title: Knock down of heat shock protein 27 (HspB1) induces degradation of several putative client proteins.
abstract: Hsp27 belongs to the heat shock protein family and displays chaperone properties in stress conditions by holding unfolded polypeptides, hence avoiding their inclination to aggregate. Hsp27 is often referenced as an anti-cancer therapeutic target, but apart from its well-described ability to interfere with different stresses and apoptotic processes, its role in non-stressed conditions is still not well defined. In the present study we report that three polypeptides (histone deacetylase HDAC6, transcription factor STAT2 and procaspase-3) were degraded in human cancerous cells displaying genetically decreased levels of Hsp27. In addition, these proteins interacted with Hsp27 complexes of different native size. Altogether, these findings suggest that HDAC6, STAT2 and procaspase-3 are client proteins of Hsp27. Hence, in non stressed cancerous cells, the structural organization of Hsp27 appears to be a key parameter in the regulation by this chaperone of the level of specific polypeptides through client-chaperone type of interactions.
authors.affiliation: Centre de Génétique Moléculaire et Cellulaire, CNRS UMR5534, Université Lyon 1, Université de Lyon, Villeurbanne, France. benjamin.gibert@lyon.unicancer.fr
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gibert
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Eckel
authors.forename: Lydie
authors.initials: L
authors.lastname: Fasquelle
authors.forename: Maryline
authors.initials: M
authors.lastname: Moulin
authors.forename: Frantz
authors.initials: F
authors.lastname: Bouhallier
authors.forename: Vincent
authors.initials: V
authors.lastname: Gonin
authors.forename: Gregory
authors.initials: G
authors.lastname: Mellier
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Simon
authors.forename: Carole
authors.initials: C
authors.lastname: Kretz-Remy
authors.forename: André-Patrick
authors.initials: AP
authors.lastname: Arrigo
authors.forename: Chantal
authors.initials: C
authors.lastname: Diaz-Latoud
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000502:physiology; D055785:Gene Knockdown Techniques; D055551:HSP27 Heat-Shock Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D006367:HeLa Cells; D006360:Heat-Shock Proteins; D006801:Humans; D018832:Molecular Chaperones / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D011506:Proteins / Q000378:metabolism*; D059748:Proteolysis / Q000187:drug effects*; D034741:RNA, Small Interfering / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D011506:Proteins; D034741:RNA, Small Interfering