A NOVEL SPLICED TRANSCRIPT OF HUMAN CLAPS2 ENCODING A PROTEIN ALTERNATIVE TO CLATHRIN ADAPTOR PROTEIN AP17

Abstract Transcripts of genes encoding proteins of clathrin complexes have been reported to undergo tissue-specific alternative splicing. AP17, encoded by human CLAPS2 cDNA, is the small chain of the major clathrin adaptor complex AP-2 associated with mammalian plasma membranes. In this study, two cDNAs were isolated from a cDNA library of human blood cells. Whereas one cDNA encoded AP17, the other cDNA encoded a putative novel protein variant, termed AP17Δ. Both coding regions were completely sequenced. Consisting of 142 aa residues, the predicted protein AP17Δ of 12 kDa lacks 38 aa residues of AP17. Using specific primers for RT-PCR, mRNAs for AP17Δ and AP17 were found in leukocytes and cultured leukemia cells. The finding of a putative intron in a human EST cDNA clone suggests that mRNAs for AP17 and AP17Δ are formed by alternative splicing. In addition, the identity of human and rat AP17 amino acid sequences is demonstrated.