Publication Date:
2015-07-15
Description:
Insulin-induced gene 1 (Insig-1) and Insig-2 are endoplasmic reticulum membrane-embedded sterol sensors that regulate the cellular accumulation of sterols. Despite their physiological importance, the structural information on Insigs remains limited. Here we report the high-resolution structures of MvINS, an Insig homolog from Mycobacterium vanbaalenii. MvINS exists as a homotrimer. Each protomer comprises six transmembrane segments (TMs), with TM3 and TM4 contributing to homotrimerization. The six TMs enclose a V-shaped cavity that can accommodate a diacylglycerol molecule. A homology-based structural model of human Insig-2, together with biochemical characterizations, suggest that the central cavity of Insig-2 accommodates 25-hydroxycholesterol, whereas TM3 and TM4 engage in Scap binding. These analyses provide an important framework for further functional and mechanistic understanding of Insig proteins and the sterol regulatory element-binding protein pathway.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4704858/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4704858/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ren, Ruobing -- Zhou, Xinhui -- He, Yuan -- Ke, Meng -- Wu, Jianping -- Liu, Xiaohui -- Yan, Chuangye -- Wu, Yixuan -- Gong, Xin -- Lei, Xiaoguang -- Yan, S Frank -- Radhakrishnan, Arun -- Yan, Nieng -- HL-20948/HL/NHLBI NIH HHS/ -- P01 HL020948/HL/NHLBI NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2015 Jul 10;349(6244):187-91. doi: 10.1126/science.aab1091.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China. Center for Structural Biology, School of Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China. Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China. ; National Institute of Biological Sciences, Beijing 102206, China. ; Molecular Design and Chemical Biology, Therapeutic Modalities, Roche Pharma Research and Early Development, Roche Innovation Center Shanghai, Shanghai 201203, China. ; Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26160948" target="_blank"〉PubMed〈/a〉
Keywords:
Bacterial Proteins/*chemistry
;
Crystallography, X-Ray
;
Diglycerides/chemistry
;
Humans
;
Hydroxycholesterols/chemistry/*metabolism
;
Intracellular Signaling Peptides and Proteins/*chemistry
;
Membrane Proteins/*chemistry
;
Mycobacterium/*metabolism
;
Protein Multimerization
;
Protein Structure, Secondary
;
Sterol Regulatory Element Binding Proteins/*chemistry
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
