Specific activation of p85-p110 phosphatidylinositol 3'-kinase stimulates DNA synthesis by ras- and p70 S6 kinase-dependent pathways (original) (raw)

Abstract

We have developed a polyclonal antibody that activates the heterodimeric p85-p110 phosphatidylinositol (PI) 3'-kinase in vitro and in microinjected cells. Affinity purification revealed that the activating antibody recognized the N-terminal SH2 (NSH2) domain of p85, and the antibody increased the catalytic activity of recombinant p85-p110 dimers threefold in vitro. To study the role of endogenous PI 3'-kinase in intact cells, the activating anti-NSH2 antibody was microinjected into GRC + LR73 cells, a CHO cell derivative selected for tight quiescence during serum withdrawal. Microinjection of anti-NSH2 antibodies increased bromodeoxyuridine (BrdU) incorporation fivefold in quiescent cells and enhanced the response to serum. These data reflect a specific activation of PI 3'-kinase, as the effect was blocked by coinjection of the appropriate antigen (glutathione S-transferase-NSH2 domains from p85 alpha), coinjection of inhibitory anti-p110 antibodies, or treatment of cells with wortmannin. We used the activating antibodies to study signals downstream from PI 3'-kinase. Although treatment of cells with 50 nM rapamycin only partially decreased anti-NSH2-stimulated BrdU incorporation, coinjection with an anti-p70 S6 kinase antibody effectively blocked anti-NSH2-stimulated DNA synthesis. We also found that coinjection of inhibitory anti-ras antibodies blocked both serum- and anti-NSH2-stimulated BrdU incorporation by approximately 60%, and treatment of cells with a specific inhibitor of MEK abolished antibody-stimulated BrdU incorporation. We conclude that selective activation of physiological levels of PI 3'-kinase is sufficient to stimulate DNA synthesis in quiescent cells. PI 3'-kinase-mediated DNA synthesis requires both p70 S6 kinase and the P21ras/MEK pathway.

Full Text

The Full Text of this article is available as a PDF (348.9 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Akimoto K., Takahashi R., Moriya S., Nishioka N., Takayanagi J., Kimura K., Fukui Y., Osada S. i., Mizuno K., Hirai S. i. EGF or PDGF receptors activate atypical PKClambda through phosphatidylinositol 3-kinase. EMBO J. 1996 Feb 15;15(4):788–798. [PMC free article] [PubMed] [Google Scholar]
  2. 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]
  3. Backer J. M., Myers M. G., Jr, Sun X. J., Chin D. J., Shoelson S. E., Miralpeix M., White M. F. Association of IRS-1 with the insulin receptor and the phosphatidylinositol 3'-kinase. Formation of binary and ternary signaling complexes in intact cells. J Biol Chem. 1993 Apr 15;268(11):8204–8212. [PubMed] [Google Scholar]
  4. Betsholtz C., Johnsson A., Heldin C. H., Westermark B. Efficient reversion of simian sarcoma virus-transformation and inhibition of growth factor-induced mitogenesis by suramin. Proc Natl Acad Sci U S A. 1986 Sep;83(17):6440–6444. doi: 10.1073/pnas.83.17.6440. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Brown E. J., Albers M. W., Shin T. B., Ichikawa K., Keith C. T., Lane W. S., Schreiber S. L. A mammalian protein targeted by G1-arresting rapamycin-receptor complex. Nature. 1994 Jun 30;369(6483):756–758. doi: 10.1038/369756a0. [DOI] [PubMed] [Google Scholar]
