title: Stabilized phosphatidylinositol-5-phosphate analogues as ligands for the nuclear protein ING2: chemistry, biology, and molecular modeling.
abstract: The interaction of PtdIns(5)P with the tumor suppressor protein ING2 has been implicated in the regulation of chromatin modification. To enhance the stability of PtdIns(5)P for studies of the biological role in vivo, two phosphatase-resistant moieties were used to replace the labile 5-phosphate. The total asymmetric synthesis of the 5-methylenephosphonate (MP) and 5-phosphothionate (PT) analogues of PtdIns(5)P is described herein, and the resulting metabolically stabilized lipid analogues were evaluated in three ways. First, liposomes containing either the dioleoyl MP or PT analogues bound to recombinant ING2 similar to liposomes containing dipalmitoyl PtdIns(5)P, indicating that the replacement of the hydrolyzable 5-phosphate group does not compromise the binding. Second, the dioleoyl MP and PT PtdIns(5)P analogues were equivalent to dipalmitoyl PtdIns(5)P in augmenting cell death induced by a DNA double-strand break in HT1080 cells. Finally, molecular modeling and docking of the MP or PT analogues to the C-terminus PtdInsP-binding region of ING2 (consisting of a PHD finger and a polybasic region) revealed a number of complementary surface and electrostatic contacts between the lipids and ING2.
authors.affiliation: Department of Medicinal Chemistry, The University of Utah, 419 Wakara Way, Salt Lake City, UT 84108-1257, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Honglu
authors.initials: H
authors.lastname: Zhang
authors.forename: Foteini
authors.initials: F
authors.lastname: Davrazou
authors.forename: Tatiana G
authors.initials: TG
authors.lastname: Kutateladze
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Shi
authors.forename: Or
authors.initials: O
authors.lastname: Gozani
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Prestwich
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008081:Liposomes; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018129:Phosphatidylinositol Phosphates / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D025521:Tumor Suppressor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018398:Homeodomain Proteins; C444654:ING2 protein, human; D008024:Ligands; D008081:Liposomes; D018129:Phosphatidylinositol Phosphates; D018160:Receptors, Cytoplasmic and Nuclear; D025521:Tumor Suppressor Proteins; C113567:phosphatidylinositol 5-phosphate