SCL binds the human homologue of DRG in vivo.

A suspected oncoprotein, human development regulated GTP-binding protein (DRG) has never been identified though homologues were found in mouse, Xenopus, Drosophila, yeast and Halobacteria. During a search for SCL binding partners using the yeast 2-hybrid system, we isolated two independent cDNA clones (clone L51 and clone V3) of the human DRG homologue from human fetal liver and human thymus cDNA libraries. Only one amino acid difference was found between human and mouse DRG proteins. Although a human DRG has been previously deposited in the SWISS-PROT Database, we believe that we have cloned the bona fide human DRG based on the highly conserved primary amino acid structure between our cloned human homologue and the mouse DRG.