The expression of heat shock protein hsp27 and a complexed 22-kilodalton protein is inversely correlated with oncogenicity of adenovirus-transformed cells.
We isolated a monoclonal antibody that immunoprecipitated two proteins of 22 and 27 kilodaltons (kDa) from nononcogenic adenovirus type 5 early region 1 (E1)-transformed rat cells but not from oncogenic adenovirus type 12 E1-transformed rat cells. In a variety of adenovirus-transformed cells including cells transformed by E1A and the c-H-ras oncogene, we found a perfect, inverse correlation between the presence of these two proteins and the oncogenicity of these cells in syngeneic immunocompetent rats. Characterization of the two proteins revealed that they occur in a large (700-kDa) complex and that the 27-kDa protein is identical to the already known 27-kDa (28-kDa) heat shock protein hsp27. The suppression of the hsp27 protein in oncogenic cells is further demonstrated by the fact that its mRNA is absent even after heat-shock induction.
Zantema
A
A
Laboratory for Molecular Carcinogenesis, Sylvius Laboratoria, Leiden, The Netherlands.
de Jong
E
E
Lardenoije
R
R
van der Eb
A J
AJ
D000260:Adenoviruses, Human / Q000502:physiology*; D015152:Blotting, Northern; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D002850:Chromatography, Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D006360:Heat-Shock Proteins / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis
D006360:Heat-Shock Proteins; D011506:Proteins; D012333:RNA, Messenger; D012367:RNA, Viral