  6. Cantley L. C., Auger K. R., Carpenter C., Duckworth B., Graziani A., Kapeller R., Soltoff S. Oncogenes and signal transduction. Cell. 1991 Jan 25;64(2):281–302. doi: 10.1016/0092-8674(91)90639-g. [DOI] [PubMed] [Google Scholar]
  7. 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]
  8. Cheatham B., Vlahos C. J., Cheatham L., Wang L., Blenis J., Kahn C. R. Phosphatidylinositol 3-kinase activation is required for insulin stimulation of pp70 S6 kinase, DNA synthesis, and glucose transporter translocation. Mol Cell Biol. 1994 Jul;14(7):4902–4911. doi: 10.1128/mcb.14.7.4902. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Cheatham L., Monfar M., Chou M. M., Blenis J. Structural and functional analysis of pp70S6k. Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11696–11700. doi: 10.1073/pnas.92.25.11696. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Chung J., Grammer T. C., Lemon K. P., Kazlauskas A., Blenis J. PDGF- and insulin-dependent pp70S6k activation mediated by phosphatidylinositol-3-OH kinase. Nature. 1994 Jul 7;370(6484):71–75. doi: 10.1038/370071a0. [DOI] [PubMed] [Google Scholar]
  11. Cross M. J., Stewart A., Hodgkin M. N., Kerr D. J., Wakelam M. J. Wortmannin and its structural analogue demethoxyviridin inhibit stimulated phospholipase A2 activity in Swiss 3T3 cells. Wortmannin is not a specific inhibitor of phosphatidylinositol 3-kinase. J Biol Chem. 1995 Oct 27;270(43):25352–25355. doi: 10.1074/jbc.270.43.25352. [DOI] [PubMed] [Google Scholar]
  12. Davis R. J. The mitogen-activated protein kinase signal transduction pathway. J Biol Chem. 1993 Jul 15;268(20):14553–14556. [PubMed] [Google Scholar]
  13. Escobedo J. A., Navankasattusas S., Kavanaugh W. M., Milfay D., Fried V. A., Williams L. T. cDNA cloning of a novel 85 kd protein that has SH2 domains and regulates binding of PI3-kinase to the PDGF beta-receptor. Cell. 1991 Apr 5;65(1):75–82. doi: 10.1016/0092-8674(91)90409-r. [DOI] [PubMed] [Google Scholar]
  14. Flanagan C. A., Schnieders E. A., Emerick A. W., Kunisawa R., Admon A., Thorner J. Phosphatidylinositol 4-kinase: gene structure and requirement for yeast cell viability. Science. 1993 Nov 26;262(5138):1444–1448. doi: 10.1126/science.8248783. [DOI] [PubMed] [Google Scholar]
  15. Furth M. E., Davis L. J., Fleurdelys B., Scolnick E. M. Monoclonal antibodies to the p21 products of the transforming gene of Harvey murine sarcoma virus and of the cellular ras gene family. J Virol. 1982 Jul;43(1):294–304. doi: 10.1128/jvi.43.1.294-304.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Guinebault C., Payrastre B., Racaud-Sultan C., Mazarguil H., Breton M., Mauco G., Plantavid M., Chap H. Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase. J Cell Biol. 1995 May;129(3):831–842. doi: 10.1083/jcb.129.3.831. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Hara K., Yonezawa K., Sakaue H., Kotani K., Kotani K., Kojima A., Waterfield M. D., Kasuga M. Normal activation of p70 S6 kinase by insulin in cells overexpressing dominant negative 85kD subunit of phosphoinositide 3-kinase. Biochem Biophys Res Commun. 1995 Mar 17;208(2):735–741. doi: 10.1006/bbrc.1995.1399. [DOI] [PubMed] [Google Scholar]
  18. Hartley K. O., Gell D., Smith G. C., Zhang H., Divecha N., Connelly M. A., Admon A., Lees-Miller S. P., Anderson C. W., Jackson S. P. DNA-dependent protein kinase catalytic subunit: a relative of phosphatidylinositol 3-kinase and the ataxia telangiectasia gene product. Cell. 1995 Sep 8;82(5):849–856. doi: 10.1016/0092-8674(95)90482-4. [DOI] [PubMed] [Google Scholar]
