PYK2 as a mediator of endothelin-1/G alpha 11 signaling to GLUT4 glucose transporters
Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology
3T3 Cells; Animals; Endothelin-1; Focal Adhesion Kinase 2; GTP-Binding Protein alpha Subunits, Gq-G11; Glucose Transporter Type 4; Heterotrimeric GTP-Binding Proteins; Mice; Microscopy, Fluorescence; Monosaccharide Transport Proteins; *Muscle Proteins; Protein Transport; Protein-Tyrosine Kinases; Signal Transduction
Life Sciences | Medicine and Health Sciences
Endothelin-1 (ET-1) signaling through G alpha(q/11) stimulates translocation of intracellular GLUT4 glucose transporters to the plasma membrane of 3T3-L1 adipocytes by an unknown mechanism that requires protein tyrosine phosphorylation and ADP-ribosylation factor 6 (ARF6) but is independent of phosphatidylinositol 3 (PI3)-kinase. In contrast, insulin action on this process requires PI3-kinase but not ARF6. Here we report the identification of two proteins selectively tyrosine-phosphorylated in response to ET-1 but not insulin: the Ca(2+)-activated tyrosine kinase PYK2 and its physiological substrate, the adhesion scaffold protein paxillin. Endogenous paxillin as well as expressed Myc-tagged PYK2 or a Myc-tagged kinase-deficient PYK2 protein were acutely directed to F-actin-rich adhesion sites from the adipocyte cytoplasm in response to ET-1 but not insulin. CADTK-related non-kinase (CRNK) is a dominant negative form of PYK2 containing the C-terminal portion of the protein, which binds paxillin but lacks the PYK2 autophosphorylation site (Tyr(402)). CRNK expression in 3T3-L1 adipocytes inhibited ET-1-mediated F-actin polymerization and translocation of Myc-tagged GLUT4-enhanced green fluorescent protein (EGFP) to the plasma membrane without disrupting insulin action on these processes. These data reveal the tyrosine kinase PYK2 as a required signaling element in the regulation of GLUT4 recycling in 3T3-L1 adipocytes by ET-1, whereas insulin signaling is directed through a different pathway.
DOI of Published Version
J Biol Chem. 2001 Dec 21;276(51):47751-4. Epub 2001 Oct 15. Link to article on publisher's site
The Journal of biological chemistry
Park, Jin Gyoon; Bose, Avirup; Leszyk, John D.; and Czech, Michael P., "PYK2 as a mediator of endothelin-1/G alpha 11 signaling to GLUT4 glucose transporters" (2001). Open Access Articles. 734.