title: Characterization of proteins associated with heat shock protein hsp27 in the squamous cell carcinoma cell line A431.
abstract: Heat shock protein hsp27 is a molecular chaperone and identification of hsp27-binding proteins might help to elucidate its functional role in keratinocyte biology. In the present investigation we used a human epidermal cell carcinoma cell line (A431) transfected with hsp27 (A431/16) to study interference between hsp27 protein and other proteins. Immunoprecipitation experiments with anti-hsp27 antibody revealed a multicomponent complex when analysed by silver staining. By immunoblotting analysis we could demonstrate that hsp27 associates with actin, the mutant form of p53, hsp70 and hsp90. Immunofluorescence analysis showed a co-localization between hsp27 and p53, hsp70 and hsp90. To control for the specificity of the observed interactions, immuno-precipitations with antibodies to actin, p53, hsp70 and hsp90 respectively, were performed. All of the tested proteins demonstrated a coimmunoprecipitation with hsp27. We conclude that hsp27, like the other heat shock proteins, is part of a complex system of molecular chaperones in epidermal keratinocytes.
authors.affiliation: Department of Applied and Experimental Oncology, Institute of Tumorbiology/Cancer Research, Vienna, Austria. margaret.kindas-muegge@univie.ac.at
authors.forename: Ingela
authors.initials: I
authors.lastname: Kindas-Mügge
authors.forename: Constanze
authors.initials: C
authors.lastname: Rieder
authors.forename: Ilse
authors.initials: I
authors.lastname: Fröhlich
authors.forename: Michael
authors.initials: M
authors.lastname: Micksche
authors.forename: Franz
authors.initials: F
authors.lastname: Trautinger
authors.forename: Constanze
authors.initials: C
authors.lastname: Riedler
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins; D006801:Humans; D015151:Immunoblotting; D015603:Keratinocytes / Q000378:metabolism; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D016622:Silver Staining; D012878:Skin Neoplasms / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53