Abstract
The regulation of protein kinase C (PKC)zeta in relation to its turnover, cell growth and transformation was investigated in Rat2 fibroblasts by over-expressing wild-type or mutant forms of PKCzeta. Deletion of the pseudosubstrate site (PSS) produced the most active mutant (PKCzeta Delta PSS), but mutants designed to mimic phosphorylated PKCzeta had lower specific activities in an in vitro assay. The mutant lacking phosphorylation at the Thr-560 site (T560A) had similar specific activity to wild-type PKCzeta. The T560A mutant also protected PKCzeta against proteolysis, whereas phosphorylation at Thr-410 targeted it towards proteosomal degradation. Blocking proteosomal degradation with lactacystin caused the accumulation of full-length PKCzeta Delta PSS, T410E, PKCzeta Delta PSS T410/560E, PKCzeta and T560A. Expressed PKCzeta activity was paralleled by extracellular-regulated protein kinase activation, increased cell division, serum-independent growth and focus formation. These foci were seen for cells expressing higher PKCzeta activity (PKCzeta Delta PSS, PKCzeta Delta PSS T410/560E and T560A mutants), but these fibroblasts did not show significant anchorage-independent growth. This work provides novel information concerning the role of the PSS and phosphorylation sites in regulating the activity and turnover of an atypical PKC and shows how this activity can induce cell transformation with respect to focus formation.
Full Text
The Full Text of this article is available as a PDF (408.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- 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]
- Balendran A., Hare G. R., Kieloch A., Williams M. R., Alessi D. R. Further evidence that 3-phosphoinositide-dependent protein kinase-1 (PDK1) is required for the stability and phosphorylation of protein kinase C (PKC) isoforms. FEBS Lett. 2000 Nov 10;484(3):217–223. doi: 10.1016/s0014-5793(00)02162-1. [DOI] [PubMed] [Google Scholar]
- Berra E., Diaz-Meco M. T., Dominguez I., Municio M. M., Sanz L., Lozano J., Chapkin R. S., Moscat J. Protein kinase C zeta isoform is critical for mitogenic signal transduction. Cell. 1993 Aug 13;74(3):555–563. doi: 10.1016/0092-8674(93)80056-k. [DOI] [PubMed] [Google Scholar]
- Berra E., Municio M. M., Sanz L., Frutos S., Diaz-Meco M. T., Moscat J. Positioning atypical protein kinase C isoforms in the UV-induced apoptotic signaling cascade. Mol Cell Biol. 1997 Aug;17(8):4346–4354. doi: 10.1128/mcb.17.8.4346. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bornancin F., Parker P. J. Phosphorylation of protein kinase C-alpha on serine 657 controls the accumulation of active enzyme and contributes to its phosphatase-resistant state. J Biol Chem. 1997 Feb 7;272(6):3544–3549. doi: 10.1074/jbc.272.6.3544. [DOI] [PubMed] [Google Scholar]
- Bornancin F., Parker P. J. Phosphorylation of threonine 638 critically controls the dephosphorylation and inactivation of protein kinase Calpha. Curr Biol. 1996 Sep 1;6(9):1114–1123. doi: 10.1016/s0960-9822(02)70678-7. [DOI] [PubMed] [Google Scholar]
- Castagna M., Takai Y., Kaibuchi K., Sano K., Kikkawa U., Nishizuka Y. Direct activation of calcium-activated, phospholipid-dependent protein kinase by tumor-promoting phorbol esters. J Biol Chem. 1982 Jul 10;257(13):7847–7851. [PubMed] [Google Scholar]
- Cazaubon S. M., Parker P. J. Identification of the phosphorylated region responsible for the permissive activation of protein kinase C. J Biol Chem. 1993 Aug 15;268(23):17559–17563. [PubMed] [Google Scholar]
