G protein beta gamma subunits stimulate phosphorylation of Shc adapter protein.

Touhara, K

Hawes, BE

van Biesen, T

Lefkowitz, RJ

United States

2013-09-10T15:37:04Z

1995-09-26

The mechanism of mitogen-activated protein (MAP) kinase activation by pertussis toxin-sensitive Gi-coupled receptors is known to involve the beta gamma subunits of heterotrimeric G proteins (G beta gamma), p21ras activation, and an as-yet-unidentified tyrosine kinase. To investigate the mechanism of G beta gamma-stimulated p21ras activation, G beta gamma-mediated tyrosine phosphorylation was examined by overexpressing G beta gamma or alpha 2-C10 adrenergic receptors (ARs) that couple to Gi in COS-7 cells. Immunoprecipitation of phosphotyrosine-containing proteins revealed a 2- to 3-fold increase in the phosphorylation of two proteins of approximately 50 kDa (designated as p52) in G beta gamma-transfected cells or in alpha 2-C10 AR-transfected cells stimulated with the agonist UK-14304. The latter response was pertussis toxin sensitive. These proteins (p52) were also specifically immunoprecipitated with anti-Shc antibodies and comigrated with two Shc proteins, 46 and 52 kDa. The G beta gamma- or alpha 2-C10 AR-stimulated p52 (Shc) phosphorylation was inhibited by coexpression of the carboxyl terminus of beta-adrenergic receptor kinase (a G beta gamma-binding pleckstrin homology domain peptide) or by the tyrosine kinase inhibitors genistein and herbimycin A, but not by a dominant negative mutant of p21ras. Worthmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K) inhibited phosphorylation of p52 (Shc), implying involvement of PI3K. These results suggest that G beta gamma-stimulated Shc phosphorylation represents an early step in the pathway leading to p21ras activation, similar to the mechanism utilized by growth factor tyrosine kinase receptors.

http://www.ncbi.nlm.nih.gov/pubmed/7568118

0027-8424

https://hdl.handle.net/10161/7837

eng

Proceedings of the National Academy of Sciences

Proc Natl Acad Sci U S A

Adaptor Proteins, Signal Transducing

Adaptor Proteins, Vesicular Transport

Androstadienes

Animals

Benzoquinones

Calcium-Calmodulin-Dependent Protein Kinases

Cell Line

Cercopithecus aethiops

Enzyme Activation

Enzyme Inhibitors

GTP-Binding Proteins

Genistein

Humans

Isoflavones

Kidney

Kinetics

Lactams, Macrocyclic

Macromolecular Substances

Pertussis Toxin

Phosphates

Phosphatidylinositol 3-Kinases

Phosphorylation

Phosphotransferases (Alcohol Group Acceptor)

Protein-Tyrosine Kinases

Proteins

Proto-Oncogene Proteins p21(ras)

Quinones

Receptors, Adrenergic, alpha-2

Recombinant Proteins

Rifabutin

Shc Signaling Adaptor Proteins

Src Homology 2 Domain-Containing, Transforming Protein 1

Tetradecanoylphorbol Acetate

Transfection

Virulence Factors, Bordetella

G protein beta gamma subunits stimulate phosphorylation of Shc adapter protein.

Journal article

http://www.ncbi.nlm.nih.gov/pubmed/7568118

9284

9287

20

Basic Science Departments

Biochemistry

Chemistry

Clinical Science Departments

Duke

Duke Cancer Institute

Institutes and Centers

Medicine

Medicine, Cardiology

Pathology

School of Medicine

Trinity College of Arts & Sciences

Published

92