Spatiotemporal regulation of insulin signaling by liquid–liquid phase separation

• DOI: 10.1038/s41421-022-00430-1
• Publication Date: 2022-07-05T12:03:14Z
• Authors: Kun Zhou; Qiaoli Chen; Jiamou Chen; Derong Liang; Weikuan Feng; Minjun Liu; Qi Wang; Ruizhen Wang; Qian Ouyang; Chao Quan; Shuai Chen
• Keywords: 0301 basic medicine; 03 medical and health sciences; QH573-671; Cytology; Article

AbstractInsulin signals through its receptor to recruit insulin receptor substrates (IRS) and phosphatidylinositol 3-kinase (PI3K) to the plasma membrane for production of phosphatidylinositol-3,4,5-trisphosphate (PIP3) from phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], which consequently activates protein kinase B (PKB). How insulin signals transduce from the plasma membrane into the cytoplasm is not clearly understood. Here we show that liquid–liquid phase separation (LLPS) plays a critical role in spatiotemporal control of insulin signaling through regulating multiple components including IRS1. Both protein concentration and insulin stimulation can drive the formation of intracellular IRS1 condensates through LLPS. Components including PI(4,5)P2, p85-PI3K and PDK1 are constitutively present in IRS1 condensates whereas production of PIP3 and recruitment of PKB in them are induced by insulin. Thus, IRS1 condensates function as intracellular signal hubs to mediate insulin signaling, whose formation is impaired in insulin resistant cells. Collectively, these data reveal an important function of LLPS in spatiotemporal control of insulin signaling.