  19. Hawkins P. T., Eguinoa A., Qiu R. G., Stokoe D., Cooke F. T., Walters R., Wennström S., Claesson-Welsh L., Evans T., Symons M. PDGF stimulates an increase in GTP-Rac via activation of phosphoinositide 3-kinase. Curr Biol. 1995 Apr 1;5(4):393–403. doi: 10.1016/s0960-9822(95)00080-7. [DOI] [PubMed] [Google Scholar]
  20. 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]
  21. Hu P., Margolis B., Skolnik E. Y., Lammers R., Ullrich A., Schlessinger J. Interaction of phosphatidylinositol 3-kinase-associated p85 with epidermal growth factor and platelet-derived growth factor receptors. Mol Cell Biol. 1992 Mar;12(3):981–990. doi: 10.1128/mcb.12.3.981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. 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]
  23. Hu Q., Klippel A., Muslin A. J., Fantl W. J., Williams L. T. Ras-dependent induction of cellular responses by constitutively active phosphatidylinositol-3 kinase. Science. 1995 Apr 7;268(5207):100–102. doi: 10.1126/science.7701328. [DOI] [PubMed] [Google Scholar]
  24. Jhun B. H., Rose D. W., Seely B. L., Rameh L., Cantley L., Saltiel A. R., Olefsky J. M. Microinjection of the SH2 domain of the 85-kilodalton subunit of phosphatidylinositol 3-kinase inhibits insulin-induced DNA synthesis and c-fos expression. Mol Cell Biol. 1994 Nov;14(11):7466–7475. doi: 10.1128/mcb.14.11.7466. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Joly M., Kazlauskas A., Corvera S. Phosphatidylinositol 3-kinase activity is required at a postendocytic step in platelet-derived growth factor receptor trafficking. J Biol Chem. 1995 Jun 2;270(22):13225–13230. doi: 10.1074/jbc.270.22.13225. [DOI] [PubMed] [Google Scholar]
  26. Kapeller R., Cantley L. C. Phosphatidylinositol 3-kinase. Bioessays. 1994 Aug;16(8):565–576. doi: 10.1002/bies.950160810. [DOI] [PubMed] [Google Scholar]
  27. Kimura K., Hattori S., Kabuyama Y., Shizawa Y., Takayanagi J., Nakamura S., Toki S., Matsuda Y., Onodera K., Fukui Y. Neurite outgrowth of PC12 cells is suppressed by wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase. J Biol Chem. 1994 Jul 22;269(29):18961–18967. [PubMed] [Google Scholar]
  28. Klippel A., Reinhard C., Kavanaugh W. M., Apell G., Escobedo M. A., Williams L. T. Membrane localization of phosphatidylinositol 3-kinase is sufficient to activate multiple signal-transducing kinase pathways. Mol Cell Biol. 1996 Aug;16(8):4117–4127. doi: 10.1128/mcb.16.8.4117. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Kotani K., Yonezawa K., Hara K., Ueda H., Kitamura Y., Sakaue H., Ando A., Chavanieu A., Calas B., Grigorescu F. Involvement of phosphoinositide 3-kinase in insulin- or IGF-1-induced membrane ruffling. EMBO J. 1994 May 15;13(10):2313–2321. doi: 10.1002/j.1460-2075.1994.tb06515.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Kunz J., Henriquez R., Schneider U., Deuter-Reinhard M., Movva N. R., Hall M. N. Target of rapamycin in yeast, TOR2, is an essential phosphatidylinositol kinase homolog required for G1 progression. Cell. 1993 May 7;73(3):585–596. doi: 10.1016/0092-8674(93)90144-f. [DOI] [PubMed] [Google Scholar]
  31. Kuo C. J., Chung J., Fiorentino D. F., Flanagan W. M., Blenis J., Crabtree G. R. Rapamycin selectively inhibits interleukin-2 activation of p70 S6 kinase. Nature. 1992 Jul 2;358(6381):70–73. doi: 10.1038/358070a0. [DOI] [PubMed] [Google Scholar]
