Molecular isolation and characterization of novel four subisoforms of ECE-2.
Endothelin-converting enzymes (ECEs) are the key enzymes in the endothelin (ET) biosynthesis that catalyze the conversion of big ET, the biologically inactive precursor of mature ET. Two enzymes, termed ECE-1 and ECE-2, have been molecularly identified. Here, we report novel four subisoforms of ECE-2 that differ in their N-terminal cytoplasmic tails, termed ECE-2a-1, ECE-2a-2, ECE-2b-1, and ECE-2b-2. RT-PCR analysis of these subisoforms in bovine tissues demonstrated that their tissue distribution was strikingly different. ECE-2a-1 and ECE-2a-2 are expressed in a variety of tissues including liver, kidney, adrenal gland, testis, and endothelial cells, while ECE-2b-1 and ECE-2b-2 are expressed abundantly in brain and adrenal gland. Furthermore, ECE-2a-1 and ECE-2b-2 were revealed to be predominant forms as compared to ECE-2a-2 and ECE-2b-1, respectively. Immunohistochemical analyses of CHO cells, stably expressing ECE-2a-1 or ECE-2b-2, revealed that both ECE-2a-1 and ECE-2b-2 were localized in intracellular compartments but not on the cell surface. Detailed analysis of ECE-2 subisoforms will provide crucial information to clarify the physiological function of ECE-2.
Ikeda
Shoko
S
Division of Molecular Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki, Chuo, Kobe 6500017, Japan.
Emoto
Noriaki
N
Alimsardjono
Haryanto
H
Yokoyama
Mitsuhiro
M
Matsuo
Masafumi
M
D000311:Adrenal Glands / Q000201:enzymology; D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D001921:Brain / Q000201:enzymology; D016466:CHO Cells; D002417:Cattle; D006224:Cricetinae; D000072396:Endothelin-Converting Enzymes; D004730:Endothelium, Vascular / Q000201:enzymology; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D008099:Liver / Q000201:enzymology; D008297:Male; D008666:Metalloendopeptidases; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000201:enzymology; D014162:Transfection
D007527:Isoenzymes; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; C000606923:ECE1 protein, human; C000606924:ECE2 protein, human; C000606925:Ece1 protein, mouse; C000606926:Ece2 protein, mouse; D000072396:Endothelin-Converting Enzymes