THE SIMULTANEOUS IMMUNOLOGICAL DETECTION OF 4 STRESS-70 PROTEIN ISOFORMS IN MYTILUS-EDULIS

Organisms exposed to adverse environmental conditions exhibit a stress-70 protein response which is highly conserved from bacteria to man. Immunological analysis of the stress-70 response in mussels is of interest for its potential use in marine biomonitoring. We have analysed the gill tissues of Mytilus edulis individuals for changes in stress-70 complement after exposure to 48 h of temperature stress. Using a commercially available monoclonal antibody raised against human hsp70 and epitope mapped to a conserved ATP binding region, the authors were able to detect by western analysis constitutively-expressed 72kDa and 78kDa isoforms in control animals acclimated at normal temperatures. After 48 h of heat stress, induction of a 70kDa protein was clearly seen along with an increase in the level of the 72kDa protein. Western analysis using two-dimensional gel electrophoresis indicated that the antibody recognised four stress-70 isoforms (70, 72, 72 and 78kDa). This simultaneous detection of four members of the stress-70 family will permit studies on the differential regulation of each of the four members of the multigene family in response to a variety of environmental stressors.