Cookies

We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.


Durham Research Online
You are in:

Phosphatidylserine exposure in B lymphocytes : a role for lipid packing.

Elliott, J. I. and Sardini, A. and Cooper, J. C. and Alexander, D. R. and Davanture, S. and Chimini, G. and Higgins, C. F. (2006) 'Phosphatidylserine exposure in B lymphocytes : a role for lipid packing.', Blood., 108 (5). pp. 1611-1617.

Abstract

Plasma membrane lipids are usually distributed asymmetrically, with phosphatidylserine (PS) confined to the inner leaflet. PS exposure at the outer leaflet occurs early in apoptosis, but it is also constitutive on some nonapoptotic cell populations where it plays a role in cell signaling. How PS is transported ("flopped") to the cell surface is unknown. Contrary to previous reports that normal murine B lymphocytes lack lipid asymmetry, we show that PS is normally restricted to the inner leaflet of these cells. PS exposure on normal B cells did, however, occur spontaneously ex vivo. Consistent with the hypothesis that loss of PS asymmetry is regulated by CD45, PS is constitutively exposed on viable, CD45-deficient B cells. We show that calcium-stimulated PS exposure in B cells is strain variable, ABCA1 independent, and both preceded by and dependent on a decrease in lipid packing. This decrease in lipid packing is concomitant with cell shrinkage and consequent membrane distortion, both of which are potently inhibited by blockers of volume-regulatory K+ and Cl- ion channels. Thus, changes in plasma membrane organization precede PS translocation. The data suggest a model in which PS redistribution may occur by a translocase-independent mechanism at energetically favorable sites of membrane perturbation where lipid packing is decreased.

Item Type:Article
Full text:Full text not available from this repository.
Publisher Web site:http://dx.doi.org/10.1182/blood-2005-11-012328
Record Created:15 May 2007
Last Modified:28 Jan 2011 13:04

Social bookmarking: del.icio.usConnoteaBibSonomyCiteULikeFacebookTwitterExport: EndNote, Zotero | BibTex
Usage statisticsLook up in GoogleScholar | Find in a UK Library