Regulation of membrane-type-1 matrix metalloproteinase activity by its cytoplasmic domain
| Autor: | Sara A. Wickström, Jouko Lohi, Heli Valtanen, Jorma Keski-Oja, Kaisa Lehti |
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| Rok vydání: | 2000 |
| Předmět: |
Cytoplasm
Matrix Metalloproteinases Membrane-Associated Cell Gelatinase A Biology Cleavage (embryo) Transfection Biochemistry 03 medical and health sciences 0302 clinical medicine medicine Tumor Cells Cultured Gelatinase Humans Neoplasm Invasiveness Protease Inhibitors Cloning Molecular Molecular Biology Melanoma 030304 developmental biology Sequence Deletion 0303 health sciences Matrigel Wild type Metalloendopeptidases Cell Biology Molecular biology Transmembrane protein Recombinant Proteins Cell biology Enzyme Activation Drug Combinations medicine.anatomical_structure 030220 oncology & carcinogenesis Matrix Metalloproteinase 2 Proteoglycans Collagen Laminin |
| Zdroj: | Karolinska Institutet |
| ISSN: | 0021-9258 |
| Popis: | Membrane-type-1 matrix metalloproteinase (MT1-MMP) has transmembrane and cytoplasmic domains, which target it to invasive fronts. We analyzed the role of the cytoplasmic tail by expressing wild type MT1-MMP and three mutants with progressively truncated C termini in human Bowes melanoma cells. We examined gelatinase A activation and the localization and processing of recombinant proteins in stable cell clones using gelatin zymography, immunoblotting, and immunofluorescence. Cell invasion was analyzed in vitro by Matrigel invasion assays. Gelatinase A was activated in all cell clones. However, the localization of MT1-MMP to the leading edge of migrating cells and cell invasion through Matrigel were strongly enhanced only in cells expressing either wild type or truncated MT1-MMP lacking 6 C-terminal amino acid residues (Delta577). Truncations of 10 or 16 amino acid residues in the cytoplasmic domain (Delta567 and Delta573, respectively) disturbed MT1-MMP localization. The expression of wild type and Delta577 MT1-MMPs induced also their cleavage to 43-kDa cell surface forms and the release of soluble, approximately 20-kDa N-terminal fragments containing the catalytic center. A synthetic MMP inhibitor but not a gelatinase inhibitor prevented the processing, suggesting that autocatalytic cleavage occurs. Purified soluble MT1-MMP was also autoproteolytically processed to 43- and 20-kDa forms in vitro. Our results indicate that the cytoplasmic domain has an important role in cell invasion by controlling both the targeting and degradation/turnover of MT1-MMP. |
| Databáze: | OpenAIRE |
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