Journal
JOURNAL OF BIOCHEMISTRY
Volume 163, Issue 4, Pages 313-319Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jb/mvx083
Keywords
cholesterol; diacylglycerol; liposomes; membrane protein insertion; phosphatidylcholine
Categories
Funding
- JSPS KAKENHI [25291009, 26102703, 26119701, 15KT0073, 16H01374, 16K15083, 17H02209, 26102722, 16K05648]
- Grants-in-Aid for Scientific Research [17H02209, 16H01374] Funding Source: KAKEN
Ask authors/readers for more resources
Spontaneous insertion of membrane proteins into liposomes formed from Escherichia coli polar phospholipids is blocked by diacylglycerol (DAG) at a physiological level. We found that cholesterol also blocks this spontaneous insertion, although a much larger amount is necessary for sufficient blockage. Reversely, sphingomyelin enhanced the spontaneous insertion. DAG at a physiological level was found not to block spontaneous insertion into liposomes formed from phosphatidylcholine (PC), while non-physiologically high concentrations of DAG reduced it. On the other hand, cholesterol blocked the spontaneous insertion into PC liposomes at a physiological level, explaining that both PC and cholesterol are absent in E. coli. While sphingomyelin did not enhance spontaneous insertion into PC liposomes, the effect of cholesterol on blockage of spontaneous insertion was dominant over that of sphingomyelin, suggesting that cholesterol functions as a blocker of disordered spontaneous insertion in eukaryotic cells. Lower amount of cholesterol was necessary to block spontaneous insertion into ER-mimic liposomes, explaining that ER membranes contain less amount of cholesterol. These results also explain that cholesterol, but not DAG, is involved in blockage of spontaneous insertion in eukaryotic cells, since DAG plays an important role as a second messenger in signal transduction.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available