Positive and Negative Regulatory Role of Insulin Receptor Substrate 1 and 2 (IRS-1 and IRS-2) Serine/Threonine Phosphorylation

Biochemistry ◽  
2002 ◽  
Vol 41 (22) ◽  
pp. 7082-7091 ◽  
Author(s):  
Michael W. Greene ◽  
Robert S. Garofalo
Keyword(s):  
Insulin Receptor ◽  
Regulatory Role ◽  
Insulin Receptor Substrate ◽  
Insulin Receptor Substrate 1 ◽  
Negative Regulatory Role

scholarly journals Gly972Arg Variant of Insulin Receptor Substrate 1 Gene and Colorectal Cancer Risk in Overweight/Obese Subjects

2016 ◽  
Vol 31 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Touraj Mahmoudi ◽  
Keivan Majidzadeh-A ◽  
Khatoon Karimi ◽  
Hamid Farahani ◽  
Reza Dabiri ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Insulin Receptor ◽  
Case Control Study ◽  
Insulin Receptor Substrate ◽  
Protective Effects ◽  
Insulin Receptor Substrate 1 ◽  
Pcr Rflp ◽  
Obese Subjects ◽  
Control Study

Background Given the major role of obesity and insulin resistance (IR) in colorectal cancer (CRC), we investigated whether genetic variants in ghrelin ( GHRL), resistin ( RETN) and insulin receptor substrate 1 ( IRS1) were associated with CRC risk. Methods This study was conducted as a case-control study, and 750 subjects, including 438 controls and 312 patients with CRC, were enrolled and genotyped using the PCR-RFLP method. Results No significant differences were observed for GHRL (rs696217), RETN (rs3745367) and IRS1 (rs1801278, Gly972Arg or G972R) gene variants between the cases and controls. However, the IRS1 G972R R allele compared with the G allele and the G972R RR+GR genotype compared with the GG genotype appeared to be markers of decreased CRC susceptibility in the overweight/obese subjects (p = 0.024; odds ratio [OR] = 0.42, 95% confidence interval [95% CI], 0.20-0.91; and p = 0.048; OR = 0.42, 95% CI, 0.17-0.99, respectively). Furthermore, the R allele and RR+GR genotype were also associated with decreased risks for obesity in the patients with CRC (p = 0.007; OR = 0.35, 95% CI, 0.15-0.77; and p = 0.015; OR = 0.35, 95% CI, 0.15-0.72, respectively). Conclusions In accordance with previous studies, our findings suggest that the IRS1 G972R R allele and RR+GR genotype have protective effects for CRC in overweight/obese patients and for obesity in patients with CRC. Nevertheless, further studies are required to confirm these findings.

14-3-3 Facilitates Insulin-Stimulated Intracellular Trafficking of Insulin Receptor Substrate 1

2002 ◽  
Vol 16 (3) ◽  
pp. 552-562 ◽  
Author(s):  
Xiaoqin Xiang ◽  
Mingsheng Yuan ◽  
Ying Song ◽  
Neil Ruderman ◽  
Rong Wen ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Intracellular Trafficking ◽  
High Speed ◽  
Insulin Treatment ◽  
Insulin Receptor Substrate ◽  
Insulin Receptor Substrate 1 ◽  
Integral Role ◽  
Endogenous Proteins

Abstract The appearance of a complex between tyrosine-phosphorylated insulin receptor substrate 1 (IRS-1) and PI3K in a high-speed pellet fraction (HSP) is thought to be a key event in insulin action. Conversely, the disappearance of the IRS-1/PI3K complex from this fraction has been linked to insulin desensitization. The present study examines the role of 14-3-3, a specific phospho-serine binding protein, in mediating the disappearance of IRS-1 from the HSP after insulin treatment. An in vitro pull-down assay using recombinant 14-3-3 revealed that insulin enhances the association of 14-3-3 with IRS-1 in cultured adipocytes and that this is completely inhibited by wortmannin. An association of IRS-1 and 14-3-3 was also observed and was maximal after stimulation by insulin, when endogenous proteins were immunoprecipitated. Epidermal growth factor (EGF), 12-O-tetradecanoylphorbol-13-acetate, and okadaic acid, other agents that cause serine/threonine phosphorylation of IRS-1, also stimulated IRS binding to 14-3-3. The enhancement of IRS-1 binding to 14-3-3 by insulin was accompanied by movement of IRS-1 and the p85 subunit of PI3K from the HSP to the cytosol. In keeping with a key role of 14-3-3 in mediating this redistribution of IRS-1, the complexes of IRS-1 and 14-3-3 were found in the cytosol but not in the HSP of insulin-treated cells. In addition, colocalization of IRS-1 and 14-3-3 was observed in the cytoplasm after insulin treatment by confocal microscopy. Finally, the addition of a phosphorylated 14-3-3 binding peptide to an adipocyte homogenate (to remove 14-3-3 from IRS-1) increased the abundance of IRS-1/PI3K complexes in the HSP and decreased their abundance in the cytosol. These findings strongly suggest that 14-3-3 participates in the intracellular trafficking of IRS-1 by promoting the displacement of serine-phosphorylated IRS-1 from particular structures. They also suggest that 14-3-3 proteins could play an integral role in the process of insulin desensitization.

