Molecular cloning of human testicular angiotensin-converting enzyme: the testis isozyme is identical to the C-terminal half of endothelial angiotensin-converting enzyme.
Angiotensin-converting enzyme (ACE; EC 3.4.15.1) is a zinc-containing dipeptidyl carboxypeptidase widely distributed in mammalian tissues and is thought to play a critical role in blood pressure regulation. Testis contains a unique, androgen-dependent ACE isozyme of unknown function. We have determined the cDNA sequence for human testicular ACE; it encodes a protein that is identical, from residue 37 to its C terminus, to the second half or C-terminal domain of the endothelial ACE sequence [Soubrier, F., Alhenc-Gelas, F., Hubert, C., Allegrini, J., John, M., Tregear, G. & Corvol, P. (1988) Proc. Natl. Acad. Sci. USA 85, 9386-9390]. The full-length human testis ACE cDNA was constructed from a composite of cloned cDNAs, obtained by a combination of (i) immunoscreening and hybridization screening of a human testicular cDNA library in lambda gt11 and (ii) hybridization screening of human testis cDNAs constructed with ACE-specific primers and amplified by the polymerase chain reaction. The protein sequence inferred consists of a 732-residue preprotein including a 31-residue signal peptide. The mature polypeptide has a molecular weight of 80,073. The testis enzyme contains the second of the two putative metal-binding sites (His-Glu-Met-Gly-His) identified in endothelial ACE. This indicates that the functionally active catalytic site is within the C-terminal domain of the endothelial enzyme, accounting for the previous finding that these two structurally dissimilar isozymes are virtually identical catalytically. Of 22 testis ACE cDNAs cloned and sequenced, 3 have unique 5' regions, consisting of inserted, deleted, or substituted sequences up to 328 base pairs long, which have apparently arisen by alternative pre-mRNA splicing.
Ehlers
M R
MR
Center for Biochemical and Biophysical Sciences and Medicine, Harvard Medical School, Boston, MA 02115.
Fox
E A
EA
Strydom
D J
DJ
Riordan
J F
JF
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics*; D004730:Endothelium, Vascular / Q000201:enzymology*; D005796:Genes; D015698:Genomic Library; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D007668:Kidney / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D008297:Male; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013737:Testis / Q000201:enzymology*; D014357:Trypsin
D007527:Isoenzymes; D004247:DNA; D007703:Peptidyl-Dipeptidase A; D014357:Trypsin