CADMIUM RESISTANCE OF ACHLOROPHYLLOUS EUGLENA-GRACILIS CELLS - CONSTITUTIVE OVEREXPRESSION OF 2 HEAT-SHOCK PROTEINS

The heat-shock response of Euglena gracilis was studied by cell labeli ng at both the normal growth temperature (23 degrees C) and an elevate d temperature (35 degrees C). Analysis of the labeled proteins by two- dimensional polyacrylamide gel electrophoresis indicated that the rate of synthesis of two polypeptides p55 (55 kDa) and p40 (40 kDa) increa sed in cells labeled at the highest temperature studied. These polypep tides are also overexpressed in Cadmium-resistant Euglena gracilis cel ls labeled at the normal growth temperature (23 degrees C). On the bas is of these results, p55 and p40 appear to be heat-shock proteins invo lved in some steps of the acquired Cd-resistance process in Euglena gr acilis cells. (C) 1994 Academic Press, Inc.