Multiple p53 protein isoforms and formation of oligomeric complexes with heat shock proteins Hsp70 and Hsp90 in the human mammary tumor, T47D, cell line.

摘要: At least eleven isoforms of p53 protein were observed in a human mammary tumor cell line. T47D. Comparative 33P and 35S incorporation analysis showed an equal distribution P53 within cytoplasmic nuclear compartments, although phosphorylation was unequal among the most basic species unphosphorylated. Using combination immunoprecipitation with monoclonal antibodies for heat shock proteins Hsp70 & Hsp90, two-dimensional gel electrophoretic analysis, T47D oligomers several Hsp90. The p53/Hsp70/Hsp90 aggregate dissociates after translocation. Immunoprecipitation Hsp90 using formation heteroligomer between cytoplasm but not nucleus. This suggests these Hsp can form complex undergo conformational change translocation such that Hsp/Hsp binding sites are no longer recognized. These data indicate cells have multiple precursor molecules probably at different stages phosphorylation, which may be sequestered from proteases by to proteins. also heterocomplex cytoplasm, possibly as protection against protease degradation until bound p53. After translocation, is freed DNA where able rendering Hsp's labile proteolysis.