Activated release of membrane-anchored TGF-α in the absence of cytosol Journal Article
| Authors: | Bosenberg, M. W.; Pandiella, A.; Massagué, J. |
| Article Title: | Activated release of membrane-anchored TGF-α in the absence of cytosol |
| Abstract: | The ectodomain of proTGF-α, a membrane-anchored growth factor, is converted into soluble TGF-α by a regulated cellular proteolytic system that recognizes proTGF-α via the C-terminal valine of its cytoplasmic tail. In order to define the biochemical components involved in proTGF-α cleavage, we have used cells permeabilized with streptolysin O (SLO) that have been extensively washed to remove cytosol. PMA, acting through a Ca2+- independent protein kinase C, activates cleavage as efficiently in permeabilized cells as it does in intact cells. ProTGF-α cleavage is also stimulated by GTPγS through a mechanism whose pharmacological properties suggest the involvement of a heterotrimeric G protein acting upstream of the PMA-sensitive Ca2+-independent protein kinase C. Activated proTGF-α cleavage is dependent on ATP hydrolysis, appears not to require vesicular traffic, and acts specifically on proTGF-α that has reached the cell surface. These results indicate that proTGF-α is cleaved from the cell surface by a regulated system whose signaling, recognition, and proteolytic components are retained in cells devoid of cytosol. |
| Keywords: | signal transduction; transforming growth factor beta; carboxy terminal sequence; protein degradation; enzyme activity; molecular recognition; membrane protein; protein kinase c; cell adhesion; guanine nucleotide binding protein; cytosol; cell surface receptor; cho cell; protein precursor; priority journal; article; streptolysin o |
| Journal Title: | Journal of Cell Biology |
| Volume: | 122 |
| Issue: | 1 |
| ISSN: | 0021-9525 |
| Publisher: | Rockefeller University Press |
| Date Published: | 1993-07-01 |
| Start Page: | 95 |
| End Page: | 101 |
| Language: | English |
| DOI: | 10.1083/jcb.122.1.95 |
| PUBMED: | 8314849 |
| PROVIDER: | scopus |
| PMCID: | PMC2119606 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 1 March 2019 -- Source: Scopus |
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