Common antigenicity of mouse 42 degrees C-specific heat-shock protein with mouse HSP 105.

Mammalian cells incubated at 42 degrees C synthesize a specific heat-shock protein at 42 degrees C (42 degrees C-hsp) that is not induced by heat-shock at 45 degrees C or by other stresses that induce major heat shock proteins (Hatayama et al. (1986) Biochem. Biophys. Res. Commun. 137, 957-963). Antibody raised against a heat-shock protein with molecular weight of 105,000 (hsp 105) purified from mouse FM 3A cells cross-reacted to the 42 degrees C-hsp of the same cells. The antibody reacted only weakly to hsp 105 and 42 degrees C-hsp of human HeLa cells. These results suggested that hsp 105 and 42 degrees C-hsp have the same antigenic determinant, and that 42 degrees C-hsp may have a structure similar to that of hsp 105.