Abstract
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.
Acknowledgements
This work was supported by a Grant for Scientific Research (No. S0607) from the School of Veterinary Medicine and Animal Sciences, Kitasato University and by a Grant-in-Aid for Scientific Research (No. 17580271) from the Japan Society for the Promotion of Science (JSPS).
Notes
†Sequence data in this article have been deposited with the EMBL/GenBank/DDBJ Data Libraries under Accession No. AB2129 58