- Cazaubon S., Bornancin F., Parker P. J. Threonine-497 is a critical site for permissive activation of protein kinase C alpha. Biochem J. 1994 Jul 15;301(Pt 2):443–448. doi: 10.1042/bj3010443. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chou M. M., Hou W., Johnson J., Graham L. K., Lee M. H., Chen C. S., Newton A. C., Schaffhausen B. S., Toker A. Regulation of protein kinase C zeta by PI 3-kinase and PDK-1. Curr Biol. 1998 Sep 24;8(19):1069–1077. doi: 10.1016/s0960-9822(98)70444-0. [DOI] [PubMed] [Google Scholar]
- Clark G. J., Cox A. D., Graham S. M., Der C. J. Biological assays for Ras transformation. Methods Enzymol. 1995;255:395–412. doi: 10.1016/s0076-6879(95)55042-9. [DOI] [PubMed] [Google Scholar]
- Coussens L., Parker P. J., Rhee L., Yang-Feng T. L., Chen E., Waterfield M. D., Francke U., Ullrich A. Multiple, distinct forms of bovine and human protein kinase C suggest diversity in cellular signaling pathways. Science. 1986 Aug 22;233(4766):859–866. doi: 10.1126/science.3755548. [DOI] [PubMed] [Google Scholar]
- Dekker L. V., McIntyre P., Parker P. J. Altered substrate selectivity of PKC-eta pseudosubstrate site mutants. FEBS Lett. 1993 Aug 23;329(1-2):129–133. doi: 10.1016/0014-5793(93)80208-c. [DOI] [PubMed] [Google Scholar]
- Diaz-Meco M. T., Berra E., Municio M. M., Sanz L., Lozano J., Dominguez I., Diaz-Golpe V., Lain de Lera M. T., Alcamí J., Payá C. V. A dominant negative protein kinase C zeta subspecies blocks NF-kappa B activation. Mol Cell Biol. 1993 Aug;13(8):4770–4775. doi: 10.1128/mcb.13.8.4770. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dutil E. M., Toker A., Newton A. C. Regulation of conventional protein kinase C isozymes by phosphoinositide-dependent kinase 1 (PDK-1). Curr Biol. 1998 Dec 17;8(25):1366–1375. doi: 10.1016/s0960-9822(98)00017-7. [DOI] [PubMed] [Google Scholar]
- Edwards A. S., Newton A. C. Phosphorylation at conserved carboxyl-terminal hydrophobic motif regulates the catalytic and regulatory domains of protein kinase C. J Biol Chem. 1997 Jul 18;272(29):18382–18390. doi: 10.1074/jbc.272.29.18382. [DOI] [PubMed] [Google Scholar]
- Feng X., Hannun Y. A. An essential role for autophosphorylation in the dissociation of activated protein kinase C from the plasma membrane. J Biol Chem. 1998 Oct 9;273(41):26870–26874. doi: 10.1074/jbc.273.41.26870. [DOI] [PubMed] [Google Scholar]
- Flint A. J., Paladini R. D., Koshland D. E., Jr Autophosphorylation of protein kinase C at three separated regions of its primary sequence. Science. 1990 Jul 27;249(4967):408–411. doi: 10.1126/science.2377895. [DOI] [PubMed] [Google Scholar]
- Hansra G., Bornancin F., Whelan R., Hemmings B. A., Parker P. J. 12-O-Tetradecanoylphorbol-13-acetate-induced dephosphorylation of protein kinase Calpha correlates with the presence of a membrane-associated protein phosphatase 2A heterotrimer. J Biol Chem. 1996 Dec 20;271(51):32785–32788. doi: 10.1074/jbc.271.51.32785. [DOI] [PubMed] [Google Scholar]
- Hansra G., Garcia-Paramio P., Prevostel C., Whelan R. D., Bornancin F., Parker P. J. Multisite dephosphorylation and desensitization of conventional protein kinase C isotypes. Biochem J. 1999 Sep 1;342(Pt 2):337–344. [PMC free article] [PubMed] [Google Scholar]
- House C., Kemp B. E. Protein kinase C contains a pseudosubstrate prototope in its regulatory domain. Science. 1987 Dec 18;238(4834):1726–1728. doi: 10.1126/science.3686012. [DOI] [PubMed] [Google Scholar]
