title: Ubiquitous and cell-specific members of the avian small heat shock protein family.
abstract: Small heat shock proteins (sHsps) have been suggested to act as molecular chaperones for many kinds of substrates and have protective roles in cells exposed to external stresses. Unlike other major Hsps such as Hsp70 and Hsp90, expression of many vertebrate sHsps is restricted to the muscle tissues and/or eye lens. Among the sHsps, the heat-inducible human Hsp27 (hHsp27) homologue is believed to be expressed ubiquitously in various cell types. Here, we distinguished the chicken homologue of hHsp27 (cHsp24) from the chicken major heat-inducible protein of molecular size 25 kDa (cHsp25). cHsp25 is not expressed in the absence of stress, but is highly expressed after hyperthermia in all tissues of developing embryos. In contrast, expression of cHsp24 is restricted to some specific tissues even in the presence of stress. Thus, cHsp25 is the first member of the sHsps in vertebrates the expression of which is ubiquitous in tissues exposed to external stresses similar to Hsp70.
authors.affiliation: Department of Molecular and Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kawazoe
authors.forename: M
authors.initials: M
authors.lastname: Tanabe
authors.forename: A
authors.initials: A
authors.lastname: Nakai
mesh_terms: D000818:Animals; D002642:Chick Embryo; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins