PI3K regulates pleckstrin-2 in T-cell cytoskeletal reorganization
Open Access
- 28 September 2006
- journal article
- Published by American Society of Hematology in Blood
- Vol. 109 (3) , 1147-1155
Abstract
Pleckstrin-2 is composed of 2 pleckstrin homology (PH) domains and a disheveled–Egl-10–pleckstrin (DEP) domain. A lipid-binding assay revealed that pleckstrin-2 binds with greatest affinity to D3 and D5 phosphoinositides. Pleckstrin-2 expressed in Jurkat T cells bound to the cellular membrane and enhanced actin-dependent spreading only after stimulation of the T-cell antigen receptor or the integrin α4β1. A pleckstrin-2 variant containing point mutations in both PH domains failed to associate with the Jurkat membrane and had no effect on spreading under the same conditions. Although still membrane bound, a pleckstrin-2 variant containing point mutations in the DEP domain demonstrated a decreased ability to induce membrane ruffles and spread. Pleckstrin-2 also colocalized with actin at the immune synapse and integrin clusters via its PH domains. Although pleckstrin-2 can bind to purified D3 and D5 phosphoinositides, the intracellular membrane association of pleckstrin-2 and cell spreading are dependent on D3 phosphoinositides, because these effects were disrupted by pharmacologic inhibition of phosphatidylinositol 3-kinase (PI3K). Our results indicate that pleckstrin-2 uses its modular domains to bind to membrane-associated phosphatidylinositols generated by PI3K, whereby it coordinates with the actin cytoskeleton in lymphocyte spreading and immune synapse formation.Keywords
This publication has 53 references indexed in Scilit:
- Structure and dynamics of the human pleckstrin DEP domain: Distinct molecular features of a novel DEP domain subfamilyProteins: Structure, Function, and Bioinformatics, 2004
- T Cell Receptor Engagement Leads to the Recruitment of IBP, a Novel Guanine Nucleotide Exchange Factor, to the Immunological SynapseJournal of Biological Chemistry, 2003
- Specific Binding of RGS9-Gβ5L to Protein Anchor in Photoreceptor Membranes Greatly Enhances Its Catalytic ActivityJournal of Biological Chemistry, 2002
- WASP Recruitment to the T Cell:APC Contact Site Occurs Independently of Cdc42 ActivationImmunity, 2001
- Endoproteolytic Processing of Sst2, a Multidomain Regulator of G Protein Signaling in YeastJournal of Biological Chemistry, 2000
- Regulators of G Protein SignalingJournal of Neurochemistry, 2000
- Functional Association between SLAP-130 and SLP-76 in Jurkat T CellsJournal of Biological Chemistry, 2000
- Pleckstrin Associates with Plasma Membranes and Induces the Formation of Membrane Projections: Requirements for Phosphorylation and the NH2-terminal PH DomainJournal of Cell Biology, 1997
- Pleckstrin's repeat performance: a novel domain in G-protein signaling?Trends in Biochemical Sciences, 1996
- Site-directed mutagenesis by overlap extension using the polymerase chain reactionGene, 1989