Integrin-linked tyrosine phosphorylation increases membrane association of protein kinase C alpha in pancreatic acinar cells.
Ligation of beta 1 integrin receptors resulted in increased tyrosine phosphorylation of at least five proteins (Mrest = 110, 85, 55, 30 and 24 kD) from rat pancreatic acinar cells. Increased protein kinase C (PKC) activity and elevated amounts of immunoreactive PKC alpha were demonstrated in membrane fractions from integrin-ligated acinar cells. Membrane translocation of PKC alpha was confirmed using scanning confocal laser microscopy in immunocytochemical preparations of acinar cells following beta 1 integrin ligation. These studies establish the presence of a beta 1 integrin-linked protein tyrosine phosphorylation system in exocrine pancreatic cells and provide evidence for integrative activity of this system with PKC, a primary signalling pathway of central importance in these cells.
Wrenn
R W
RW
School of Medicine, Medical College of Georgia, Augusta 30912-2000.
Herman
L E
LE
D000818:Animals; D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D019012:Integrin beta1; D016023:Integrins / Q000378:metabolism*; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D010179:Pancreas / Q000201:enzymology*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011493:Protein Kinase C / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism
D019012:Integrin beta1; D016023:Integrins; D007527:Isoenzymes; D010750:Phosphoproteins; D019000:Phosphotyrosine; D014443:Tyrosine; D011493:Protein Kinase C