JCB logo
Avanti Polar Lipids, Inc.
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 457K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ma, A. D.
Right arrow Articles by Abrams, C. S.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Ma, A. D.
Right arrow Articles by Abrams, C. S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/1997//1071 $5.00
The Journal of Cell Biology, Volume 136, Number 5, , 1997 1071-1079

Article

Pleckstrin Associates with Plasma Membranes and Induces the Formation of Membrane Projections: Requirements for Phosphorylation and the NH2-terminal PH Domain



Alice D. Ma*, Lawrence F. Brass*,{ddagger}, and Charles S. Abrams*

* Department of Medicine, {ddagger} Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104

Pleckstrin homology (PH) domains are sequences of ~100 amino acids that form "modules" that have been proposed to facilitate protein/protein or protein/lipid interactions. Pleckstrin, first described as a substrate for protein kinase C in platelets and leukocytes, is composed of two PH domains, one at each end of the molecule, flanking an intervening sequence of 147 residues. Evidence is accumulating to support the hypothesis that PH domains are structural motifs that target molecules to membranes, perhaps through interactions with Gβ{gamma} or phosphatidylinositol 4,5-bisphosphate (PIP2), two putative PH domain ligands. In the present studies, we show that pleckstrin associates with membranes in human platelets. We further demonstrate that, in transfected Cos-1 cells, pleckstrin associates with peripheral membrane ruffles and dorsal membrane projections. This association depends on phosphorylation of pleckstrin and requires the presence of its NH2-terminal, but not its COOH-terminal, PH domain. Moreover, PH domains from other molecules cannot effectively substitute for pleckstrin's NH2terminal PH domain in directing membrane localization. Lastly, we show that wild-type pleckstrin actually promotes the formation of membrane projections from the dorsal surface of transfected cells, and that this morphologic change is similarly PH domain dependent. Since we have shown previously that pleckstrin-mediated inhibition of PIP2 metabolism by phospholipase C or phosphatidylinositol 3-kinase also requires pleckstrin phosphorylation and an intact NH2-terminal PH domain, these results suggest that: (a) pleckstrin's NH2terminal PH domain may regulate pleckstrin's activity by targeting it to specific areas within the cell membrane; and (b) pleckstrin may affect membrane structure, perhaps via interactions with PIP2 and/or other membrane-bound ligands.

Abbreviations used in this paper: βARK, β–adrenergic receptor kinase; Gβ{gamma}, β{gamma}; subunit of heterotrimeric GTP-binding proteins; HA, hemagglutinin; PH, pleckstrin homology; PI3-K, phosphatidylinositol 3-kinase; PIP2, phosphatidylinositol 4,5-bisphosphate; PLC, phospholipase C.

Address all correspondence to Dr. Charles S. Abrams, Hematology- Oncology Division, University of Pennsylvania School of Medicine, 422 Curie Blvd., Stellar-Chance Labs #1005, Philadelphia, PA 19104. Tel.: (215) 898-1058. Fax: (215) 662-7617. e-mail: abramsc{at}mail.med.upenn.edu


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents