Article
- The EMBO Journal (2004) 23, 3918 - 3928
- doi:10.1038/sj.emboj.7600379
Published online: 30 September 2004
Subject Categories:
Structural insights into the regulation of PDK1 by phosphoinositides and inositol phosphates
David Komander1,3, Alison Fairservice2, Maria Deak3, Gursant S Kular3, Alan R Prescott4, C Peter Downes2, Stephen T Safrany2, Dario R Alessi3 and Daan MF van Aalten1
- Division of Biological Chemistry & Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
- Division of Cell Signalling, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
- MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
- Division of Cell Biology and Immunology, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
Correspondence to:
Daan MF van Aalten, Wellcome Trust Biocentre, School of Life Sciences, University of Dundee, MSI/WTB Complex, Dundee DD1 5EH, UK. Tel.: +44 1382 344 979; Fax: +44 1382 345 764; E-mail: dava@davapc1.bioch.dundee.ac.uk
Received 2 June 2004; Accepted 29 July 2004
Abstract
3-phosphoinositide-dependent protein kinase-1 (PDK1) phosphorylates and activates many kinases belonging to the AGC subfamily. PDK1 possesses a C-terminal pleckstrin homology (PH) domain that interacts with PtdIns(3,4,5)P3/PtdIns(3,4)P2 and with lower affinity to PtdIns(4,5)P2. We describe the crystal structure of the PDK1 PH domain, in the absence and presence of PtdIns(3,4,5)P3 and Ins(1,3,4,5)P4. The structures reveal a 'budded' PH domain fold, possessing an N-terminal extension forming an integral part of the overall fold, and display an unusually spacious ligand-binding site. Mutagenesis and lipid-binding studies were used to define the contribution of residues involved in phosphoinositide binding. Using a novel quantitative binding assay, we found that Ins(1,3,4,5,6)P5 and InsP6, which are present at micromolar levels in the cytosol, interact with full-length PDK1 with nanomolar affinities. Utilising the isolated PDK1 PH domain, which has reduced affinity for Ins(1,3,4,5,6)P5/InsP6, we perform localisation studies that suggest that these inositol phosphates serve to anchor a portion of cellular PDK1 in the cytosol, where it could activate its substrates such as p70 S6-kinase and p90 ribosomal S6 kinase that do not interact with phosphoinositides.
Keywords:
- inositol phosphates,
- phosphoinositides,
- PI-3 kinase pathway,
- protein crystallography,
- protein structure
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated
REVIEWS
Membrane recognition by phospholipid-binding domains
Nature Reviews Molecular Cell Biology Review (01 Feb 2008)
Nature Reviews Molecular Cell Biology Review (01 Feb 2008)
Analyzing phosphoinositides and their interacting proteins
Nature Methods Review (01 Apr 2006)
NEWS AND VIEWS
Calcium?myristoyl switches turn on new lights
Nature Cell Biology News and Views (01 Aug 1999)
RESEARCH
Possible involvement of terminal complement complex in active Heymann nephritis
Kidney International Original Article
