Mouse neuroblastoma-rat retina hybrid cell lines were established to rescue the expression of retinal genes. A monoclonal antibody that binds to cells from ne hybrid line recognizes an antigen expressed by few cell types in retina and brain. cDNA corresponding to the neural antigen was cloned and sequenced. Additional monoclonal antibodies were obtained that bind to antigens that are markers of cell types in retina. Clones for 4 species of alpha s cDNA and 1 alpha s genomic DNA were obtained that correspond to the alpha s subunit of GS signal transduction protein. Two alpha i-1 cDNA clones were obtained and sequenced. In addition, DNA clones for rat and human alpha o genes were obtained. Monospecific antibodies to an alpha- subunit of voltage-sensitive Ca2+ channels from rat T-tubules were shown to activate voltage-sensitive calcium channels of parathyroid cells. Both cDNA and genomic DNA clones were obtained that correspond to species of poly A+ RNA that increase of decrease tn abundance when cells are treated with dibutyryl cAMP. TOP, a cell membrane protein that is distributed in a dorsal-ventral topographic gradient in chick retina was shown to be distributed in an inverted but matching ventral-dorsal gradient in chick embryo tectum. Proteins rich in lysine markedly stimulate the activity of a protein kinase in Xenopus oocyte membranes and NG108-15 membranes. NG108- 15 phosphatidylinositol-4,5-bisphosphate and accumulation of inositol-1,4,5-trisphosphate, which releases Ca2+from intracellular stores, and diacylglycerol, which activates protein kinase C. Cytoplasmic Ca2+ activates a Ca2+-dependent K+ channel leading to cell hyperpolarization. The activation of protein kinase C by bradykinin leads to an increase in the phosphorylation of 4 proteins and the inhibition of M-channels. Activation of protein kinase C greatly potentiates Ca2+ dependant acetylcholine secretion from NG108-15 cells.