UNIGE document Scientific Article
previous document  unige:81646  next document
add to browser collection

Specific release of membrane-bound annexin II and cortical cytoskeletal elements by sequestration of membrane cholesterol

Kellner, Roland
Parton, Robert G.
Published in Molecular Biology of the Cell. 1997, vol. 8, no. 3, p. 533-545
Abstract Annexin II is an abundant protein which is present in the cytosol and on the cytoplasmic face of plasma membrane and early endosomes. It is generally believed that this association occurs via Ca2+-dependent binding to lipids, a mechanism typical for the annexin protein family. Although previous studies have shown that annexin II is involved in early endosome dynamics and organization, the precise biological role of the protein is unknown. In this study, we found that approximately 50% of the total cellular annexin was associated with membranes in a Ca2+-independent manner. This binding was extremely tight, since it resisted high salt and, to some extent, high pH treatments. We found, however, that membrane-associated annexin II could be quantitatively released by low concentrations of the cholesterol-sequestering agents filipin and digitonin. Both treatments released an identical and limited set of proteins but had no effects on other membrane-associated proteins. Among the released proteins, we identified, in addition to annexin II itself, the cortical cytoskeletal proteins a-actinin, ezrin and moesin, and membrane-associated actin. Our biochemical and immunological observations indicate that these proteins are part of a complex containing annexin II and that stability of the complex is sensitive to cholesterol sequestering agents. Since annexin II is tightly membrane-associated in a cholesterol-dependent manner, and since it seems to interact physically with elements of the cortical actin cytoskeleton, we propose that the protein serves as interface between membranes containing high amounts of cholesterol and the actin cytoskeleton.
Full text
(ISO format)
HARDER, Thomas et al. Specific release of membrane-bound annexin II and cortical cytoskeletal elements by sequestration of membrane cholesterol. In: Molecular Biology of the Cell, 1997, vol. 8, n° 3, p. 533-545. https://archive-ouverte.unige.ch/unige:81646

129 hits

0 download


Deposited on : 2016-03-08

Export document
Format :
Citation style :