  32. Kyriakis J. M., Woodgett J. R., Avruch J. The stress-activated protein kinases. A novel ERK subfamily responsive to cellular stress and inflammatory cytokines. Ann N Y Acad Sci. 1995 Sep 7;766:303–319. doi: 10.1111/j.1749-6632.1995.tb26683.x. [DOI] [PubMed] [Google Scholar]
  33. Lane H. A., Fernandez A., Lamb N. J., Thomas G. p70s6k function is essential for G1 progression. Nature. 1993 May 13;363(6425):170–172. doi: 10.1038/363170a0. [DOI] [PubMed] [Google Scholar]
  34. Martys J. L., Wjasow C., Gangi D. M., Kielian M. C., McGraw T. E., Backer J. M. Wortmannin-sensitive trafficking pathways in Chinese hamster ovary cells. Differential effects on endocytosis and lysosomal sorting. J Biol Chem. 1996 May 3;271(18):10953–10962. doi: 10.1074/jbc.271.18.10953. [DOI] [PubMed] [Google Scholar]
  35. Minden A., Lin A., Claret F. X., Abo A., Karin M. Selective activation of the JNK signaling cascade and c-Jun transcriptional activity by the small GTPases Rac and Cdc42Hs. Cell. 1995 Jun 30;81(7):1147–1157. doi: 10.1016/s0092-8674(05)80019-4. [DOI] [PubMed] [Google Scholar]
  36. Ming X. F., Burgering B. M., Wennström S., Claesson-Welsh L., Heldin C. H., Bos J. L., Kozma S. C., Thomas G. Activation of p70/p85 S6 kinase by a pathway independent of p21ras. Nature. 1994 Sep 29;371(6496):426–429. doi: 10.1038/371426a0. [DOI] [PubMed] [Google Scholar]
  37. Molz L., Chen Y. W., Hirano M., Williams L. T. Cpk is a novel class of Drosophila PtdIns 3-kinase containing a C2 domain. J Biol Chem. 1996 Jun 7;271(23):13892–13899. doi: 10.1074/jbc.271.23.13892. [DOI] [PubMed] [Google Scholar]
  38. Mulcahy L. S., Smith M. R., Stacey D. W. Requirement for ras proto-oncogene function during serum-stimulated growth of NIH 3T3 cells. Nature. 1985 Jan 17;313(5999):241–243. doi: 10.1038/313241a0. [DOI] [PubMed] [Google Scholar]
  39. Nakanishi H., Brewer K. A., Exton J. H. Activation of the zeta isozyme of protein kinase C by phosphatidylinositol 3,4,5-trisphosphate. J Biol Chem. 1993 Jan 5;268(1):13–16. [PubMed] [Google Scholar]
  40. Nakanishi S., Catt K. J., Balla T. A wortmannin-sensitive phosphatidylinositol 4-kinase that regulates hormone-sensitive pools of inositolphospholipids. Proc Natl Acad Sci U S A. 1995 Jun 6;92(12):5317–5321. doi: 10.1073/pnas.92.12.5317. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Nishimura R., Li W., Kashishian A., Mondino A., Zhou M., Cooper J., Schlessinger J. Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor. Mol Cell Biol. 1993 Nov;13(11):6889–6896. doi: 10.1128/mcb.13.11.6889. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Okada T., Kawano Y., Sakakibara T., Hazeki O., Ui M. Essential role of phosphatidylinositol 3-kinase in insulin-induced glucose transport and antilipolysis in rat adipocytes. Studies with a selective inhibitor wortmannin. J Biol Chem. 1994 Feb 4;269(5):3568–3573. [PubMed] [Google Scholar]
  43. 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]
