Molecular cloning of the S-antigen cDNA from bovine retina.

S-antigen is the major component of the soluble proteins in the retina and the pineal, and is thought to play a regulatory role in the visual cycle. It induces experimental autoimmune uveitis (E.A.U.) in various species of laboratory animals. We have cloned the cDNA of S-antigen from bovine retina, containing the entire coding region, and determined its nucleotide sequence. The sequence consists of a 1212 nucleotide region that specific the amino acid sequence, a 368 nucleotide 5' untranslated region and a 80 nucleotide 3' untranslated region. The previously reported partial amino acid sequence defining the carboxy terminal moiety of the polypeptide, fits into our sequence. Homologies were found between the predicted amino acid sequence of S-antigen and that of alpha transducin.