these proteins. Most phosphorylation occurs in the lys-ser-pro (KSP) repeats in the C-terminal tail domains of NF-H and NF-M. In our previous study, cyclin-dependent kinase 5 (cdk5) was shown to phosphorylate specifically the KSPXK repeats in rat NF-H. Because 80% of the repeats are of the KSPXXXK type, it was of interest to determine which kinase phosphorylates these motifs. Using a synthetic KSPXXXK peptide to screen for a specific kinase, we fractionated rat brain extracts by column chromatography and identified extracellular signal-regulated kinase (Erk2) activated by an upstream activator, the mitogen-activated protein kinase kinase MAPKK (MEK), by Western blot analysis, sequence identification, and inhibition by a specific MEK inhibitor (PD 98059). The fraction containing Erk2, as well as bacterially expressed Erk1 and Erk2, phosphorylated all types of KSP motifs in peptides (KSPXK, KSPXXK, KSPXXXK, and KSPXXXXK) derived from NF-M and NF-H. They also phosphorylated an expressed 24 KSPXXXK repeat NF-H polypeptide, an expressed NF-H as well as dephosphorylated native rat NF-H, and NF-M proteins with accompanying decreases in their respective electrophoretic mobilities. A comparative kinetic study of Erk2 and cdk5 phosphorylation of KSPXK and KSPXXXK peptides revealed that, in contrast to cdk5, which phosphorylated only the KSPXK peptide, Erk2 could phosphorylate both. The preferred substrate for Erk2 was KSPXXXK peptide. The MEK inhibitor PD 98059 also inhibited phosphorylation of NF-H, NF-M, and microtubule-associated protein (MAP) in primary rat hippocampal cells and caused a decrease in neurite outgrowth, suggesting that Erk1,2 may play an important role in neurite growth and branching. These data suggest that neuronal Erk1 and Erk2 are capable of phosphorylating serine residues in diverse KSP repeat motifs in NF-M and NF-H.

    The Journal of neuroscience : the official journal of the Society for Neuroscience 1998;18;11;4008-21

  • Heterodimeric associations between neuronal intermediate filament proteins.

    Athlan ES and Mushynski WE

    Department of Biochemistry, McGill University, 3655 Drummond Street, Montreal, Quebec H3G 1Y6, Canada.

    Formation of protein dimers involving alpha-internexin, peripherin, and the neurofilament (NF) proteins NFH, NFM, and NFL was investigated by partial renaturation of various combinations of individually purified subunits in buffered 2 M urea. Oligomers that were formed were resolved by "blue" native electrophoresis (Schägger, H., Cramer, W. A., and von Jagow, G. (1994) Anal. Biochem. 217, 220-230) modified to include urea in the polyacrylamide gels. Combining this method with Western blot analysis, disulfide cross-linking, and SDS-polyacrylamide gel electrophoresis in the second dimension showed that NFL readily forms significant amounts of heterodimer with NFH, NFM, alpha-internexin, or peripherin in the presence of 2 M urea. alpha-Internexin and peripherin also formed heterodimers with NFH or NFM under these conditions. The modified version of blue native gel electrophoresis described here may be useful in monitoring the impact of post-translational modifications and mutations on the dimerization of intermediate filament proteins.

    The Journal of biological chemistry 1997;272;49;31073-8

  • PKN associates and phosphorylates the head-rod domain of neurofilament protein.

    Mukai H, Toshimori M, Shibata H, Kitagawa M, Shimakawa M, Miyahara M, Sunakawa H and Ono Y

    Department of Biology, Faculty of Science, Kobe University, Japan.

