[Cloning and bioinformatic analysis of TAGLN2 cDNA of Bufo japonicus formosus].

To study the bioactive polypeptides included in Bufo skin and its secretions the plasmid skin cDNA library of adult Japanese toad Bufo japonicus formosus was prepared. The pSD64TR has been used as the vector and the cloning sites are Xho I and EcoR I. To screen cDNAs encoding bioactive components, the plasmid cDNA library was transformed into E. coli DH5 competent cells, and positive colonies were screened by colony PCR (polymerase chain reaction). The suspension of a single colony in LB medium was used as the template, SP6 (the upstream primer of the plasmid cDNA library) and a primer with Xho I site and polyT were used as the primers. As the result, 465 positive colonies out of 1 344 were obtained and their plasmid were collected and sequenced. By homologous analysis, it was found that one of the cDNAs encoding a peptide with high homolog with transgelin-2, which was registered in GenBank (accession number: JX197456), and it was indicated as a partial cDNA sequence with a deletion at the 5' end. The transcript is 997 bp consisting of 31 bp 5', 618 bp 3' untranslated region (UTR) and an open reading frame (ORF) of 348 bp encoding a polypeptide of 115 amino acids. In the putative protein product, there is a calponin homology domain, two cysteine residues for a disulfide bond and three a-helix domains, and five potential phosphorylation sites. The homologous analysis indicates 90% similarity with Xenopus (Silurana) tropicalis and 89% with Xenopus laevis, and 71%-85% with other species.