Biophysical studies of membrane proteins/peptides. Interaction with ...

CLUSTERING OF PI(4,5)P 2 IN FLUID PC BILAYERS
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CLUSTERING OF PI(4,5)P2 IN
FLUID PC BILAYERS
1. Introduction
Phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P ) (Figure VI-1) is the most
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abundant polyphosphatidylinositide in mammalian cells. It is however only a minor
component of the plasma membrane. In human erythrocytes PI(4,5)P comprises about
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1% of the total lipid content of the plasma membrane (McLaughlin et al., 2002),
nevertheless it is responsible for the regulation of many essential cellular functions. Its
role as a precursor of two second messengers, diacylglycerol and inositol 1,4,5-
trisphosphate is well established (van Rheenen et al., 2005), and it is now recognized to
act as signal for channel gating and for establishing sites for vesicular trafficking,
membrane remodelling and movement, and actin cytoskeletal assembly (Martin, 2001).
PI(4,5)P is also expected to act merely as a protein anchor to the plasma membrane in
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some cases (McLaughlin, 2002).
Figure VI-1: Structure of 1,2-dioleoyl-sn-glycero-3-phosphatidylinositol-(4,5)-bisphosphate.
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