    PKN is a fatty acid-activated serine/threonine kinase that has a catalytic domain highly homologous to that of protein kinase C in the carboxyl terminus and a unique regulatory region in the amino terminus. Recently, we reported that the small GTP-binding protein Rho binds to the amino-terminal region of PKN and activates PKN in a GTP-dependent manner, and we suggested that PKN is located on the downstream of Rho in the signal transduction pathway (Amano, M., Mukai, H., Ono, Y., Chihara, K., Matsui, T., Hamajima, Y., Okawa, K., Iwamatsu, A., and Kaibuchi, K. (1996) Science 271, 648-650; Watanabe, G., Saito, Y., Madaule, P., Ishizaki, T., Fujisawa, K., Morii, N., Mukai, H., Ono, Y. Kakizuka, A., and Narumiya, S. (1996) Science 271, 645-648). To identify other components of the PKN pathway such as substrates and regulatory proteins of PKN, the yeast two-hybrid strategy was employed. By this screening, a clone encoding the neurofilament L protein, a subunit of neuron-specific intermediate filament, was isolated. The amino-terminal regulatory region of PKN was shown to associate with the head-rod domains of other subunits of neurofilament (neurofilament proteins M and H) as well as neurofilament L protein in yeast cells. The direct binding between PKN and each subunit of neurofilament was confirmed by using the in vitro translated amino-terminal region of PKN and glutathione S-transferase fusion protein containing the head-rod domain of each subunit of neurofilament. PKN purified from rat testis phosphorylated each subunit of the native neurofilament purified from bovine spinal cord and the bacterially synthesized head-rod domain of each subunit of neurofilament. Polymerization of neurofilament L protein in vitro was inhibited by phosphorylation of neurofilament L protein by PKN. The identification and characterization of the novel interaction with PKN may contribute toward the elucidation of mechanisms regulating the function of neurofilament.

    The Journal of biological chemistry 1996;271;16;9816-22

  • Variants of the heavy neurofilament subunit are associated with the development of amyotrophic lateral sclerosis.

    Figlewicz DA, Krizus A, Martinoli MG, Meininger V, Dib M, Rouleau GA and Julien JP

    Centre for Research in Neuroscience, McGill University, Montreal, Quebec, Canada.

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily affecting motor neurons. The etiology of the majority of cases remains unknown. Recent findings from several laboratories suggest a role for neurofilaments in the development of motor neuron disorders. The C-terminal region of the human neurofilament heavy subunit (NEFH) contains a unique functional domain consisting of 43 repeat motifs of the amino acids Lys-Ser-Pro (KSP). This C-terminal region of NEFH forms the sidearm projections which cross-link the neurofilaments. Previously, we have demonstrated polymorphism in the C-terminal region of the human NEFH: an allelic variant of a slightly larger molecular size, containing an additional KSP phosphorylation motif. Novel mutations in this region were found in five ALS patients. We propose that changes in the KSP-repeat domain may affect the cross-linking properties of the heavy neurofilament subunit and perhaps contribute to the development of neurofilamentous swellings in motor neurons, a hallmark of ALS.

    Human molecular genetics 1994;3;10;1757-61

  • Polymorphism in the multi-phosphorylation domain of the human neurofilament heavy-subunit-encoding gene.

    Figlewicz DA, Rouleau GA, Krizus A and Julien JP

    Centre for Research in Neuroscience, McGill University, Canada.

    The C-terminal region of the human neurofilament heavy subunit (NEFH) contains a unique functional domain consisting of 43 repeat motifs of the amino acids (aa) Lys-Ser-Pro (KSP) with either 3- or 5-aa spacers in between. Past studies have demonstrated that the serine in these KSP motifs can be phosphorylated, resulting in heavy phosphorylation of this domain. Recent studies provide strong evidence for a role of neurofilament phosphorylation in the establishment of neurofilament density and axonal caliber. Since it may be hypothesized that mutations in the phosphorylated region are a basis for neuropathological conditions, and since regions of the human genome containing repeat motifs have been demonstrated to be significantly polymorphic, we undertook to identify and characterize polymorphism in this region of the human NEFH gene. We were able to identify an allelic variant of a slightly larger molecular size, containing an additional KSP phosphorylation motif. The variant form of NEFH displays Mendelian inheritance and has a widespread population distribution. In addition, we also identified a point mutation in one individual which would result in a Pro-->Leu substitution in one of the repeat motifs.

    Gene 1993;132;2;297-300

  • Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2.

    Rouleau GA, Merel P, Lutchman M, Sanson M, Zucman J, Marineau C, Hoang-Xuan K, Demczuk S, Desmaze C, Plougastel B et al.

    Centre de recherche en Neuroscience, McGill University, Montreal, Quebec, Canada.

    Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease predisposing carriers to develop nervous system tumours. To identify the genetic defect, the region between two flanking polymorphic markers on chromosome 22 was cloned and several genes identified. One is the site of germ-line mutations in NF2 patients and of somatic mutations in NF2-related tumours. Its deduced product has homology with proteins at the plasma membrane and cytoskeleton interface, a previously unknown site of action of tumour suppressor genes in humans.

    Nature 1993;363;6429;515-21

  • A disease-associated germline deletion maps the type 2 neurofibromatosis (NF2) gene between the Ewing sarcoma region and the leukaemia inhibitory factor locus.

    Watson CJ, Gaunt L, Evans G, Patel K, Harris R and Strachan T

    University Department of Medical Genetics, St Mary's Hospital, Manchester, UK.

    RFLP typing of members of a neurofibromatosis type 2 (NF2) family suggested that affected individuals were hemizygous at the neurofilament heavy chain (NEFH) locus, possibly as a result of a disease-associated deletion. Conventional karyotyping revealed no evidence for a deletion and all or a majority of the affected family members were heterozygous for closely linked markers which mapped proximal to the NEFH locus (D22S1 and D22S56) and for the distal marker D22S32. FISH analysis confirmed a disease-associated germinal deletion on 22q which encompassed the NEFH locus, which is known to be very closely linked to NF2, but did not extend as far as the proximal Ewing sarcoma region or the distal leukaemia factor (LIF) locus. PFGE analysis with a LIF cosmid subclone identified patient-specific NotI and MluI fragments and suggested that the deletion is about 700 kb in length. Although this large deletion could be expected to eliminate a considerable fraction, and possibly all of the NF2 gene, the resulting phenotype is the mild, so-called Gardner subtype of NF2. The deletion should provide a useful mapping resource for characterising the chromosomal region containing the NF2 locus.

    Human molecular genetics 1993;2;6;701-4

  • Autoantigens in human neuroblastoma cells.

    Srinivasan J, Hays AP, Thomas FP, Sadiq SA, Barth KH, Liem R, Mena MA, DeYebenes JG and Latov N

    Department of Neurology, Columbia University, College of Physicians and Surgeons, New York City, NY 10032.

    Neuroblastoma cells are frequently used as targets in studies of autoimmune diseases of the nervous system. We examined the human neuroblastoma cell line, LAN-5, for the presence of autoantigens that react with naturally occurring autoantibodies in human sera. Antibodies to the HNK-1 and Gal(beta 1-3)GalNAc epitopes, which have been implicated in human autoimmune neuropathy and motor neuron disease, respectively, immunostained the surface of the neuroblastoma cells, and antibodies to the 200 kDa high molecular weight neurofilament protein (NFH) immunostained the cytoplasm and cell processes. The NHK-1 and Gal(beta 1-3)GalNAc epitopes were associated with several glycoprotein bands in Western blots of the neuroblastoma cells, and the HNK-1 epitope was also shared by a glycolipid which co-migrated with 3-sulfoglucuronyl paragloboside (SGPG) from peripheral nerve, indicating that SGPG is synthesized in neuronal cells. Northern blot analysis revealed a single RNA band of 4800 bp for NFH in normal brain but two RNA species of 4800 and 3800 bp in both neuroblastoma and adrenal cells, confirming their common origin. The neuroblastoma cells appear to contain antigens that bind to naturally occurring autoantibodies in human serum and might therefore be useful for detecting and investigating the effects of anti-neuronal antibodies. The antibody populations being investigated, however, should be distinguished from other autoantibodies which might be present in the patients' serum.

    Journal of neuroimmunology 1990;26;1;43-50

  • Characterization of two proteolytically derived soluble polypeptides from the neurofilament triplet components NFM and NFH.

    Chin TK, Harding SE and Eagles PA

    Department of Biophysics, King's College London, U.K.

