Isolation of the gene coding for Caenorhabditis elegans Rac2 homologue, a Ras-related small GTP-binding protein

When screening a Caenorhabditis elegans genomic library using the human Rac1 cDNA as probe, a hybridizing fragment of 2.7 kb was isolated which contained four exons with high sequence similarity to CeRac1, coding for the nematode homologue of the Ras-related small GTP-binding protein Rad. The putative translational product of 195 amino acids (aa) from the exons displayed 88% identity to the sequence of CeRac1. Interestingly, three alterations were found in the N-terminal 'effector domain' (residues 22-45) which hitherto was identical among all known Rac p21s, suggesting that CeRac2 might have different targets/functions for nematode development. Additionally, an insertion of 4 aa was found in the hypervariable region at the C terminus of CeRac2.