αA‐crystallin confers cellular thermoresistance

Abstract

The bovine eye lens protein αA‐crystallin has been overexpressed both by stable transfection of HeLa cells and by transient transfection of NIH 3T3 cells. In both experimental systems αA‐crystallin overexpression results in an increased cellular thermoresistance as judged by different clonal survival assays. In contrast, similar overexpression of another stable lens protein, βB2‐crystallin, does not confer thermoresistance. These results indicate that the structural relationship of αA‐crystallin to the small heat shock proteins HSP25/27 and to αB‐crystallin is sufficient for the shared thermoprotective function of all of these molecules and strongly suggests that the chaperone‐like properties that they have in common are responsible for the conferred cellular thermoresistance.