scholarly journals Role of the Insulin-Like Growth Factor I/Insulin Receptor Substrate 1 Axis in Rad51 Trafficking and DNA Repair by Homologous Recombination

2003 ◽  
Vol 23 (21) ◽  
pp. 7510-7524 ◽  
Author(s):  
Joanna Trojanek ◽  
Thu Ho ◽  
Luis Del Valle ◽  
Michal Nowicki ◽  
Jin Ying Wang ◽  
...  
Keyword(s):  
Dna Repair ◽  
Growth Factor ◽  
Homologous Recombination ◽  
Insulin Receptor ◽  
Insulin Receptor Substrate ◽  
Insulin Like Growth Factor ◽  
Insulin Receptor Substrate 1 ◽  
Factor I ◽  
Igf I

ABSTRACT The receptor for insulin-like growth factor I (IGF-IR) controls normal and pathological growth of cells. DNA repair pathways represent an unexplored target through which the IGF-IR signaling system might support pathological growth leading to cellular transformation. However, this study demonstrates that IGF-I stimulation supports homologous recombination-directed DNA repair (HRR). This effect involves an interaction between Rad51 and the major IGF-IR signaling molecule, insulin receptor substrate 1 (IRS-1). The binding occurs within the cytoplasm, engages the N-terminal domain of IRS-1, and is attenuated by IGF-I-mediated IRS-1 tyrosine phosphorylation. In the absence of IGF-I stimulation, or if mutated IGF-IR fails to phosphorylate IRS-1, localization of Rad51 to the sites of damaged DNA is diminished. These results point to a direct role of IRS-1 in HRR and suggest a novel role for the IGF-IR/IRS-1 axis in supporting the stability of the genome.

scholarly journals Role of Insulin Receptor Substrate-1 and pp60 in the Regulation of Insulin-induced Glucose Transport and GLUT4 Translocation in Primary Adipocytes

1997 ◽  
Vol 272 (41) ◽  
pp. 25839-25844 ◽  
Author(s):  
Yasushi Kaburagi ◽  
Shinobu Satoh ◽  
Hiroyuki Tamemoto ◽  
Ritsuko Yamamoto-Honda ◽  
Kazuyuki Tobe ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Glucose Transport ◽  
Insulin Receptor Substrate ◽  
Glut4 Translocation ◽  
Insulin Receptor Substrate 1

scholarly journals Essential Role of Insulin Receptor Substrate 1 (IRS-1) and IRS-2 in Adipocyte Differentiation

2001 ◽  
Vol 21 (7) ◽  
pp. 2521-2532 ◽  
Author(s):  
Hiroshi Miki ◽  
Toshimasa Yamauchi ◽  
Ryo Suzuki ◽  
Kajuro Komeda ◽  
Atsuko Tsuchida ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Adipocyte Differentiation ◽  
Kinase Inhibitor ◽  
Binding Protein ◽  
Insulin Receptor Substrate ◽  
Wild Type ◽  
Double Knockout ◽  
Insulin Receptor Substrate 1 ◽  
Fatty Acid Binding

ABSTRACT To investigate the role of insulin receptor substrate 1 (IRS-1) and IRS-2, the two ubiquitously expressed IRS proteins, in adipocyte differentiation, we established embryonic fibroblast cells with four different genotypes, i.e., wild-type, IRS-1 deficient (IRS-1−/−), IRS-2 deficient (IRS-2−/−), and IRS-1 IRS-2 double deficient (IRS-1−/−IRS-2−/−), from mouse embryos of the corresponding genotypes. The abilities of IRS-1−/− cells and IRS-2−/− cells to differentiate into adipocytes are approximately 60 and 15%, respectively, lower than that of wild-type cells, at day 8 after induction and, surprisingly, IRS-1−/− IRS-2−/− cells have no ability to differentiate into adipocytes. The expression of CCAAT/enhancer binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ) is severely decreased in IRS-1−/−IRS-2−/− cells at both the mRNA and the protein level, and the mRNAs of lipoprotein lipase and adipocyte fatty acid binding protein are severely decreased in IRS-1−/−IRS-2−/− cells. Phosphatidylinositol 3-kinase (PI 3-kinase) activity that increases during adipocyte differentiation is almost completely abolished in IRS-1−/−IRS-2−/− cells. Treatment of wild-type cells with a PI 3-kinase inhibitor, LY294002, markedly decreases the expression of C/EBPα and PPARγ, a result which is associated with a complete block of adipocyte differentiation. Moreover, histologic analysis of IRS-1−/− IRS-2−/− double-knockout mice 8 h after birth reveals severe reduction in white adipose tissue mass. Our results suggest that IRS-1 and IRS-2 play a crucial role in the upregulation of the C/EBPα and PPARγ expression and adipocyte differentiation.

The role of the NPXY motif in the insulin receptor in tyrosine phosphorylation of insulin receptor substrate-1 and Shc.

Endocrinology ◽  
1995 ◽  
Vol 136 (8) ◽  
pp. 3437-3443 ◽  
Author(s):  
Y Kaburagi ◽  
R Yamamoto-Honda ◽  
K Tobe ◽  
K Ueki ◽  
M Yachi ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Insulin Receptor Substrate ◽  
Insulin Receptor Substrate 1 ◽  
Npxy Motif
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