- Jasinska R., Zhang Q. X., Pilquil C., Singh I., Xu J., Dewald J., Dillon D. A., Berthiaume L. G., Carman G. M., Waggoner D. W. Lipid phosphate phosphohydrolase-1 degrades exogenous glycerolipid and sphingolipid phosphate esters. Biochem J. 1999 Jun 15;340(Pt 3):677–686. [PMC free article] [PubMed] [Google Scholar]
- Keranen L. M., Dutil E. M., Newton A. C. Protein kinase C is regulated in vivo by three functionally distinct phosphorylations. Curr Biol. 1995 Dec 1;5(12):1394–1403. doi: 10.1016/s0960-9822(95)00277-6. [DOI] [PubMed] [Google Scholar]
- Khosravi-Far R., White M. A., Westwick J. K., Solski P. A., Chrzanowska-Wodnicka M., Van Aelst L., Wigler M. H., Der C. J. Oncogenic Ras activation of Raf/mitogen-activated protein kinase-independent pathways is sufficient to cause tumorigenic transformation. Mol Cell Biol. 1996 Jul;16(7):3923–3933. doi: 10.1128/mcb.16.7.3923. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Le Good J. A., Ziegler W. H., Parekh D. B., Alessi D. R., Cohen P., Parker P. J. Protein kinase C isotypes controlled by phosphoinositide 3-kinase through the protein kinase PDK1. Science. 1998 Sep 25;281(5385):2042–2045. doi: 10.1126/science.281.5385.2042. [DOI] [PubMed] [Google Scholar]
- Lee H. W., Smith L., Pettit G. R., Vinitsky A., Smith J. B. Ubiquitination of protein kinase C-alpha and degradation by the proteasome. J Biol Chem. 1996 Aug 30;271(35):20973–20976. [PubMed] [Google Scholar]
- Li W., Zhang J., Bottaro D. P., Pierce J. H. Identification of serine 643 of protein kinase C-delta as an important autophosphorylation site for its enzymatic activity. J Biol Chem. 1997 Sep 26;272(39):24550–24555. doi: 10.1074/jbc.272.39.24550. [DOI] [PubMed] [Google Scholar]
- Martin A., Duffy P. A., Liossis C., Gomez-Muñoz A., O'Brien L., Stone J. C., Brindley D. N. Increased concentrations of phosphatidate, diacylglycerol and ceramide in ras- and tyrosine kinase (fps)-transformed fibroblasts. Oncogene. 1997 Apr 3;14(13):1571–1580. doi: 10.1038/sj.onc.1200987. [DOI] [PubMed] [Google Scholar]
- Mellor H., Flynn P., Nobes C. D., Hall A., Parker P. J. PRK1 is targeted to endosomes by the small GTPase, RhoB. J Biol Chem. 1998 Feb 27;273(9):4811–4814. doi: 10.1074/jbc.273.9.4811. [DOI] [PubMed] [Google Scholar]
- Newton A. C. Regulation of protein kinase C. Curr Opin Cell Biol. 1997 Apr;9(2):161–167. doi: 10.1016/s0955-0674(97)80058-0. [DOI] [PubMed] [Google Scholar]
- Ono Y., Fujii T., Ogita K., Kikkawa U., Igarashi K., Nishizuka Y. Protein kinase C zeta subspecies from rat brain: its structure, expression, and properties. Proc Natl Acad Sci U S A. 1989 May;86(9):3099–3103. doi: 10.1073/pnas.86.9.3099. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ono Y., Kikkawa U., Ogita K., Fujii T., Kurokawa T., Asaoka Y., Sekiguchi K., Ase K., Igarashi K., Nishizuka Y. Expression and properties of two types of protein kinase C: alternative splicing from a single gene. Science. 1987 May 29;236(4805):1116–1120. doi: 10.1126/science.3576226. [DOI] [PubMed] [Google Scholar]
- Orr J. W., Newton A. C. Interaction of protein kinase C with phosphatidylserine. 2. Specificity and regulation. Biochemistry. 1992 May 19;31(19):4667–4673. doi: 10.1021/bi00134a019. [DOI] [PubMed] [Google Scholar]
- Orr J. W., Newton A. C. Intrapeptide regulation of protein kinase C. J Biol Chem. 1994 Mar 18;269(11):8383–8387. [PubMed] [Google Scholar]
- Orr J. W., Newton A. C. Requirement for negative charge on "activation loop" of protein kinase C. J Biol Chem. 1994 Nov 4;269(44):27715–27718. [PubMed] [Google Scholar]
