title: Stimulation of nuclear polyphosphoinositide synthesis by GTP-gamma-S: a potential regulatory role for nuclear GTP-binding proteins.
abstract: The nonhydrolyzable GTP analogue GTP-gamma-S was capable of stimulating in vitro phosphorylation of polyphosphoinositides in isolated nuclei prepared from mouse erythroleukemia cells. On the contrary, GDP-beta-S was ineffective. The stimulation was not detectable when nuclei were prepared from erythroleukemia cells induced to differentiate by exposure to dimethyl sulfoxide. Both nuclear phosphomonoesterase and phospholipase C activities were not influenced by GTP-gamma-S. Our results point to the likelihood that nuclear phosphoinositide kinases might be regulated by a GTP-binding protein.
authors.affiliation: Dipartimento di Morfologia Umana Normale, Trieste, Italy.
authors.forename: A M
authors.initials: AM
authors.lastname: Martelli
authors.forename: R
authors.initials: R
authors.lastname: Bareggi
authors.forename: L
authors.initials: L
authors.lastname: Cocco
authors.forename: F A
authors.initials: FA
authors.lastname: Manzoli
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006706:Homeostasis; D007700:Kinetics; D004915:Leukemia, Erythroblastic, Acute; D007942:Leukemia, Experimental; D051379:Mice; D018129:Phosphatidylinositol Phosphates / Q000096:biosynthesis*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D018129:Phosphatidylinositol Phosphates; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D010744:Phosphoric Monoester Hydrolases; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D004121:Dimethyl Sulfoxide