Abstract
Type IB phosphoinositide 3OH-kinase (PI3K) is activated by G-protein betagamma subunits (Gbetagammas). The enzyme is soluble and largely cytosolic in vivo. Its substrate, PtdIns(4,5)P(2), and the Gbetagammas are localized at the plasma membrane. We have addressed the mechanism by which Gbetagammas regulate the PI3K using an in vitro approach. We used sedimentation assays and surface plasmon resonance to determine association of type IB PI3K with lipid monolayers and vesicles of varying compositions, some of which had Gbetagammas incorporated. Association and dissociation rate constants were determined. Our results indicated that in an assay situation in vitro the majority of PI3K will be associated with lipid vesicles, irrespective of the presence or absence of Gbetagammas. In line with this, a constitutively active membrane-targeted PI3K construct could still be activated substantially by Gbetagammas in vitro. We conclude that Gbetagammas activate type IB PI3K by a mechanism other than translocation to the plasma membrane.
Full Text
The Full Text of this article is available as a PDF (228.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Auger K. R., Serunian L. A., Soltoff S. P., Libby P., Cantley L. C. PDGF-dependent tyrosine phosphorylation stimulates production of novel polyphosphoinositides in intact cells. Cell. 1989 Apr 7;57(1):167–175. doi: 10.1016/0092-8674(89)90182-7. [DOI] [PubMed] [Google Scholar]
- Backer J. M., Myers M. G., Jr, Shoelson S. E., Chin D. J., Sun X. J., Miralpeix M., Hu P., Margolis B., Skolnik E. Y., Schlessinger J. Phosphatidylinositol 3'-kinase is activated by association with IRS-1 during insulin stimulation. EMBO J. 1992 Sep;11(9):3469–3479. doi: 10.1002/j.1460-2075.1992.tb05426.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bondeva T., Pirola L., Bulgarelli-Leva G., Rubio I., Wetzker R., Wymann M. P. Bifurcation of lipid and protein kinase signals of PI3Kgamma to the protein kinases PKB and MAPK. Science. 1998 Oct 9;282(5387):293–296. doi: 10.1126/science.282.5387.293. [DOI] [PubMed] [Google Scholar]
- Carpenter C. L., Auger K. R., Chanudhuri M., Yoakim M., Schaffhausen B., Shoelson S., Cantley L. C. Phosphoinositide 3-kinase is activated by phosphopeptides that bind to the SH2 domains of the 85-kDa subunit. J Biol Chem. 1993 May 5;268(13):9478–9483. [PubMed] [Google Scholar]
- Cooper M. A., Try A. C., Carroll J., Ellar D. J., Williams D. H. Surface plasmon resonance analysis at a supported lipid monolayer. Biochim Biophys Acta. 1998 Aug 14;1373(1):101–111. doi: 10.1016/s0005-2736(98)00091-1. [DOI] [PubMed] [Google Scholar]
- Hiles I. D., Otsu M., Volinia S., Fry M. J., Gout I., Dhand R., Panayotou G., Ruiz-Larrea F., Thompson A., Totty N. F. Phosphatidylinositol 3-kinase: structure and expression of the 110 kd catalytic subunit. Cell. 1992 Aug 7;70(3):419–429. doi: 10.1016/0092-8674(92)90166-a. [DOI] [PubMed] [Google Scholar]
- Hu P., Mondino A., Skolnik E. Y., Schlessinger J. Cloning of a novel, ubiquitously expressed human phosphatidylinositol 3-kinase and identification of its binding site on p85. Mol Cell Biol. 1993 Dec;13(12):7677–7688. doi: 10.1128/mcb.13.12.7677. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Inukai K., Anai M., Van Breda E., Hosaka T., Katagiri H., Funaki M., Fukushima Y., Ogihara T., Yazaki Y., Kikuchi A novel 55-kDa regulatory subunit for phosphatidylinositol 3-kinase structurally similar to p55PIK Is generated by alternative splicing of the p85alpha gene. J Biol Chem. 1996 Mar 8;271(10):5317–5320. doi: 10.1074/jbc.271.10.5317. [DOI] [PubMed] [Google Scholar]
- Jenco J. M., Becker K. P., Morris A. J. Membrane-binding properties of phospholipase C-beta1 and phospholipaseC-beta2: role of the C-terminus and effects of polyphosphoinositides, G-proteins and Ca2+. Biochem J. 1997 Oct 15;327(Pt 2):431–437. doi: 10.1042/bj3270431. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klippel A., Escobedo J. A., Fantl W. J., Williams L. T. The C-terminal SH2 domain of p85 accounts for the high affinity and specificity of the binding of phosphatidylinositol 3-kinase to phosphorylated platelet-derived growth factor beta receptor. Mol Cell Biol. 1992 Apr;12(4):1451–1459. doi: 10.1128/mcb.12.4.1451. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Krugmann S., Hawkins P. T., Pryer N., Braselmann S. Characterizing the interactions between the two subunits of the p101/p110gamma phosphoinositide 3-kinase and their role in the activation of this enzyme by G beta gamma subunits. J Biol Chem. 1999 Jun 11;274(24):17152–17158. doi: 10.1074/jbc.274.24.17152. [DOI] [PubMed] [Google Scholar]
