Document Detail


Decrease in membrane phospholipid unsaturation induces unfolded protein response.
MedLine Citation:
PMID:  20489212     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Various kinds of fatty acids are distributed in membrane phospholipids in mammalian cells and tissues. The degree of fatty acid unsaturation in membrane phospholipids affects many membrane-associated functions and can be influenced by diet and by altered activities of lipid-metabolizing enzymes such as fatty acid desaturases. However, little is known about how mammalian cells respond to changes in phospholipid fatty acid composition. In this study we showed that stearoyl-CoA desaturase 1 (SCD1) knockdown increased the amount of saturated fatty acids and decreased that of monounsaturated fatty acids in phospholipids without affecting the amount or the composition of free fatty acid and induced unfolded protein response (UPR), evidenced by increased expression of C/EBP homologous protein (CHOP) and glucose-regulated protein 78 (GRP78) mRNAs and splicing of Xbox-binding protein 1 (XBP1) mRNA. SCD1 knockdown-induced UPR was rescued by various unsaturated fatty acids and was enhanced by saturated fatty acid. Lysophosphatidylcholine acyltransferase 3 (LPCAT3), which incorporates preferentially polyunsaturated fatty acids into phosphatidylcholine, was up-regulated in SCD1 knockdown cells. Knockdown of LPCAT3 synergistically enhanced UPR with SCD1 knockdown. Finally we showed that palmitic acid-induced UPR was significantly enhanced by LPCAT3 knockdown as well as SCD1 knockdown. These results suggest that a decrease in membrane phospholipid unsaturation induces UPR.
Authors:
Hiroyuki Ariyama; Nozomu Kono; Shinji Matsuda; Takao Inoue; Hiroyuki Arai
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-05-20
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  285     ISSN:  1083-351X     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-07-12     Completed Date:  2010-08-06     Revised Date:  2010-10-07    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  22027-35     Citation Subset:  IM    
Affiliation:
Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
1-Acylglycerophosphocholine O-Acyltransferase / deficiency,  metabolism
Cell Death / drug effects
Cell Membrane / drug effects,  metabolism*
Fatty Acids, Unsaturated / metabolism*
Gene Knockdown Techniques
Hela Cells
Humans
Palmitic Acid / pharmacology,  toxicity
Phospholipids / chemistry*
Stearoyl-CoA Desaturase / deficiency,  metabolism
Unfolded Protein Response* / drug effects
Up-Regulation / drug effects
eIF-2 Kinase / metabolism
Chemical
Reg. No./Substance:
0/Fatty Acids, Unsaturated; 0/Phospholipids; 57-10-3/Palmitic Acid; EC 1.14.19.1/Stearoyl-CoA Desaturase; EC 2.3.1.23/1-Acylglycerophosphocholine O-Acyltransferase; EC 2.3.1.23/LPCAT3 protein, human; EC 2.7.10.-/PERK kinase; EC 2.7.11.1/eIF-2 Kinase
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Crystal structure of the entire ectodomain of gp130: insights into the molecular assembly of the tal...
Next Document:  Efficacy of surgery for femoroacetabular impingement: a systematic review.