Isolation of cDNA clones of rabbit angiotensin converting enzyme: identification of two distinct mRNAs for the pulmonary and the testicular isozymes.

We have isolated cDNA clones of rabbit angiotensin converting enzyme. These clones were isolated by antibody-screening of a lambda gt11 expression library made from rabbit testicular mRNA. The 2.6 kb insert of one such clone was subcloned in pBR322 and used as a hybridization probe. Out of the twenty independently isolated clones only seven hybridized with this probe suggesting that these clones belong to at least two families. Northern analysis revealed the presence of a 2.6 kb mRNA in rabbit testes and a 5.0 kb mRNA in rabbit lungs which hybridized strongly with this probe. These results indicate that the two tissue-specific isozymic forms of angiotensin converting enzyme are encoded by two distinct mRNAs which share sequence homologies.