title: Interaction of small heat shock proteins with light component of neurofilaments (NFL).
abstract: The interaction of human small heat shock protein HspB1, its point mutants associated with distal hereditary motor neuropathy, and three other small heat shock proteins (HspB5, HspB6, HspB8) with the light component of neurofilaments (NFL) was analyzed by differential centrifugation, analytical ultracentrifugation, and fluorescent spectroscopy. The wild-type HspB1 decreased the quantity of NFL in pellets obtained after low- and high-speed centrifugation and increased the quantity of NFL remaining in the supernatant after high-speed centrifugation. Part of HspB1 was detected in the pellet of NFL after high-speed centrifugation, and at saturation, 1 mol of HspB1 monomer was bound per 2 mol of NFL. Point mutants of HspB1 associated with distal hereditary motor neuropathy (G84R, L99M, R140G, K141Q, and P182S) were almost as effective as the wild-type HspB1 in modulation of NFL assembly. At low ionic strength, HspB1 weakly interacted with NFL tetramers, and this interaction was increased upon salt-induced polymerization of NFL. HspB1 and HspB5 (αB-crystallin) decreased the rate of NFL polymerization measured by fluorescent spectroscopy. HspB6 (Hsp20) and HspB8 (Hsp22) were less effective than HspB1 (or HspB5) in modulation of NFL assembly. The data presented indicate that the small heat shock proteins affect NFL transition from tetramers to filaments, hydrodynamic properties of filaments, and their bundling and therefore probably modulate the formation of intermediate filament networks in neurons.
authors.affiliation: Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991.
authors.forename: Victoria V
authors.initials: VV
authors.lastname: Nefedova
authors.affiliation: Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Sudnitsyna
authors.affiliation: Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991. NBGusev@mail.ru.
authors.forename: Nikolai B
authors.initials: NB
authors.lastname: Gusev
mesh_terms: D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins; D050888:Heat-Shock Proteins, Small / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007382:Intermediate Filaments / Q000378:metabolism* / Q000473:pathology; D018832:Molecular Chaperones; D009134:Muscular Atrophy, Spinal / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D017354:Point Mutation; D060066:Protein Interaction Maps
chemical_list: D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D050888:Heat-Shock Proteins, Small; D018832:Molecular Chaperones
keywords: Cytoskeleton; Intermediate filaments; Neurodegenerative diseases; Neurofilaments; Small heat shock proteins