  44. Panayotou G., Bax B., Gout I., Federwisch M., Wroblowski B., Dhand R., Fry M. J., Blundell T. L., Wollmer A., Waterfield M. D. Interaction of the p85 subunit of PI 3-kinase and its N-terminal SH2 domain with a PDGF receptor phosphorylation site: structural features and analysis of conformational changes. EMBO J. 1992 Dec;11(12):4261–4272. doi: 10.1002/j.1460-2075.1992.tb05524.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Pang L., Sawada T., Decker S. J., Saltiel A. R. Inhibition of MAP kinase kinase blocks the differentiation of PC-12 cells induced by nerve growth factor. J Biol Chem. 1995 Jun 9;270(23):13585–13588. doi: 10.1074/jbc.270.23.13585. [DOI] [PubMed] [Google Scholar]
  46. Pleiman C. M., Hertz W. M., Cambier J. C. Activation of phosphatidylinositol-3' kinase by Src-family kinase SH3 binding to the p85 subunit. Science. 1994 Mar 18;263(5153):1609–1612. doi: 10.1126/science.8128248. [DOI] [PubMed] [Google Scholar]
  47. Pollard J. W., Stanners C. P. Characterization of cell lines showing growth control isolated from both the wild type and a leucyl-tRNA synthetase mutant of Chinese hamster ovary cells. J Cell Physiol. 1979 Mar;98(3):571–585. doi: 10.1002/jcp.1040980315. [DOI] [PubMed] [Google Scholar]
  48. 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]
  49. Price D. J., Grove J. R., Calvo V., Avruch J., Bierer B. E. Rapamycin-induced inhibition of the 70-kilodalton S6 protein kinase. Science. 1992 Aug 14;257(5072):973–977. doi: 10.1126/science.1380182. [DOI] [PubMed] [Google Scholar]
  50. Roche S., Koegl M., Courtneidge S. A. The phosphatidylinositol 3-kinase alpha is required for DNA synthesis induced by some, but not all, growth factors. Proc Natl Acad Sci U S A. 1994 Sep 13;91(19):9185–9189. doi: 10.1073/pnas.91.19.9185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Rodriguez-Viciana P., Warne P. H., Dhand R., Vanhaesebroeck B., Gout I., Fry M. J., Waterfield M. D., Downward J. Phosphatidylinositol-3-OH kinase as a direct target of Ras. Nature. 1994 Aug 18;370(6490):527–532. doi: 10.1038/370527a0. [DOI] [PubMed] [Google Scholar]
  52. 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]
  53. Rordorf-Nikolic T., Van Horn D. J., Chen D., White M. F., Backer J. M. Regulation of phosphatidylinositol 3'-kinase by tyrosyl phosphoproteins. Full activation requires occupancy of both SH2 domains in the 85-kDa regulatory subunit. J Biol Chem. 1995 Feb 24;270(8):3662–3666. doi: 10.1074/jbc.270.8.3662. [DOI] [PubMed] [Google Scholar]
  54. Sabatini D. M., Erdjument-Bromage H., Lui M., Tempst P., Snyder S. H. RAFT1: a mammalian protein that binds to FKBP12 in a rapamycin-dependent fashion and is homologous to yeast TORs. Cell. 1994 Jul 15;78(1):35–43. doi: 10.1016/0092-8674(94)90570-3. [DOI] [PubMed] [Google Scholar]
  55. Sabatini D. M., Pierchala B. A., Barrow R. K., Schell M. J., Snyder S. H. The rapamycin and FKBP12 target (RAFT) displays phosphatidylinositol 4-kinase activity. J Biol Chem. 1995 Sep 8;270(36):20875–20878. doi: 10.1074/jbc.270.36.20875. [DOI] [PubMed] [Google Scholar]
  56. Savitsky K., Bar-Shira A., Gilad S., Rotman G., Ziv Y., Vanagaite L., Tagle D. A., Smith S., Uziel T., Sfez S. A single ataxia telangiectasia gene with a product similar to PI-3 kinase. Science. 1995 Jun 23;268(5218):1749–1753. doi: 10.1126/science.7792600. [DOI] [PubMed] [Google Scholar]
  57. Skolnik E. Y., Margolis B., Mohammadi M., Lowenstein E., Fischer R., Drepps A., Ullrich A., Schlessinger J. Cloning of PI3 kinase-associated p85 utilizing a novel method for expression/cloning of target proteins for receptor tyrosine kinases. Cell. 1991 Apr 5;65(1):83–90. doi: 10.1016/0092-8674(91)90410-z. [DOI] [PubMed] [Google Scholar]