- Palmer R. H., Dekker L. V., Woscholski R., Le Good J. A., Gigg R., Parker P. J. Activation of PRK1 by phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate. A comparison with protein kinase C isotypes. J Biol Chem. 1995 Sep 22;270(38):22412–22416. doi: 10.1074/jbc.270.38.22412. [DOI] [PubMed] [Google Scholar]
- Parekh D. B., Ziegler W., Parker P. J. Multiple pathways control protein kinase C phosphorylation. EMBO J. 2000 Feb 15;19(4):496–503. doi: 10.1093/emboj/19.4.496. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Parker P. J., Coussens L., Totty N., Rhee L., Young S., Chen E., Stabel S., Waterfield M. D., Ullrich A. The complete primary structure of protein kinase C--the major phorbol ester receptor. Science. 1986 Aug 22;233(4766):853–859. doi: 10.1126/science.3755547. [DOI] [PubMed] [Google Scholar]
- Prevostel C., Alice V., Joubert D., Parker P. J. Protein kinase C(alpha) actively downregulates through caveolae-dependent traffic to an endosomal compartment. J Cell Sci. 2000 Jul;113(Pt 14):2575–2584. doi: 10.1242/jcs.113.14.2575. [DOI] [PubMed] [Google Scholar]
- Qiu R. G., Abo A., Steven Martin G. A human homolog of the C. elegans polarity determinant Par-6 links Rac and Cdc42 to PKCzeta signaling and cell transformation. Curr Biol. 2000 Jun 15;10(12):697–707. doi: 10.1016/s0960-9822(00)00535-2. [DOI] [PubMed] [Google Scholar]
- Schönwasser D. C., Marais R. M., Marshall C. J., Parker P. J. Activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway by conventional, novel, and atypical protein kinase C isotypes. Mol Cell Biol. 1998 Feb;18(2):790–798. doi: 10.1128/mcb.18.2.790. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith L., Chen L., Reyland M. E., DeVries T. A., Talanian R. V., Omura S., Smith J. B. Activation of atypical protein kinase C zeta by caspase processing and degradation by the ubiquitin-proteasome system. J Biol Chem. 2000 Dec 22;275(51):40620–40627. doi: 10.1074/jbc.M908517199. [DOI] [PubMed] [Google Scholar]
- Standaert M. L., Bandyopadhyay G., Kanoh Y., Sajan M. P., Farese R. V. Insulin and PIP3 activate PKC-zeta by mechanisms that are both dependent and independent of phosphorylation of activation loop (T410) and autophosphorylation (T560) sites. Biochemistry. 2001 Jan 9;40(1):249–255. doi: 10.1021/bi0018234. [DOI] [PubMed] [Google Scholar]
- Tsutakawa S. E., Medzihradszky K. F., Flint A. J., Burlingame A. L., Koshland D. E., Jr Determination of in vivo phosphorylation sites in protein kinase C. J Biol Chem. 1995 Nov 10;270(45):26807–26812. doi: 10.1074/jbc.270.45.26807. [DOI] [PubMed] [Google Scholar]
- Ways D. K., Posekany K., deVente J., Garris T., Chen J., Hooker J., Qin W., Cook P., Fletcher D., Parker P. Overexpression of protein kinase C-zeta stimulates leukemic cell differentiation. Cell Growth Differ. 1994 Nov;5(11):1195–1203. [PubMed] [Google Scholar]
- Wooten M. W., Zhou G., Seibenhener M. L., Coleman E. S. A role for zeta protein kinase C in nerve growth factor-induced differentiation of PC12 cells. Cell Growth Differ. 1994 Apr;5(4):395–403. [PubMed] [Google Scholar]
- Yamanishi J., Takai Y., Kaibuchi K., Sano K., Castagna M., Nishizuka Y. Synergistic functions of phorbol ester and calcium in serotonin release from human platelets. Biochem Biophys Res Commun. 1983 Apr 29;112(2):778–786. doi: 10.1016/0006-291x(83)91529-2. [DOI] [PubMed] [Google Scholar]
- Ziegler W. H., Parekh D. B., Le Good J. A., Whelan R. D., Kelly J. J., Frech M., Hemmings B. A., Parker P. J. Rapamycin-sensitive phosphorylation of PKC on a carboxy-terminal site by an atypical PKC complex. Curr Biol. 1999 May 20;9(10):522–529. doi: 10.1016/s0960-9822(99)80236-x. [DOI] [PubMed] [Google Scholar]
