title: High-affinity binding of a FYVE domain to phosphatidylinositol 3-phosphate requires intact phospholipid but not FYVE domain oligomerization.
abstract: FYVE domains are small zinc-finger-like domains found in many proteins that are involved in regulating membrane traffic and have been shown to bind specifically to phosphatidylinositol 3-phosphate (PtdIns-3-P). FYVE domains are thought to recruit PtdIns-3-P effectors to endosomal locations in vivo, where these effectors participate in controlling endosomal maturation and vacuolar protein sorting. We have compared the characteristics of PtdIns-3-P binding by the FYVE domain from Hrs-1 (the hepatocyte growth factor-regulated tyrosine kinase substrate) with those of specific phosphoinositide binding by Pleckstrin homology (PH) domains. Like certain PH domains (such as that from phospholipase C-delta(1)), the Hrs-1 FYVE domain specifically recognizes a single phosphoinositide. However, while phosphoinositide binding by highly specific PH domains is driven almost exclusively by interactions with the lipid headgroup, this is not true for the Hrs-1 FYVE domain. The phospholipase C-delta(1) PH domain shows a 10-fold preference for binding isolated headgroup over its preferred lipid (phosphatidylinositol 4,5-bisphosphate) in a membrane, while the Hrs-1 FYVE domain greatly prefers (more than 50-fold) intact lipid in a bilayer over the isolated headgroup (inositol 1,3-bisphosphate). By contrast with reports for certain PH domains, we find that this preference for membrane binding over interaction with soluble lipid headgroups does not require FYVE domain oligomerization.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
authors.forename: V G
authors.initials: VG
authors.lastname: Sankaran
authors.forename: D E
authors.initials: DE
authors.lastname: Klein
authors.forename: M M
authors.initials: MM
authors.lastname: Sachdeva
authors.forename: M A
authors.initials: MA
authors.lastname: Lemmon
mesh_terms: D001667:Binding, Competitive / Q000235:genetics; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins; D005982:Glutathione Transferase / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors; D006367:HeLa Cells; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D009004:Monosaccharide Transport Proteins; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D027981:Symporters; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D001798:Blood Proteins; D002352:Carrier Proteins; D027682:Cation Transport Proteins; C490796:FGD1 protein, human; D020662:Guanine Nucleotide Exchange Factors; D008081:Liposomes; D009004:Monosaccharide Transport Proteins; D018129:Phosphatidylinositol Phosphates; D010743:Phospholipids; D010750:Phosphoproteins; D011506:Proteins; C101014:RSC1A1 protein, human; D011993:Recombinant Fusion Proteins; D027981:Symporters; C055525:phosphatidylinositol 3-phosphate; C039077:platelet protein P47; D005982:Glutathione Transferase