Pharmaceutical Sciences Faculty Publications
Phosphorylation of Ser24 in the Pleckstrin Homology Domain of Insulin Receptor Substrate-1 by Mouse Pelle-Like Kinase/Interleukin-1 Receptor-Associated Kinase: Cross-Talk Between Inflammatory Signaling and Insulin Signaling that May Contribute to Insulin Resistance
Document Type
Article
Publication Date
6-17-2005
Journal Title
The Journal of Biological Chemistry
ISSN
0021-9258
Volume
280
Issue
24
First Page
23173
Last Page
23183
DOI
10.1074/jbc.M501439200
PubMed ID
15849359
Abstract
Inflammation contributes to insulin resistance in diabetes and obesity. Mouse Pelle-like kinase (mPLK, homolog of human IL-1 receptor-associated kinase (IRAK)) participates in inflammatory signaling. We evaluated IRS-1 as a novel substrate for mPLK that may contribute to linking inflammation with insulin resistance. Wild-type mPLK, but not a kinase-inactive mutant (mPLK-KD), directly phosphorylated full-length IRS-1 in vitro. This in vitro phosphorylation was increased when mPLK was immunoprecipitated from tumor necrosis factor (TNF)-alpha-treated cells. In NIH-3T3(IR) cells, wild-type mPLK (but not mPLK-KD) co-immunoprecipitated with IRS-1. This association was increased by treatment of cells with TNF-alpha. Using mass spectrometry, we identified Ser(24) in the pleckstrin homology (PH) domain of IRS-1 as a specific phosphorylation site for mPLK. IRS-1 mutants S24D or S24E (mimicking phosphorylation at Ser(24)) had impaired ability to associate with insulin receptors resulting in diminished tyrosine phosphorylation of IRS-1 and impaired ability of IRS-1 to bind and activate PI-3 kinase in response to insulin. IRS-1-S24D also had an impaired ability to mediate insulin-stimulated translocation of GLUT4 in rat adipose cells. Importantly, endogenous mPLK/IRAK was activated in response to TNF-alpha or interleukin 1 treatment of primary adipose cells. In addition, using a phospho-specific antibody against IRS-1 phosphorylated at Ser(24), we found that interleukin-1 or TNF-alpha treatment of Fao cells stimulated increased phosphorylation of endogenous IRS-1 at Ser(24). We conclude that IRS-1 is a novel physiological substrate for mPLK. TNF-alpha-regulated phosphorylation at Ser(24) in the pleckstrin homology domain of IRS-1 by mPLK/IRAK represents an additional mechanism for cross-talk between inflammatory signaling and insulin signaling that may contribute to metabolic insulin resistance.
Keywords
Adipose tissue, blood proteins, cell line, glucose transporter type 4, glutathione transferase, immunoblotting, immunoprecipitation, inflammation, insulin, mass spectrometry, molecular, monosaccharide transport proteins, muscle proteins, mutation, phosphoproteins, phosphorylation, plasmids, Protein Binding, protein kinases, protein structure, tertiary, recombinant fusion proteins, serine, signal transduction, transfection, tumor necrosis factor-alpha
Recommended Citation
Kim, Jeong-a; Yeh, Deborah C.; Ver, Marel; Li, Yunhua; Carranza, Andrea; Conrads, Thomas P.; Veenstra, Timothy D.; Harrington, Maureen A.; and Quon, Michael J., "Phosphorylation of Ser24 in the Pleckstrin Homology Domain of Insulin Receptor Substrate-1 by Mouse Pelle-Like Kinase/Interleukin-1 Receptor-Associated Kinase: Cross-Talk Between Inflammatory Signaling and Insulin Signaling that May Contribute to Insulin Resistance" (2005). Pharmaceutical Sciences Faculty Publications. 428.
https://digitalcommons.cedarville.edu/pharmaceutical_sciences_publications/428