Translation in a cell-free system, and in Xenopus oocytes, of mRNA which specify a cadmium-binding protein in Nereis diversicolor (annelida, polychaeta)

The presence in the marine worm Nereis diversicolor of a low molecular mass protein with the capacity to bind cadmium has been previously demonstrated [5].

Poly(A)⁺-mRNA were extracted from coelomocytes of Nereis diversicolor and were translated either in vitro, using a rabbit reticulocyte lysate, or in vivo into Xenopus laevis oocytes. Analysis of synthesized polypeptides by enzyme-linked immunosorbent assay (ELISA) and by Western blotting, using a specific monoclonal anti-MP II antibody, showed that this metalloprotein was translated both in in vitro and in vivo translation systems, with an apparent molecular mass of 11–13 kDa. Two other products, with 26.5 and 28 kDa molecular mass, cross-reacted with the monoclonal anti-MP II antibodies. The present work confirms that coelomocytes are sites of important synthesis of MP II-mRNA.