DrosophilaNeurocalcin, a Fatty Acylated, Ca-binding Protein that Associates with Membranes and Inhibitsin VitroPhosphorylation of Bovine Rhodopsin

Eva Faurobert, Ching-Kang Chen, James B. Hurley, David Heng-Fai Teng
1996 Journal of Biological Chemistry  
1994) J. Biol. Chem. 269, 31900 -31907). We showed that the Drosophila neurocalcin protein (DrosNCa) is expressed in neurons and that bacterially expressed recombinant DrosNCa (rDrosNCa) can be myristoylated. Here, we present two lines of evidence that DrosNCa is fatty acylated in vivo. First, the mobility of affinity-purified native DrosNCa on two-dimensional gel electrophoresis is identical to that of myristoylated rDrosNCa and distinct from that of nonacylated rDrosNCa. Second, the membrane
more » ... inding properties of native DrosNCa are similar to those of myristoylated rDrosNCa; both of these proteins bind to membranes at 0.2 mM Ca 2؉ , whereas nonacylated rDrosNCa always remains soluble. It has been shown that recoverin inhibits the phosphorylation of rhodopsin when Ca 2؉ is present (Kawamura et al., et al., 1995) . Given the similarities between recoverin and neurocalcin, we examined the effect of DrosNCa on rhodopsin phosphorylation. We find that rDrosNCa is capable of inhibiting bovine rhodopsin phosphorylation in vitro in a Ca 2؉ -dependent manner. The inhibitory activity of rDrosNCa is enhanced by myristoylation, and the potency of its effect is similar to that of recoverin. Two other related EF hand proteins, guanylate cyclaseactivating protein-2 and calmodulin, are only poor inhibitors in these phosphorylation assays. in vitro inhibition of rhodopsin phosphorylation therefore appears to be an assayable property of a subset of recoverin-like proteins. 1993) and that a dependent recoverin/rhodopsin kinase interaction underlies the inhibitory effect of recoverin (Chen
doi:10.1074/jbc.271.17.10256 pmid:8626592 fatcat:o7kajl3fsfcqbemqn6ihe57jz4