- Lopez-Ilasaca M., Crespo P., Pellici P. G., Gutkind J. S., Wetzker R. Linkage of G protein-coupled receptors to the MAPK signaling pathway through PI 3-kinase gamma. Science. 1997 Jan 17;275(5298):394–397. doi: 10.1126/science.275.5298.394. [DOI] [PubMed] [Google Scholar]
- Maier U., Babich A., Macrez N., Leopoldt D., Gierschik P., Illenberger D., Nurnberg B. Gbeta 5gamma 2 is a highly selective activator of phospholipid-dependent enzymes. J Biol Chem. 2000 May 5;275(18):13746–13754. doi: 10.1074/jbc.275.18.13746. [DOI] [PubMed] [Google Scholar]
- McGlade C. J., Ellis C., Reedijk M., Anderson D., Mbamalu G., Reith A. D., Panayotou G., End P., Bernstein A., Kazlauskas A. SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors. Mol Cell Biol. 1992 Mar;12(3):991–997. doi: 10.1128/mcb.12.3.991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- O'Shannessy D. J., Brigham-Burke M., Soneson K. K., Hensley P., Brooks I. Determination of rate and equilibrium binding constants for macromolecular interactions using surface plasmon resonance: use of nonlinear least squares analysis methods. Anal Biochem. 1993 Aug 1;212(2):457–468. doi: 10.1006/abio.1993.1355. [DOI] [PubMed] [Google Scholar]
- Otsu M., Hiles I., Gout I., Fry M. J., Ruiz-Larrea F., Panayotou G., Thompson A., Dhand R., Hsuan J., Totty N. Characterization of two 85 kd proteins that associate with receptor tyrosine kinases, middle-T/pp60c-src complexes, and PI3-kinase. Cell. 1991 Apr 5;65(1):91–104. doi: 10.1016/0092-8674(91)90411-q. [DOI] [PubMed] [Google Scholar]
- Pacold M. E., Suire S., Perisic O., Lara-Gonzalez S., Davis C. T., Walker E. H., Hawkins P. T., Stephens L., Eccleston J. F., Williams R. L. Crystal structure and functional analysis of Ras binding to its effector phosphoinositide 3-kinase gamma. Cell. 2000 Dec 8;103(6):931–943. doi: 10.1016/s0092-8674(00)00196-3. [DOI] [PubMed] [Google Scholar]
- Pons S., Asano T., Glasheen E., Miralpeix M., Zhang Y., Fisher T. L., Myers M. G., Jr, Sun X. J., White M. F. The structure and function of p55PIK reveal a new regulatory subunit for phosphatidylinositol 3-kinase. Mol Cell Biol. 1995 Aug;15(8):4453–4465. doi: 10.1128/mcb.15.8.4453. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rodriguez-Viciana P., Warne P. H., Vanhaesebroeck B., Waterfield M. D., Downward J. Activation of phosphoinositide 3-kinase by interaction with Ras and by point mutation. EMBO J. 1996 May 15;15(10):2442–2451. [PMC free article] [PubMed] [Google Scholar]
- Romoser V., Ball R., Smrcka A. V. Phospholipase C beta2 association with phospholipid interfaces assessed by fluorescence resonance energy transfer. G protein betagamma subunit-mediated translocation is not required for enzyme activation. J Biol Chem. 1996 Oct 11;271(41):25071–25078. doi: 10.1074/jbc.271.41.25071. [DOI] [PubMed] [Google Scholar]
- Stephens L. R., Eguinoa A., Erdjument-Bromage H., Lui M., Cooke F., Coadwell J., Smrcka A. S., Thelen M., Cadwallader K., Tempst P. The G beta gamma sensitivity of a PI3K is dependent upon a tightly associated adaptor, p101. Cell. 1997 Apr 4;89(1):105–114. doi: 10.1016/s0092-8674(00)80187-7. [DOI] [PubMed] [Google Scholar]
- Stephens L. R., Hughes K. T., Irvine R. F. Pathway of phosphatidylinositol(3,4,5)-trisphosphate synthesis in activated neutrophils. Nature. 1991 May 2;351(6321):33–39. doi: 10.1038/351033a0. [DOI] [PubMed] [Google Scholar]
- Stephens L. R., Jackson T. R., Hawkins P. T. Agonist-stimulated synthesis of phosphatidylinositol(3,4,5)-trisphosphate: a new intracellular signalling system? Biochim Biophys Acta. 1993 Oct 7;1179(1):27–75. doi: 10.1016/0167-4889(93)90072-w. [DOI] [PubMed] [Google Scholar]
- Stephens L., Smrcka A., Cooke F. T., Jackson T. R., Sternweis P. C., Hawkins P. T. A novel phosphoinositide 3 kinase activity in myeloid-derived cells is activated by G protein beta gamma subunits. Cell. 1994 Apr 8;77(1):83–93. doi: 10.1016/0092-8674(94)90237-2. [DOI] [PubMed] [Google Scholar]
- Vaziri C., Downes C. P., Macfarlane S. C. Direct labelling of hormone-sensitive phosphoinositides by a plasma-membrane-associated PtdIns synthase in turkey erythrocytes. Biochem J. 1993 Sep 15;294(Pt 3):793–799. doi: 10.1042/bj2940793. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walker E. H., Perisic O., Ried C., Stephens L., Williams R. L. Structural insights into phosphoinositide 3-kinase catalysis and signalling. Nature. 1999 Nov 18;402(6759):313–320. doi: 10.1038/46319. [DOI] [PubMed] [Google Scholar]