    We have purified to homogeneity the regions derived by chymotryptic digestion of the ox neurofilament polypeptides NFH and NFM; the regions, called M1 and M2, are thought to form part of the projecting sidearms of mammalian neurofilaments [Chin, Eagles & Maggs (1983) Biochem. J. 215, 239-252]. They were isolated and purified under non-denaturing conditions and showed no tendency to interact with each other in solution. The Mr values obtained by sedimentation are approx. 61,000 for M1 and 42,000 for M2, considerably lower than the values obtained by SDS/polyacrylamide-gel electrophoresis. These Mr values were unchanged in the presence of 6 M-guanidine hydrochloride, suggesting that the regions exist as monomers in solution. Both M1 and M2 are highly phosphorylated, and there is only a slight change in the sedimentation value upon dephosphorylation. Dephosphorylation of M1 with alkaline phosphatase was more than 90% efficient but was never absolute. Dephosphorylation of M2 was complete. Both M1 and M2 bind Ca2+; in the case of M1, this binding is phosphorylation-dependent. M1 also binds cytochrome c, and dephosphorylation affects binding. In similar conditions, neurofilaments bind at least twice their own mass of cytochrome c, owing to their opposite net charges. No interactions were observed between native or dephosphorylated M1 and M2, and intact neurofilaments under a wide variety of conditions. These results are discussed in terms of the possible roles that neurofilament sidearms might play and throw doubt upon their supposed function of rigidly cross-linking neurofilaments together within the axoplasm of neurons.

    Funded by: Wellcome Trust

    The Biochemical journal 1989;264;1;53-60

  • The structure and organization of the human heavy neurofilament subunit (NF-H) and the gene encoding it.

    Lees JF, Shneidman PS, Skuntz SF, Carden MJ and Lazzarini RA

    Laboratory of Molecular Genetics, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, MD 20892.

    Genomic clones for the largest human neurofilament protein (NF-H) were isolated, the intron/exon boundaries mapped and the entire protein-coding regions (exons) sequenced. The predicted protein contains a central region that obeys the structural criteria identified for alpha-helical 'rod' domains typically present in all IF protein components: it is approximately 310 amino acids long, shares amino acid sequence homology with other IF protein rod domains and displays the characteristic heptad repeats of apolar amino acids which facilitate coiled-coil interaction. Nevertheless, anomalies are noted in the structure of the NF-H rod which could explain observations of its poor homopolymeric assembly in vitro. The protein segment on the carboxy-terminal side of the human NF-H rod is uniquely long (greater than 600 amino acids) compared to other IF proteins and is highly charged (greater than 24% Glu, greater than 25% Lys), rich in proline (greater than 12%) and impoverished in cysteine, methionine and aromatic amino acids. Its most remarkable feature is a repetitive sequence that covers more than half its length and includes the sequence motif, Lys-Ser-Pro (KSP) greater than 40 times. Together with the recent identification of the serine in KSP as the main target for NF-directed protein kinases in vivo, this repetitive character explains the massive phosphorylation of the NF-H subunit that can occur in axons. The human NF-H gene has three introns, two of which interrupt the protein-coding sequence at identical points to introns in the genes for the two smaller NF proteins, NF-M and NF-L.(ABSTRACT TRUNCATED AT 250 WORDS)

    Funded by: NIA NIH HHS: P0-AG06107

    The EMBO journal 1988;7;7;1947-55

Gene lists (6)

Gene List Source Species Name Description Gene count
L00000009 G2C Homo sapiens Human PSD Human orthologues of mouse PSD adapted from Collins et al (2006) 1080
L00000016 G2C Homo sapiens Human PSP Human orthologues of mouse PSP adapted from Collins et al (2006) 1121
L00000059 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-CONSENSUS Human cortex PSD consensus 748
L00000061 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-CONSENSUS Mouse cortex PSD consensus (ortho) 984
L00000069 G2C Homo sapiens BAYES-COLLINS-HUMAN-PSD-FULL Human cortex biopsy PSD full list 1461
L00000071 G2C Homo sapiens BAYES-COLLINS-MOUSE-PSD-FULL Mouse cortex PSD full list (ortho) 1556
© G2C 2014. The Genes to Cognition Programme received funding from The Wellcome Trust and the EU FP7 Framework Programmes:
EUROSPIN (FP7-HEALTH-241498), SynSys (FP7-HEALTH-242167) and GENCODYS (FP7-HEALTH-241995).

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