ジャーナル: Science / 年: 2021 タイトル: A structure of human Scap bound to Insig-2 suggests how their interaction is regulated by sterols. 著者: Renhong Yan / Pingping Cao / Wenqi Song / Hongwu Qian / Ximing Du / Hudson W Coates / Xin Zhao / Yaning Li / Shuai Gao / Xin Gong / Ximing Liu / Jianhua Sui / Jianlin Lei / Hongyuan Yang / ...著者: Renhong Yan / Pingping Cao / Wenqi Song / Hongwu Qian / Ximing Du / Hudson W Coates / Xin Zhao / Yaning Li / Shuai Gao / Xin Gong / Ximing Liu / Jianhua Sui / Jianlin Lei / Hongyuan Yang / Andrew J Brown / Qiang Zhou / Chuangye Yan / Nieng Yan / 要旨: The sterol regulatory element-binding protein (SREBP) pathway controls cellular homeostasis of sterols. The key players in this pathway, Scap and Insig-1 and -2, are membrane-embedded sterol sensors. ...The sterol regulatory element-binding protein (SREBP) pathway controls cellular homeostasis of sterols. The key players in this pathway, Scap and Insig-1 and -2, are membrane-embedded sterol sensors. The 25-hydroxycholesterol (25HC)-dependent association of Scap and Insig acts as the master switch for the SREBP pathway. Here, we present cryo-electron microscopy analysis of the human Scap and Insig-2 complex in the presence of 25HC, with the transmembrane (TM) domains determined at an average resolution of 3.7 angstrom. The sterol-sensing domain in Scap and all six TMs in Insig-2 were resolved. A 25HC molecule is sandwiched between the S4 to S6 segments in Scap and TMs 3 and 4 in Insig-2 in the luminal leaflet of the membrane. Unwinding of the middle of the Scap-S4 segment is crucial for 25HC binding and Insig association.
A: Insulin-induced gene 2 protein B: Sterol regulatory element-binding protein cleavage-activating protein,Sterol regulatory element-binding protein cleavage-activating protein ヘテロ分子
Sterolregulatoryelement-bindingproteincleavage-activatingprotein,Sterolregulatoryelement-bindingproteincleavage-activatingprotein / SREBP cleavage-activating protein