PH-PLCδ1 [the PH domain (pleckstrin homology domain) of PLCδ1 (phospholipase C-δ1)] is among the best-characterized phosphoinositide-binding domains. PH-PLCδ1 binds with high specificity to the headgroup of PtdIns(4,5)P2, but little is known about its interfacial properties. In the present study, we show that PH-PLCδ1 is also membrane-active and can insert significantly into PtdIns(4,5)P2-containing monolayers at physiological (bilayer-equivalent) surface pressures. However, this membrane activity appears to involve interactions distinct from those that target PH-PLCδ1 to the PtdIns(4,5)P2 headgroup. Whereas the majority of PtdIns(4,5)P2-bound PH-PLCδ1 can be displaced by adding excess of soluble headgroup [Ins(1,4,5)P3], membrane activity of PH-PLCδ1 cannot. PH-PLCδ1 differs from other phosphoinositide-binding domains in that its membrane insertion does not require that the phosphoinositide-binding site be occupied. Significant monolayer insertion remains when the phosphoinositide-binding site is mutated, and PH-PLCδ1 can insert into monolayers that contain no PtdIns(4,5)P2 at all. Our results suggest a model in which reversible membrane binding of PH-PLCδ1, mediated by PtdIns(4,5)P2 or other acidic phospholipids, occurs without membrane insertion. Accumulation of the PH domain at the membrane surface enhances the efficiency of insertion, but does not significantly affect its extent, whereas the presence of phosphatidylethanolamine and cholesterol in the lipid mixture promotes the extent of insertion. This is the first report of membrane activity in an isolated PH domain and has implications for understanding the membrane targeting by this common type of domain.
Skip Nav Destination
Article navigation
July 2005
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkEditorial Board
Research Article|
July 05 2005
Membrane activity of the phospholipase C-δ1 pleckstrin homology (PH) domain
Frits M. Flesch;
Frits M. Flesch
*Department of Molecular Cell Biology, Faculty of Biology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
Search for other works by this author on:
Jong W. Yu;
Jong W. Yu
†Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, U.S.A.
Search for other works by this author on:
Mark A. Lemmon;
Mark A. Lemmon
1
†Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, U.S.A.
1To whom correspondence should be addressed (email mlemmon@mail.med.upenn.edu or K.N.J.Burger@bio.uu.nl).
Search for other works by this author on:
Koert N. J. Burger
Koert N. J. Burger
1
*Department of Molecular Cell Biology, Faculty of Biology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
‡Department Biochemistry of Membranes, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
1To whom correspondence should be addressed (email mlemmon@mail.med.upenn.edu or K.N.J.Burger@bio.uu.nl).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
October 12 2004
Revision Received:
March 03 2005
Accepted:
March 08 2005
Accepted Manuscript online:
March 08 2005
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London
2005
Biochem J (2005) 389 (2): 435–441.
Article history
Received:
October 12 2004
Revision Received:
March 03 2005
Accepted:
March 08 2005
Accepted Manuscript online:
March 08 2005
Citation
Frits M. Flesch, Jong W. Yu, Mark A. Lemmon, Koert N. J. Burger; Membrane activity of the phospholipase C-δ1 pleckstrin homology (PH) domain. Biochem J 15 July 2005; 389 (2): 435–441. doi: https://doi.org/10.1042/BJ20041721
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.