Insulin receptor substrate-1 (IRS-1) forms a ribonucleoprotein complex associated with polysomes

• Published in: FEBS letters 2013-08, Vol.587 (15), p.2319-2324
• Main Authors: Ozoe, Atsufumi, Sone, Meri, Fukushima, Toshiaki, Kataoka, Naoyuki, Arai, Toshiya, Chida, Kazuhiro, Asano, Tomoichiro, Hakuno, Fumihiko, Takahashi, Shin-Ichiro
• Format: Article
• Language: English
• Subjects: 4E binding proteins; 4EBPs; blue native-polyacrylamide gel electrophoresis; BN-PAGE; Cell Proliferation; DMEM; Dulbecco's modified Eagle's medium; eIF; EJC; eukaryotic initiation factor; exon junction complex; FBS; fetal bovine serum; HEK293; human embryonic kidney 293; Humans; IGFs; Insulin receptor substrate; Insulin Receptor Substrate Proteins - metabolism; insulin receptor substrates; Insulin-like growth factor-I (IGF-I); insulin-like growth factors; IRSs; MALDI-TOF-MS; mammalian target of rapamycin; MAPK; matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry; MCF-7 Cells; messenger ribonucleoprotein; messenger RNA; mitogen-activated protein kinase; mRNA; mRNP; mTOR; PABPC1; phosphatidylinositol 3-kinase; PI3K; PIC; poly(A) binding protein cytoplasmic 1; Polyribosomes - metabolism; Protein Binding; ribonuclease A; Ribonucleoproteins - metabolism; ribosomal subunit protein S6; RNA; RNase A; rpS6; S6 protein kinases; S6Ks; Translation; translation preinitiation complex
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2013.05.066

•IRS-1 forms complexes with messenger RNA.•IRS-1 interacts with PABPC1, eIF4E and eIF4G in RNA-dependent manner.•IRS-1 is distributed into high-density fractions containing polysomes in proliferating cells. Insulin receptor substrates (IRSs) are known to play important roles in mediating intracellular insulin-like growth factors (IGFs)/insulin signaling. In this study, we identified components of messenger ribonucleoprotein (mRNP) as IRS-1-associated proteins. IRS-1 complex formation analysis revealed that IRS-1 is incorporated into the complexes of molecular mass more than 1000kDa, which were disrupted by treatment with RNase. Furthermore, oligo(dT) beads precipitated IRS-1 from cell lysates, showing that the IRS-1 complexes contained messenger RNA. Taken together with the data that IRS-1 was fractionated into the polysome-containing high-density fractions, we concluded that IRS-1 forms the novel complexes with mRNPs. IRS1physically interactswithPABPC1byanti bait coimmunoprecipitation(View Interaction:1,2) IRS1physically interactswithPABPC1byanti tag coimmunoprecipitation(View interaction) IRS1physically interactswithPABPC1byanti bait coimmunoprecipitation(View interaction) IRS1physically interactswithEIF4FandPABPC1byanti bait coimmunoprecipitation(View interaction)