Messenger RNA

Receptor

Enzyme

Cell culture

Biology

Gene

Neprilysin

Endothelin receptor

Endothelin 1

Molecular biology

Complementary DNA

Chemistry

Phosphoramidon

Cell biology

Cytosol

Genetics

Biochemistry

Journal of Cardiovascular Pharmacology

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.

Phosphoramidon-Sensitive and-Insensitive Endothelin-Converting Enzyme in Human Megakaryoblastic Cell Lines