Human endothelin-converting enzyme (ECE-1): three isoforms with distinct subcellular localizations
| Autor: | Anja Schweizer, Olivier Valdenaire, U Deuschle, J G Stumpf, P Nelböck, J B Dumas Milne Edwards, Bernd-Michael Löffler |
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| Rok vydání: | 1998 |
| Předmět: |
medicine.hormone
Gene isoform Endothelin converting enzyme 1 Molecular Sequence Data Fluorescent Antibody Technique Golgi Apparatus CHO Cells Biology Endothelin-Converting Enzymes Biochemistry Isozyme Cell Line Endothelins Ribonucleases Cricetinae medicine Animals Aspartic Acid Endopeptidases Humans Ribonuclease Amino Acid Sequence RNA Messenger Cloning Molecular Protein Precursors education Promoter Regions Genetic Molecular Biology Peptide sequence education.field_of_study Messenger RNA Base Sequence Endothelin-1 Cell Membrane Metalloendopeptidases Cell Biology Sequence Analysis DNA Endothelin 1 Molecular biology Isoenzymes Kinetics biology.protein Research Article |
| Zdroj: | The Biochemical journal. 328 |
| ISSN: | 0264-6021 |
| Popis: | Endothelin-converting enzyme 1 (ECE-1) is a membrane-bound metalloprotease that catalyses the conversion of inactive big endothelins into active endothelins. Two different isoforms (ECE-1a and ECE-1b) have previously been identified for human ECE-1. In the present study we have cloned a novel human ECE-1 isoform, termed ECE-1c, and have thus shown for the first time the existence of three distinct ECE-1 isoforms. The three isoforms differ only in their N-terminal regions and are derived from a single gene through the use of alternative promoters. Ribonuclease protection experiments revealed that, although the relative levels of the three isoform mRNA species vary between human tissues, ECE-1c mRNA is generally the predominant isoform messenger. Immunofluorescence microscopy analysis showed distinct subcellular localizations for the three isoforms: whereas ECE-1a and ECE-1c are localized at the cell surface, ECE-1b was found to be intracellular and showed significant co-localization with a marker protein for the trans-Golgi network. We determined that the three isoforms have similar kinetic rate constants (Km, kcat and Vmax) for the processing of big endothelin 1 and that the big endothelin isoforms 1, 2 and 3 are cleaved with similar relative velocities of 1.0:0.1:0.1 by the three isoenzymes. |
| Databáze: | OpenAIRE |
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