Three mutations in sterol-sensing domain of SCAP block interaction with Insig and render SREBP cleavage insensitive to sterols Export

@article{citeulike:5776839, abstract = {We report the isolation and characterization of a new line of mutant Chinese hamster ovary cells, designated SRD-5, that are resistant to 25HC, a potent suppressor of cleavage of sterol regulatory element-binding proteins (SREBPs) in mammalian cells. In SRD-5 cells, SREBPs are cleaved constitutively, generating transcriptionally active nuclear SREBP even in the presence of sterols. Sequence analysis of SREBP cleavage-activating protein (SCAP) transcripts from SRD-5 cells revealed the presence of a mutation in one SCAP allele that results in substitution of a conserved Leu by Phe at amino acid 315 within the sterol-sensing domain. Sterols fail to inhibit the packaging of SREBP/SCAP(L315F) complexes into budding vesicles . Sterols also fail to induce binding of SCAP(L315F) to insig-1 or insig-2, two proteins that function in the sterol-mediated retention of SREBP/SCAP complexes in the endoplasmic reticulum. Similar findings were observed for SCAP(D443N) and SCAP(Y298C), both of which cause a sterol-resistant phenotype. Thus, three different point mutations, each within the sterol-sensing domain of SCAP, prevent sterol-induced binding of SCAP to insig proteins and abolish feedback regulation of SREBP processing by sterols.}, author = {Yabe, Daisuke and Xia, Zong-Ping and Adams, Christopher M. and Rawson, Robert B.}, citeulike-article-id = {5776839}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.262669399}, citeulike-linkout-1 = {http://www.pnas.org/content/99/26/16672.abstract}, citeulike-linkout-2 = {http://www.pnas.org/content/99/26/16672.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/12482938}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=12482938}, day = {24}, doi = {10.1073/pnas.262669399}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, keywords = {insig, mutation, scap, sensing, srebp, sterol}, month = {December}, number = {26}, pages = {16672--16677}, posted-at = {2009-09-11 20:18:41}, priority = {2}, title = {Three mutations in sterol-sensing domain of {SCAP} block interaction with {I}nsig and render {SREBP} cleavage insensitive to sterols}, url = {http://dx.doi.org/10.1073/pnas.262669399}, volume = {99}, year = {2002} }

TY - JOUR ID - citeulike:5776839 L3 - citeulike-article-id:5776839 N2 - We report the isolation and characterization of a new line of mutant Chinese hamster ovary cells, designated SRD-5, that are resistant to 25HC, a potent suppressor of cleavage of sterol regulatory element-binding proteins (SREBPs) in mammalian cells. In SRD-5 cells, SREBPs are cleaved constitutively, generating transcriptionally active nuclear SREBP even in the presence of sterols. Sequence analysis of SREBP cleavage-activating protein (SCAP) transcripts from SRD-5 cells revealed the presence of a mutation in one SCAP allele that results in substitution of a conserved Leu by Phe at amino acid 315 within the sterol-sensing domain. Sterols fail to inhibit the packaging of SREBP/SCAP(L315F) complexes into budding vesicles . Sterols also fail to induce binding of SCAP(L315F) to insig-1 or insig-2, two proteins that function in the sterol-mediated retention of SREBP/SCAP complexes in the endoplasmic reticulum. Similar findings were observed for SCAP(D443N) and SCAP(Y298C), both of which cause a sterol-resistant phenotype. Thus, three different point mutations, each within the sterol-sensing domain of SCAP, prevent sterol-induced binding of SCAP to insig proteins and abolish feedback regulation of SREBP processing by sterols. IS - 26 JF - Proceedings of the National Academy of Sciences of the United States of America EP - 16677 TI - Three mutations in sterol-sensing domain of {SCAP} block interaction with {I}nsig and render {SREBP} cleavage insensitive to sterols VL - 99 SP - 16672 KW - insig KW - mutation KW - scap KW - sensing KW - srebp KW - sterol AU - Yabe, Daisuke AU - Xia, Zong-Ping AU - Adams, Christopher AU - Rawson, Robert PY - 2002/12/24/ UR - http://dx.doi.org/10.1073/pnas.262669399 ER -