Cloning and embryonic expression of Xenopus laevis GAP-43 (XGAP-43).

Xenopus laevis GAP-43 (XGAP-43) is highly related to other vertebrate GAP-43 proteins in its N-terminal region which contains a membrane-targeting sequence, serine phosphorylation site, and calmodulin binding domain. Unlike other species examined, however, there appear to be two GAP-43-class genes in X. laevis which resulted from the genome duplication in Xenopus approximately 30 million years ago. During embryogenesis, XGAP-43 is expressed in a complex spatiotemporal pattern that is consistent with its putative role in neuronal growth and development.