Immunological detection of a CK2 activity in Tapes semidecussatus (Mollusca, Bivalvia) mantle

Casein kinase 2 (CK2) is a highly conserved enzyme present in a wide range of eukaryotes, including yeasts, invertebrates and mammals. This kinase is involved in a number of key regulatory cellular processes. We describe a CK2-like protein in mantle tissue of Tapes semidecussatus, a highly active organ responsible for cell healing and regeneration in this clam species. After subcellular fractionation of crude homogenized mantles, the putative enzymatic activity was clearly enriched after two-step cromatography partial purification. Furthermore, using a polyclonal antibody elicited against the known subunits of the mammalian enzyme, Western blot analysis confirmed the presence of three reactive polypeptides. Two of these perfectly matched the expected molecular weights of the catalytic α (42 kDa) and α′ (38 kDa) subunits of the reference enzyme. Considering our research interest is centered on the relationship between marine organisms and their environment, our preliminary work on a CK2-like kinase in clams offers a potential model system to study protein phosphorylation in molluscs as an indicator of the effect of environment factors over selected physiological responses.