Molecular cloning and phylogenetic analysis of small GTPase protein Tscdc42 from Trichinella spiralis.

A full-length of complementary deoxyribonucleic acid (Tscdc42) encoding a putative Rho-family small GTPase gene cdc42 was isolated from Trichinella spiralis, an economically important parasitic nematode of zoonosis. The uninterrupted open reading frame of TsCDC42 encodes a predicted protein of 147 amino acids and containing a highly conserved domain of CDC42. Comparison with selected sequences from the free-living nematode Caenorhabditis elegans, Drosophila melanogaster, Xenopus laevis, Danio rerio, Mus musculus, and human showed that Tscdc42 is highly conserved. The highest identity of TsCDC42 with CDC42 from Drosophila is 67%, the similarity is up to 73%, the identity of TsCDC42 with the CDC42 homologue of C. elegans is 62%, and the similarity is up to 71%. Phylogenetic analysis of the amino acid sequence data, using the neighbor-joining and maximum parsimony methods, revealed that TsCDC42 is closely related to the molecule inferred from the cdc-42 gene of C. elegans. The transcript of TsCDC42 was analyzed during different stages of the worm.