To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Optical manipulation reve… - University of Gothenburg, Sweden Till startsida
Sitemap
To content Read more about how we use cookies on gu.se

Optical manipulation reveals strong attracting forces at membrane contact sites between endoplasmic reticulum and chloroplasts

Journal article
Authors Mats X. Andersson
Mattias Goksör
Anna Stina Sandelius
Published in Journal of Biological Chemistry
Volume 282
Issue 2
Pages 1170-1174
ISSN 0021-9258
Publication year 2007
Published at Department of Plant and Environmental Sciences
Department of Physics (GU)
Pages 1170-1174
Language en
Links http//dx.doi.org/10.1074/jbc.M60812...
Subject categories Biological Sciences, Biophysics, Botany

Abstract

Eukaryote cells depend on membrane lipid trafficking from biogenic membranes, like the endoplasmic reticulum (ER), to other membranes in the cell. Two major routes for membrane lipid transport are recognized: vesicular trafficking and lipid transfer at zones of close contact between membranes. Specific ER regions involved in such membrane contact sites (MCSs) have been isolated, and lipid transfer at MCSs as well as protein-protein interactions between the partaking membranes have been demonstrated (reviewed by Holthuis, J. C. M., and Levine, T. P. (2005) Nat. Rev. 6, 209–220). Here we present the first demonstration of the physical association between membranes involved in MCSs: by using optical imaging and manipulation, strong attracting forces between ER and chloroplasts are revealed. We used Arabidopsis thaliana expressing green fluorescent protein in the ER lumen and observed leaf protoplasts by confocal microscopy. The ER network was evident, with ER branch end points apparently localized at chloroplast surfaces. After rupture of a protoplast using a laser scalpel, the cell content was released. ER fragments remained attached to the released chloroplasts and could be stretched out by optical tweezers. The applied force, 400 pN, could not drag a chloroplast free from its attached ER, which could reflect protein-protein interactions at the ER-chloroplast MCSs. As chloroplasts rely on import of ER-synthesized lipids, we propose that lipid transfer occurs at these MCSs. We suggest that lipid transfer at the MCSs also occurs in the opposite direction, for example to channel plastid-synthesized acyl groups to supply substrates for ER-localized synthesis of membrane and storage lipids.

Page Manager: Webmaster|Last update: 9/11/2012
Share:

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?