Phosphoramidon-sensitive and -insensitive endothelin-converting enzyme in human megakaryoblastic cell lines.
The human megakaryoblastic cell lines HEL, MEG-01, and DAMI express preproendothelin-1 mRNA. This investigation was designed to find out whether they could also express endothelin-converting enzyme (ECE) and release mature endothelin (ET). RT-PCR applied to RNA isolated from the cell lines amplified fragments of the expected size. The amplified cDNA of MEG-01 was submitted to restriction enzymes, which generated the expected subfragments. Membrane ECE activity was phosphoramidon-sensitive, in contrast to the cytosolic activity capable of producing ET-1 from big ET-1. The three cell lines produced ir-ET in a time-dependent manner. These results show that human megakaryoblastic cell lines express functional, phosphoramidon-sensitive and insensitive ECE activity and produce mature ET.
Hamroun
D
D
INSERM U. 469, Montpellier, France.
Dumas
J
J
Mathieu
M N
MN
Launay
J M
JM
Chevillard
C
C
D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D002460:Cell Line; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D019332:Endothelin-1 / Q000096:biosynthesis; D000072396:Endothelin-Converting Enzymes; D006020:Glycopeptides / Q000494:pharmacology*; D006801:Humans; D008533:Megakaryocytes / Q000187:drug effects / Q000201:enzymology*; D008566:Membranes / Q000201:enzymology; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D016133:Polymerase Chain Reaction; D011480:Protease Inhibitors / Q000494:pharmacology*
D018076:DNA, Complementary; D019332:Endothelin-1; D006020:Glycopeptides; D011480:Protease Inhibitors; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes; C008890:phosphoramidon