Cloning of bovine preproendothelin-2 cDNA and organ distribution of transcripts

cDNA cloning of hamster angiotensin-converting enzyme and mRNA expression

Angiotensin-converting enzyme (ACE; EC 3.4.15.1), a dipeptidyl carboxypeptidase, converts angiotensin I to angiotensin II, the central product of the renin-angiotensin system. We here report molecular cloning of the complete open reading frame (ORF) of hamster somatic-type ACE and its expression in hamster organs. The cloned cDNA comprises an ORF of 3942 bp, which encodes 1314 amino acids of the precursor protein of hamster somatic ACE. On the deduced amino acid sequence a putative signal peptide and a transmembrane segment are predicted at the N-terminus and near the C-terminus, respectively. Two homologous domains, referred to as N- and C-domains, are present within somatic ACE, and within each of the homologous domains a putative active center is found, as has been the case in human, mouse, rat and rabbit. The similarity of the hamster sequence with the sequences of these other mammals at both the nucleotide and amino acid levels is high (above 83%). mRNA expression analysis by conventional polymerase chain reaction (PCR) shows wide distribution of the transcript, with dominant expression in lung and kidney. Quantitative analysis of mRNA expression demonstrates that levels in lung and kidney are 100-1000 times higher than in the other organs, suggesting that these organs are important in the hamster renin-angiotensin system, as they are for other mammals.

Expression of preproendothelin-2 splice variant in cat

Previous studies on human uterine and placental tissues have found variants, derived from alternatively spliced mRNAs, of preproendothelin-2 (PPET2) that lack a post-translational proteolytic site essential for normal processing. Here we report a splice variant of cat PPET2 mRNA expressed in the stomach. After cloning the full-length cDNA of cat PPET2, organ distribution analysis of the transcript by reverse transcriptase-polymerase chain reaction (RT-PCR) was performed. In addition to the fragment with a size predicted based on the cDNA sequence obtained by cloning, an additional PCR fragment of smaller size was detected in stomach tissue. Subsequent cloning and sequence analysis of the smaller PCR product demonstrated that it derives from a splice variant with full-length deletion of a region corresponding to exon 4 of the PPET2 gene.