INHIBITION OF RHODOPSIN PHOSPHORYLATION BY NON-MYRISTOYLATED RECOMBINANT RECOVERIN

Bovine recoverin regulates rhodopsin phosphorylation and controls phot oreceptor light sensitivity in a Ca2+-dependent manner. Recoverin is p ost-translationally modified with lipids (myristic acid or related lip ids) at its N-terminus. Since with this lipid modification (N-myristoy lation); recoverin associates with rod outer segment membranes in a Ca 2+-dependent manner, N-myristoylation has been suggested to be importa nt for the function of this protein. To study the role of this modific ation, we obtained recombinant non-myristoylated recoverin in E. coli and studied its functional properties. Here, we report that recombinan t non-myristoylated recoverin inhibits rhodopsin phosphorylation at Ca 2+ concentrations of 30 nM - 10 mu M in a similar way as native N-myri stoylated recoverin does. Thus, our result showed that N-myristoylatio n is not essential for the Ca2+-dependent inhibition of rhodopsin phos phorylation by recoverin. (C) 1994 academic Press, Inc.