Cloning and sequence analysis of prothymosin-α cDNA of Bufo japonicus formosus

Abstract

To study the polypeptide effective components included in the skin of Bufo japonicus formosus （Japanese toad） and their secretions，the full length cDNAs were screened from the plasmid cDNA library of adult Japanese toad skin using colony polymerase chain reaction with a pair of primers，SP6 （the upstream primer of the vector） and poly（T） （a self-designed primer recognizing the area connecting polyA tail of cDNA and the vector）. Results showed that a prothymosin- （ProT） cDNA was obtained from 1 344 colonies checked，whose transcript was 1 480 bp in length consisting of 125 bp in the 5 prime untranslated region （5 UTR） and 1 016 bp 3 UTR with a complete open reading frame （ORF） of 339 bp encoding a polypeptide of 112 amino acid residues. The homologous analysis indicated a similarity between B. japonicus formosus and Rana esculenta of up to 82%，but for other species it was 54%-73%. Previous studies have shown significant anti-tumor effects of ProT; therefore，this study could contribute to further studies on ProT.［Ch，4 fig. 17 ref.］