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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  1. Joan Massague
    389 Massague