TY - JOUR
T1 - Tyrosine phosphorylation is a signal for the trafficking of pp85, an 85-kDa phosphorylated polypeptide associated with phosphatidylinositol kinase activity
AU - Cohen, Bruce
AU - Yoakim, Monique
AU - Piwnica-Worms, Helen
AU - Roberts, Thomas M.
AU - Schaffhausen, Brian S.
PY - 1990
Y1 - 1990
N2 - A family of 85/86-kDa (85K/86K) polypeptides closely linked to phosphatidylinositol kinase activity is found in polyoma middle-sized tumor antigen (MTAg)/ pp60c-src complexes. MTAg and the 85-kDa phosphoprotein (pp85) could be reassociated in solution, or on blots, after denaturation with SDS. Results from such experiments focus attention on phosphorylation in controlling intracellular sorting and activation of pp85. Tyrosine phosphorylation seems important for recruitment of pp85 from cytosol to membrane. By blotting, pp85 is substantially cytosolic, whereas that recognized by anti-phosphotyrosine antibody is almost exclusively in membranes. Tyrosine phosphorylation also determines association of pp85 with MTAg. Manipulation of MTAg tyrosine phosphorylation, for example, by expressing MTAg using baculovirus vectors in the absence or presence of pp60c-src, dramatically affects reassociation. Finally, tyrosine phosphorylation appears to be involved in release of pp85 from MTAg, since vanadate increased its rate of dissociation.
AB - A family of 85/86-kDa (85K/86K) polypeptides closely linked to phosphatidylinositol kinase activity is found in polyoma middle-sized tumor antigen (MTAg)/ pp60c-src complexes. MTAg and the 85-kDa phosphoprotein (pp85) could be reassociated in solution, or on blots, after denaturation with SDS. Results from such experiments focus attention on phosphorylation in controlling intracellular sorting and activation of pp85. Tyrosine phosphorylation seems important for recruitment of pp85 from cytosol to membrane. By blotting, pp85 is substantially cytosolic, whereas that recognized by anti-phosphotyrosine antibody is almost exclusively in membranes. Tyrosine phosphorylation also determines association of pp85 with MTAg. Manipulation of MTAg tyrosine phosphorylation, for example, by expressing MTAg using baculovirus vectors in the absence or presence of pp60c-src, dramatically affects reassociation. Finally, tyrosine phosphorylation appears to be involved in release of pp85 from MTAg, since vanadate increased its rate of dissociation.
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U2 - 10.1073/pnas.87.12.4458
DO - 10.1073/pnas.87.12.4458
M3 - Article
C2 - 1693771
AN - SCOPUS:0025315794
SN - 0027-8424
VL - 87
SP - 4458
EP - 4462
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 12
ER -