Molecular Biology of the Cell Call for Nominations: MBC Editor-in-Chief

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

MBC in Press, published online ahead of print May 2, 2007
Mol. Biol. Cell 10.1091/mbc.E06-10-0924

A more recent version of this article appeared on July 1, 2007
This Article
Right arrow Full Text (PDF)
Right arrow Supplemental Material
Right arrow All Versions of this Article:
E06-10-0924v1
18/7/2667    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Takahashi, M.
Right arrow Articles by Kobayashi, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Takahashi, M.
Right arrow Articles by Kobayashi, T.

Submitted on October 17, 2006
Revised on April 20, 2007
Accepted on April 24, 2007

Cholesterol Controls Lipid Endocytosis through Rab11

Miwa Takahashi,*{dagger} Motohide Murate,* Mitsunori Fukuda,{ddagger}{sect} Satoshi B. Sato,*|| Akinori Ohta,{dagger} and Toshihide Kobayashi*¶#

*RIKEN Frontier Research System, Wako, Saitama 351-0198, Japan; {dagger}Department of Biotechnology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan; {ddagger}Fukuda Initiative Research Unit and Lipid Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; {sect}Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan; ||Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan; #INSERM U870, INRA U1235, INSA-Lyon, University Lyon 1 and Hospices Civils de Lyon, 69621 Villeurbanne, France

Monitoring Editor: Robert Parton

Cellular cholesterol increases when cells reach confluency in Chinese hamster ovary (CHO) cells. We examined the endocytosis of several lipid probes in subconfluent and confluent CHO cells. In subconfluent cells, fluorescent lipid probes including poly(ethylene glycol)derivatized cholesterol, 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3{beta}-ol and fluorescent sphingomyelin analogs were internalized to pericentriolar recycling endosomes. This accumulation was not observed in confluent cells. Internalization of fluorescent lactosylceramide was not affected by cell confluency, suggesting that the endocytosis of specific membrane components is affected by cell confluency. The crucial role of cellular cholesterol in cell-confluency dependent endocytosis was suggested by the observation that the fluorescent sphingomyelin was transported to recycling endosomes when cellular cholesterol was depleted in confluent cells. To understand the molecular mechanism(s) of cell confluency- and cholesterol-dependent endocytosis, we examined intracellular distribution of rab small GTPases. Our results indicate that rab11 but not rab4, altered intracellular localization in a cell confluency-associated manner and this alteration was dependent on cell cholesterol. In addition, the expression of a constitutive active mutant of rab11 changed the endocytic route of lipid probes from early to recycling endosomes. These results thus suggest that cholesterol controls endocytic routes of a subset of membrane lipids through rab11.

Address correspondence to: Toshihide Kobayashi (kobayasi{at}riken.jp)






Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Copyright © 2007 by The American Society for Cell Biology. Terms of copyright protection, warranties, and disclaimers.