Search results for "Annexins"

Demonstration of an endocrine signaling circuit for insulin in the sponge Geodia cydonium.

1989

Abstract The existence of an insulin-mediated cell-to-cell signaling in the sponge Geodia cydonium is demonstrated in this study by molecular biological and immunological techniques. The sequence of a sponge cDNA clone encoding preproinsulin was analyzed for the first time and determined to comprise a high homology to human preproinsulin (60-80% homology). The predicted polypeptide of preproinsulin from sponge contains two disulfide bridges which link the A- to the B-chain. The intra-A chain disulfide bridge is absent. Applying immunological and electron microscopical techniques it is shown that insulin is produced in specialized cells (spherulous cells). Experimental evidence is presented …