Reference : Phosphatidylinositol 3,4,5-trisphosphate modulation in Ship2-deficient mouse embryonic f...
Scientific journals : Article
Life sciences : Biochemistry, biophysics & molecular biology Life sciences : Genetics & genetic processes
http://hdl.handle.net/2268/32200
Phosphatidylinositol 3,4,5-trisphosphate modulation in Ship2-deficient mouse embryonic fibroblasts
English
Blero, D.[Université Libre de Bruxelles - ULB > Interdisciplinary Research Institute > > >]
Zhang, J.[Université Libre de Bruxelles - ULB > Interdisciplinary Research Institute (IRIBHM) > > >]
Pesesse, X.[Université Libre de Bruxelles - ULB > Interdisciplinary Research Institute (IRIBHM) > > >]
Payrastre, B.[INSERM U563 > , Departement d’Oncogenese et Signalization dans les Cellules Hematopoietiques, Hoˆ pital Purpan, Toulouse Cedex, France > > >]
Dumont, J. E.[Université Libre de Bruxelles - ULB > Interdisciplinary Research Institute (IRIBHM) > > >]
Schurmans, Stéphane[Université Libre de Bruxelles - ULB > Institut de Recherche Interdisciplinaire en Biologie Humaine et Moleculaire > > >]
Erneux, C.[Université Libre de Bruxelles - ULB > Interdisciplinary Research Institute (IRIBHM) > > >]
[en] SHIP2, the ubiquitous SH2 domain containing inositol 5-phosphatase, includes a series of protein interacting domains and has the ability to dephosphorylate phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] in vitro. The present study, which was undertaken to evaluate the impact of SHIP2 on PtdIns(3,4,5)P3 levels, was performed in a mouse embryonic fibroblast (MEF) model using SHIP2 deficient (– ⁄ –) MEF cells derived from knockout mice. PtdIns(3,4,5)P3 was upregulated in serum stimulated – ⁄ – MEF cells as compared to +⁄+ MEF cells. Although the absence of SHIP2 had no effect on basal PtdIns(3,4,5)P3 levels, we show here that this lipid was significantly upregulated in SHIP2 – ⁄ – cells but only after short-term (i.e. 5–10 min) incubation with serum. The difference in PtdIns(3,4,5)P3 levels in heterozygous fibroblast cells was intermediate between the +⁄+ and the – ⁄ – cells. In our model, insulin-like growth factor-1 stimulation did not show this upregulation. Serum stimulated phosphoinositide 3-kinase (PI 3-kinase) activity appeared to be comparable between +⁄+ and – ⁄ – cells. Moreover, protein kinase B, but not mitogen activated protein kinase activity, was also potentiated in SHIP2 deficient cells stimulated by serum. The upregulation of protein kinase B activity in serum stimulated cells was totally reversed in the presence of the PI 3-kinase inhibitor LY-294002, in both +⁄+ and – ⁄ – cells. Altogether, these data establish a link between SHIP2 and the acute control of PtdIns(3,4,5)P3 levels in intact cells