title: Small heat shock protein alphaB-crystallin is part of cell cycle-dependent Golgi reorganization.
abstract: AlphaB-crystallin is a developmentally regulated small heat shock protein known for its binding to a variety of denatured polypeptides and suppression of protein aggregation in vitro. Elevated levels of alphaB-crystallin are known to be associated with a number of neurodegenerative pathologies such as Alzheimer disease and multiple sclerosis. Mutations in alphaB-crystallin gene have been linked to desmin related cardiomyopathy and cataractogenesis. The physiological function of this protein, however, is unknown. Using discontinuous sucrose density gradient fractionation of post-nuclear supernatants, prepared from rat tissues and human glioblastoma cell line U373MG, we have identified discrete membrane-bound fractions of alphaB-crystallin, which co-sediment with the Golgi matrix protein, GM130. Confocal microscopy reveals co-localization of alphaB-crystallin with BODIPY TR ceramide and the Golgi matrix protein, GM130, in the perinuclear Golgi in human glioblastoma U373MG cells. Examination of synchronized cultures indicated that alphaB-crystallin follows disassembly of the Golgi at prometaphase and its reassembly at the completion of cytokinesis, suggesting that this small heat shock protein, with its chaperone-like activity, may have an important role in the Golgi reorganization during cell division.
authors.affiliation: Jules Stein Eye Institute, University of California, Los Angeles 90095-7000, USA.
authors.forename: Rajendra K
authors.initials: RK
authors.lastname: Gangalum
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Schibler
authors.forename: Suraj P
authors.initials: SP
authors.lastname: Bhat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D017124:Conserved Sequence; D006056:Golgi Apparatus / Q000502:physiology / Q000648:ultrastructure*; D018613:Microscopy, Confocal; D010446:Peptide Fragments; D051381:Rats; D017207:Rats, Sprague-Dawley; D038203:alpha-Crystallin B Chain / Q000502:physiology*
chemical_list: D010446:Peptide Fragments; D038203:alpha-Crystallin B Chain