title: Phospholipid-binding sites of phosphatase and tensin homolog (PTEN): exploring the mechanism of phosphatidylinositol 4,5-bisphosphate activation.
abstract: The lipid phosphatase activity of the tumor suppressor phosphatase and tensin homolog (PTEN) is enhanced by the presence of its biological product, phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This enhancement is suggested to occur via the product binding to the N-terminal region of the protein. PTEN effects on short-chain phosphoinositide (31)P linewidths and on the full field dependence of the spin-lattice relaxation rate (measured by high resolution field cycling (31)P NMR using spin-labeled protein) are combined with enzyme kinetics with the same short-chain phospholipids to characterize where PI(4,5)P2 binds on the protein. The results are used to model a discrete site for a PI(4,5)P2 molecule close to, but distinct from, the active site of PTEN. This PI(4,5)P2 site uses Arg-47 and Lys-13 as phosphate ligands, explaining why PTEN R47G and K13E can no longer be activated by that phosphoinositide. Placing a PI(4,5)P2 near the substrate site allows for proper orientation of the enzyme on interfaces and should facilitate processive catalysis.
authors.affiliation: From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wei
authors.affiliation: From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and.
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Stec
authors.affiliation: the Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02454.
authors.forename: Alfred G
authors.initials: AG
authors.lastname: Redfield
authors.affiliation: From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and.
authors.forename: Eranthie
authors.initials: E
authors.lastname: Weerapana
authors.affiliation: From the Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467 and mary.roberts@bc.edu.
authors.forename: Mary F
authors.initials: MF
authors.lastname: Roberts
mesh_terms: D000495:Allosteric Site; D020134:Catalytic Domain; D006801:Humans; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008823:Micelles; D009154:Mutation; D051059:PTEN Phosphohydrolase / Q000737:chemistry*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000737:chemistry*; D010716:Phosphatidylinositols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D008823:Micelles; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D010743:Phospholipids; D011994:Recombinant Proteins; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: 31P Field Cycling; Enzyme Kinetics; Micelles; Nuclear Magnetic Resonance (NMR); Phosphatase and Tensin Homolog (PTEN); Phosphatidylinositol Phosphatase; Phosphoinositide; Phospholipid-binding Site; Spin-labeled Protein