  58. Stoyanov B., Volinia S., Hanck T., Rubio I., Loubtchenkov M., Malek D., Stoyanova S., Vanhaesebroeck B., Dhand R., Nürnberg B. Cloning and characterization of a G protein-activated human phosphoinositide-3 kinase. Science. 1995 Aug 4;269(5224):690–693. doi: 10.1126/science.7624799. [DOI] [PubMed] [Google Scholar]
  59. Toker A., Bachelot C., Chen C. S., Falck J. R., Hartwig J. H., Cantley L. C., Kovacsovics T. J. Phosphorylation of the platelet p47 phosphoprotein is mediated by the lipid products of phosphoinositide 3-kinase. J Biol Chem. 1995 Dec 8;270(49):29525–29531. doi: 10.1074/jbc.270.49.29525. [DOI] [PubMed] [Google Scholar]
  60. Toker A., Meyer M., Reddy K. K., Falck J. R., Aneja R., Aneja S., Parra A., Burns D. J., Ballas L. M., Cantley L. C. Activation of protein kinase C family members by the novel polyphosphoinositides PtdIns-3,4-P2 and PtdIns-3,4,5-P3. J Biol Chem. 1994 Dec 23;269(51):32358–32367. [PubMed] [Google Scholar]
  61. Tolias K. F., Cantley L. C., Carpenter C. L. Rho family GTPases bind to phosphoinositide kinases. J Biol Chem. 1995 Jul 28;270(30):17656–17659. doi: 10.1074/jbc.270.30.17656. [DOI] [PubMed] [Google Scholar]
  62. Valius M., Kazlauskas A. Phospholipase C-gamma 1 and phosphatidylinositol 3 kinase are the downstream mediators of the PDGF receptor's mitogenic signal. Cell. 1993 Apr 23;73(2):321–334. doi: 10.1016/0092-8674(93)90232-f. [DOI] [PubMed] [Google Scholar]
  63. Virbasius J. V., Guilherme A., Czech M. P. Mouse p170 is a novel phosphatidylinositol 3-kinase containing a C2 domain. J Biol Chem. 1996 Jun 7;271(23):13304–13307. doi: 10.1074/jbc.271.23.13304. [DOI] [PubMed] [Google Scholar]
  64. Volinia S., Dhand R., Vanhaesebroeck B., MacDougall L. K., Stein R., Zvelebil M. J., Domin J., Panaretou C., Waterfield M. D. A human phosphatidylinositol 3-kinase complex related to the yeast Vps34p-Vps15p protein sorting system. EMBO J. 1995 Jul 17;14(14):3339–3348. doi: 10.1002/j.1460-2075.1995.tb07340.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  65. Weng Q. P., Andrabi K., Klippel A., Kozlowski M. T., Williams L. T., Avruch J. Phosphatidylinositol 3-kinase signals activation of p70 S6 kinase in situ through site-specific p70 phosphorylation. Proc Natl Acad Sci U S A. 1995 Jun 6;92(12):5744–5748. doi: 10.1073/pnas.92.12.5744. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Weng Q. P., Andrabi K., Kozlowski M. T., Grove J. R., Avruch J. Multiple independent inputs are required for activation of the p70 S6 kinase. Mol Cell Biol. 1995 May;15(5):2333–2340. doi: 10.1128/mcb.15.5.2333. [DOI] [PMC free article] [PubMed] [Google Scholar]
  67. Yamauchi K., Holt K., Pessin J. E. Phosphatidylinositol 3-kinase functions upstream of Ras and Raf in mediating insulin stimulation of c-fos transcription. J Biol Chem. 1993 Jul 15;268(20):14597–14600. [PubMed] [Google Scholar]
  68. Yao R., Cooper G. M. Requirement for phosphatidylinositol-3 kinase in the prevention of apoptosis by nerve growth factor. Science. 1995 Mar 31;267(5206):2003–2006. doi: 10.1126/science.7701324. [DOI] [PubMed] [Google Scholar]
  69. Zhang J., Falck J. R., Reddy K. K., Abrams C. S., Zhao W., Rittenhouse S. E. Phosphatidylinositol (3,4,5)-trisphosphate stimulates phosphorylation of pleckstrin in human platelets. J Biol Chem. 1995 Sep 29;270(39):22807–22810. doi: 10.1074/jbc.270.39.22807. [DOI] [PubMed] [Google Scholar]