CHICKEN LACKS THE TESTIS-SPECIFIC ISOZYME OF ANGIOTENSIN-CONVERTING ENZYME FOUND IN MAMMALS

Chicken angiotensin converting enzyme (ACE) cDNA was cloned based on h omology to the mouse ACE sequence. The chicken ACE protein is highly h omologous to the somatic isozyme of ACE found in human, mouse, bovine, and rabbit. Like the mammalian somatic forms, the chicken enzyme cons ists of two putative zinc binding sites at the center of two homologou s domains. All known functional residues are absolutely conserved. Unl ike the mammals, no evidence for a single domain, testis specific form of ACE was found in the chicken testis by either Northern blot or enz yme assay. This result is unexpected since the adult mammalian testis expresses one of the highest tissue levels of ACE. (C) 1994 Academic P ress. Inc.