Detection of Human Phospho-IRS1 (Y1179) by Western Blot. Western blot shows lysates of MCF‑7 human breast cancer cell line untreated|
(-) or treated (+) with 1 µg/mL Insulin for 5 minutes and 300 U/mL CIP for 1 hour. PVDF membrane was probed with 1 µg/mL of Mouse Anti-Human Phospho-IRS1 (Y1179) Monoclonal Antibody (Catalog # MAB7455) followed by HRP-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # HAF018). A specific band was detected for Phospho-IRS1 (Y1179) at approximately 150 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.
|Phospho-IRS1 (Y1179) in MCF‑7 Human Cell Line. IRS1 phosphorylated at Y1179 was detected in immersion fixed MCF‑7 human breast cancer cell line using Mouse Anti-Human Phospho-IRS1 (Y1179) Monoclonal Antibody (Catalog # MAB7455) at 25 µg/mL for 3 hours at room temperature. Cells were stained using the NorthernLights™ 557-conjugated Anti-Mouse IgG Secondary Antibody (red; Catalog # NL007) and counterstained with DAPI (blue). Specific staining was localized to cytoplasm. View our protocol for Fluorescent ICC Staining of Cells on Coverslips.|
Human IRS1 (insulin receptor substrate 1) is a 160-180 kDa substrate intermediate between the insulin and IGF-I receptor, and downstream signaling modulators. Upon insulin/IGF-I receptor activation, IRS1 is tyrosine phosphorylated, allowing its association with PI-3 kinase and GRB2. Human IRS1 is 1242 amino acids (aa) in length. It contains a PH (pleckstrin homology) domain (aa 12-115), followed by a PTB (phosphotyrosine-binding) domain (aa 160-263) and ten PEST (Pro/Glu/Ser/Thr) regions (aa 340-1225). IRS1 may be proteolytically cleaved at Arg656-Val657, generating a 90 kDa and 79 kDa fragment. Insulin receptor-mediated phosphorylation of human IRS1 on Y1179, or its murine equivalent, Y1172, mediates IRS-1 interaction with SH2 domains such as that of the Src family kinase, Fyn, or the tyrosine phosphatase, SHP-2.