Publication Date:
1993-06-25
Description:
Insulin-induced activation of extracellular signal-regulated kinases [ERKs, also known as mitogen-activated protein (MAP) kinases] is mediated by Ras. Insulin activates Ras primarily by increasing the rate of guanine nucleotide-releasing activity. Here, we show that insulin-induced activation of ERKs was enhanced by stable overexpression of growth factor receptor-bound protein 2 (GRB2) but not by overexpression of GRB2 proteins with point mutations in the Src homology 2 and 3 domains. Moreover, a dominant negative form of Ras (with Ser17 substituted with Asn) blocked insulin-induced activation of ERKs in cells that overexpressed GRB2. GRB2 overexpression led to increased formation of a complex between the guanine nucleotide-releasing factor Sos (the product of the mammalian homolog of son of sevenless gene) and GRB2. In response to insulin stimulation, this complex bound to tyrosine-phosphorylated IRS-1 (insulin receptor substrate-1) and Shc. In contrast to the activated epidermal growth factor receptor that binds the GRB2-Sos complex directly, activation of the insulin receptor results in the interaction of GRB2-Sos with IRS-1 and Shc, thus linking the insulin receptor to Ras signaling pathways.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Skolnik, E Y -- Batzer, A -- Li, N -- Lee, C H -- Lowenstein, E -- Mohammadi, M -- Margolis, B -- Schlessinger, J -- DK01927/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1993 Jun 25;260(5116):1953-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, New York University Medical Center, NY 10016.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8316835" target="_blank"〉PubMed〈/a〉
Keywords:
*Adaptor Proteins, Signal Transducing
;
Amino Acid Sequence
;
Animals
;
Cell Line
;
Enzyme Activation
;
Epidermal Growth Factor/*metabolism
;
GRB2 Adaptor Protein
;
Insulin/pharmacology
;
Insulin Receptor Substrate Proteins
;
Membrane Proteins/metabolism
;
Mitogen-Activated Protein Kinase 1
;
Mitogen-Activated Protein Kinase 3
;
*Mitogen-Activated Protein Kinases
;
Molecular Sequence Data
;
Phosphoproteins/metabolism
;
Phosphorylation
;
Protein-Serine-Threonine Kinases/*metabolism
;
Proteins/*metabolism
;
Receptor, Insulin/*metabolism
;
Signal Transduction
;
Son of Sevenless Proteins
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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