title: SHIP2 signalling at the plasma membrane, in the nucleus and at focal contacts.
abstract: Phosphoinositide 5-phosphatases are critical enzymes in modulating the concentrations of PI(3,4,5)P(3), PI(4,5)P(2) and PI(3,5)P(2). The SH2 domain containing inositol 5-phosphatases SHIP1 and SHIP2 belong to this family of enzymes very much involved in physiopathology and development. Therefore activity and localization of the enzymes are particularly important taking into account both catalytic and non-catalytic mechanisms of the SHIP phosphatases. Several different mechanisms have been reported for SHIP2 targeting that often result from specific protein:protein interactions. In unstimulated astrocytoma cells, SHIP2 has a perinuclear and cytoplasmic localization. In serum-stimulated cells, SHIP2 can be localized at the plasma membrane and at focal contacts in polarized cells. A phosphorylated form of SHIP2 on S132 can be found in the nucleus and nuclear speckles. When present at the plasma membrane, SHIP2 may control the intracellular level of PI(3,4,5)P(3) thereby producing PI(3,4)P(2). When present in the nucleus, SHIP2 probably associates to other nuclear proteins such as lamin A/C and could potentially control nuclear PI(4,5)P(2). Finally, its presence at focal adhesions and lamellipodia could suggest a role in cell adhesion and migration. It is proposed that the complex phenotype observed in SHIP2 mutant mice in tissue development and growth could result from the addition of plasma membrane and nuclear effects consecutive to SHIP2 alteration.
authors.affiliation: Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Campus Erasme, Bldg. C, 808 Route de Lennik, 1070 Brussels, Belgium.
authors.forename: William's
authors.initials: W
authors.lastname: Elong Edimo
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Vanderwinden
authors.forename: Christophe
authors.initials: C
authors.lastname: Erneux
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D022001:Focal Adhesions / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D000072181:Inositol Polyphosphate 5-Phosphatases; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010716:Phosphatidylinositols / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015398:Signal Transduction
chemical_list: D007527:Isoenzymes; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C106336:phosphatidylinositol 3,5-diphosphate; C118303:phosphoinositide-3,4,5-triphosphate; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases; C000606430:INPP5D protein, human; C000606433:Inpp5d protein, mouse; C000606435:Inppl1 protein, mouse; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases