Journal: Nature Communications
Article Title: Mitotic regulators and the SHP2-MAPK pathway promote IR endocytosis and feedback regulation of insulin signaling
doi: 10.1038/s41467-019-09318-3
Figure Lengend Snippet: IRS1/2 are required for insulin-activated IR endocytosis. a HepG2 cells stably expressing IR-GFP WT were transfected with the indicated siRNAs or siRNA-resistant Myc-IRS1, serum starved, treated without or with 100 nM insulin for 5 min, and stained with anti-GFP antibodies. b Quantification of the ratios of PM and IC IR-GFP signals of cells in a (siLUC, n = 26; siLUC + Ins, n = 42; si-IRS1, n = 41; si-IRS1, n = 26; si-IRS2, n = 20; si-IRS2 + Ins, n = 10; si-IRS1/2, n = 48, si-IRS1/2 + Ins, n = 66; si-IRS1/2 + IRS1, n = 14; si-IRS1/2 + IRS1 + Ins, n = 14; mean ± s.d.; **** p < 0.0001; two-tailed unpaired t test). c Domains and YXXΦ motifs of human IRS1 and mouse IRS2. PH, pleckstrin homology domain; PTB, phosphotyrosine-binding domain. AP2M1- and SHP2-binding regions are indicated. YXXΦ motifs and phosphotyrosine sites of IR for SHP2 binding are shown as blue and red bars, respectively. The MAPK phosphorylation sites are labeled as green letters in the sequences. d 293FT cells stably expressing IR-GFP WT were transfected with the indicated siRNAs or siRNA-resistant Myc-IRS1, serum starved, treated without or with 100 nM insulin for 5 min, and stained with anti-GFP (IR; green), anti-Myc (IRS1; red), and DAPI (blue) (3YA, the IRS1 Y612A/Y632A/Y662A triple mutant; 3YF, the Y612F/Y632F/Y662F triple mutant; 3SA, the S616A/S636A/S666A triple mutant; 3SD, the S616D/S636D/S666D triple mutant; 2YA, the Y1179A/Y1229A double mutant). Scale bar, 5 µm. e Quantification of the ratios of PM and IC IR-GFP signals of cells in d (siLUC, n = 49; siLUC + Ins, n = 87; si-IRS1/2, n = 46; si-IRS1/2 + Ins, n = 87; si-IRS1/2 + WT, n = 65; si-IRS1/2 + WT + Ins, n = 112; si-IRS1/2 + 3YA, n = 54; si-IRS1/2 + 3YA + Ins, n = 63, si-IRS1/2 + 3SA, n = 40; si-IRS1/2 + 3SA + Ins, n = 66; si-IRS1/2 + 3 SD, n = 42; si-IRS1/2 + 3 SD + Ins, n = 63; si-IRS1/2 + 3YF, n = 48; si-IRS1/2 + 3YF + Ins, n = 58; si-IRS1/2 + Y612A, n = 48; si-IRS1/2 + Y612A, n = 58; si-IRS1/2 + 1–864, n = 23; si-IRS1/2 + 1–864 + Ins, n = 35; si-IRS1/2 + 2YA, n = 28, si-IRS1/2 + 2YA + Ins, n = 42; mean ± s.d.; **** p < 0.0001; two-tailed unpaired t test). f 293FT cells were serum starved and treated without or with 100 nM insulin for 5 min. Total cell lysate (TCL), anti-IRS1 IP, and IgG IP were blotted with anti-IRS1 and anti-AP2B1 antibodies. g Serum-starved primary hepatocytes were treated with DMSO or 10 µM SHP099 for 2 h and treated with 100 nM insulin for 5 min. TCL, anti-IRS1 IP were blotted with anti-IRS1 and anti-AP2B1 antibodies. Source data are provided as a Source Data file
Article Snippet: Active SHP2 (2.9 μM, SignalChem) diluted in the phosphatase dilution buffer [50 mM imidazole, pH 7.2, 0.2% 2-mercaptoethanol, and 65 ng μl −1 BSA] was incubated with IRS1 peptides (2.6 mM) at 37 °C for the indicated time points.
Techniques: Stable Transfection, Expressing, Transfection, Staining, Two Tailed Test, Binding Assay, Phospho-proteomics, Labeling, Mutagenesis