The PX domain: a new phosphoinositide-binding module.
The PX domain, which until recently was an orphan domain, has emerged as the latest member of the phosphoinositide-binding module superfamily. Structural studies have revealed that it has a novel fold and identified key residues that interact with the bound phosphoinositide, enabling some prediction of phosphoinositide-binding specificity. Specificity for PtdIns(3)P appears to be the most common, and several proteins containing PX domains localise to PtdIns(3)P-rich endosomal and vacuolar structures through their PX domains: these include the yeast t-SNARE Vam7p, mammalian sorting nexins (involved in membrane trafficking events) and the Ser/Thr kinase CISK, which is implicated in cell survival. Additionally, phosphoinositide binding to the PX domains of p40(phox) and p47(phox) appears to play a critical role in the active assembly of the neutrophil oxidase complex.
Ellson
Chris D
CD
The Inositide Laboratory, The Babraham Institute, Babraham, Cambridge, CB2 4AT, UK. chris.ellson@bbsrc.ac.uk
Andrews
Simon
S
Stephens
Len R
LR
Hawkins
Phill T
PT
D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins; D008958:Models, Molecular; D010588:Phagosomes / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D014617:Vacuoles / Q000378:metabolism; D018909:src Homology Domains
D002352:Carrier Proteins; D005136:Eye Proteins; D050556:Fatty Acid-Binding Proteins; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C055525:phosphatidylinositol 3-phosphate