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J Cell Biol. 1995 March 2; 128(6): 1131–1144.
PMCID: PMC2120410

A novel pool of protein phosphatase 2A is associated with microtubules and is regulated during the cell cycle


Immunofluorescence microscopy revealed the presence of protein phosphatase 2A (PP2A) on microtubules in neuronal and nonneuronal cells. Interphase and mitotic spindle microtubules, as well as centrosomes, were all labeled with antibodies against individual PP2A subunits, showing that the AB alpha C holoenzyme is associated with microtubules. Biochemical analysis showed that PP2A could be reversibly bound to microtubules in vitro and that approximately 75% of the PP2A in cytosolic extracts could interact with microtubules. The activity of microtubule-associated PP2A was differentially regulated during the cell cycle. Enzymatic activity was high during S phase and intermediate during G1, while the activity in G2 and M was 20-fold lower than during S phase. The amount of microtubule-bound PP2A remained constant throughout the cell cycle, implying that cell cycle regulation of its enzymatic activity involves factors other than microtubules. These results raise the possibility that PP2A regulates cell cycle-dependent microtubule functions, such as karyokinesis and membrane transport.

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Selected References

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  • Alexandre H, Van Cauwenberge A, Tsukitani Y, Mulnard J. Pleiotropic effect of okadaic acid on maturing mouse oocytes. Development. 1991 Aug;112(4):971–980. [PubMed]
  • Alfa CE, Booher R, Beach D, Hyams JS. Fission yeast cyclin: subcellular localisation and cell cycle regulation. J Cell Sci Suppl. 1989;12:9–19. [PubMed]
  • Allan VJ, Vale RD. Cell cycle control of microtubule-based membrane transport and tubule formation in vitro. J Cell Biol. 1991 Apr;113(2):347–359. [PMC free article] [PubMed]
  • Bailly E, Dorée M, Nurse P, Bornens M. p34cdc2 is located in both nucleus and cytoplasm; part is centrosomally associated at G2/M and enters vesicles at anaphase. EMBO J. 1989 Dec 20;8(13):3985–3995. [PubMed]
  • Bailly E, Pines J, Hunter T, Bornens M. Cytoplasmic accumulation of cyclin B1 in human cells: association with a detergent-resistant compartment and with the centrosome. J Cell Sci. 1992 Mar;101(Pt 3):529–545. [PubMed]
  • Bloom GS, Luca FC, Vallee RB. Identification of high molecular weight microtubule-associated proteins in anterior pituitary tissue and cells using taxol-dependent purification combined with microtubule-associated protein specific antibodies. Biochemistry. 1985 Jul 16;24(15):4185–4191. [PubMed]
  • Bloom GS, Wagner MC, Pfister KK, Brady ST. Native structure and physical properties of bovine brain kinesin and identification of the ATP-binding subunit polypeptide. Biochemistry. 1988 May 3;27(9):3409–3416. [PubMed]
  • Brewis ND, Street AJ, Prescott AR, Cohen PT. PPX, a novel protein serine/threonine phosphatase localized to centrosomes. EMBO J. 1993 Mar;12(3):987–996. [PubMed]
  • Brown S, Levinson W, Spudich JA. Cytoskeletal elements of chick embryo fibroblasts revealed by detergent extraction. J Supramol Struct. 1976;5(2):119–130. [PubMed]
  • Chen J, Martin BL, Brautigan DL. Regulation of protein serine-threonine phosphatase type-2A by tyrosine phosphorylation. Science. 1992 Aug 28;257(5074):1261–1264. [PubMed]
  • Chen SC, Kramer G, Hardesty B. Isolation and partial characterization of an Mr 60,000 subunit of a type 2A phosphatase from rabbit reticulocytes. J Biol Chem. 1989 May 5;264(13):7267–7275. [PubMed]
  • Cohen P. The structure and regulation of protein phosphatases. Annu Rev Biochem. 1989;58:453–508. [PubMed]
  • Cohen P, Klumpp S, Schelling DL. An improved procedure for identifying and quantitating protein phosphatases in mammalian tissues. FEBS Lett. 1989 Jul 3;250(2):596–600. [PubMed]
  • Drewes G, Mandelkow EM, Baumann K, Goris J, Merlevede W, Mandelkow E. Dephosphorylation of tau protein and Alzheimer paired helical filaments by calcineurin and phosphatase-2A. FEBS Lett. 1993 Dec 28;336(3):425–432. [PubMed]
  • Eriksson JE, Brautigan DL, Vallee R, Olmsted J, Fujiki H, Goldman RD. Cytoskeletal integrity in interphase cells requires protein phosphatase activity. Proc Natl Acad Sci U S A. 1992 Nov 15;89(22):11093–11097. [PubMed]
  • Ferrigno P, Langan TA, Cohen P. Protein phosphatase 2A1 is the major enzyme in vertebrate cell extracts that dephosphorylates several physiological substrates for cyclin-dependent protein kinases. Mol Biol Cell. 1993 Jul;4(7):669–677. [PMC free article] [PubMed]
  • Félix MA, Cohen P, Karsenti E. Cdc2 H1 kinase is negatively regulated by a type 2A phosphatase in the Xenopus early embryonic cell cycle: evidence from the effects of okadaic acid. EMBO J. 1990 Mar;9(3):675–683. [PubMed]
  • Floer M, Stock J. Carboxyl methylation of protein phosphatase 2A from Xenopus eggs is stimulated by cAMP and inhibited by okadaic acid. Biochem Biophys Res Commun. 1994 Jan 14;198(1):372–379. [PubMed]
  • Gallant P, Nigg EA. Cyclin B2 undergoes cell cycle-dependent nuclear translocation and, when expressed as a non-destructible mutant, causes mitotic arrest in HeLa cells. J Cell Biol. 1992 Apr;117(1):213–224. [PMC free article] [PubMed]
  • Gliksman NR, Parsons SF, Salmon ED. Okadaic acid induces interphase to mitotic-like microtubule dynamic instability by inactivating rescue. J Cell Biol. 1992 Dec;119(5):1271–1276. [PMC free article] [PubMed]
  • Goedert M. Tau protein and the neurofibrillary pathology of Alzheimer's disease. Trends Neurosci. 1993 Nov;16(11):460–465. [PubMed]
  • Gotoh Y, Nishida E, Matsuda S, Shiina N, Kosako H, Shiokawa K, Akiyama T, Ohta K, Sakai H. In vitro effects on microtubule dynamics of purified Xenopus M phase-activated MAP kinase. Nature. 1991 Jan 17;349(6306):251–254. [PubMed]
  • Gurland G, Gundersen GG. Protein phosphatase inhibitors induce the selective breakdown of stable microtubules in fibroblasts and epithelial cells. Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):8827–8831. [PubMed]
  • Hamm-Alvarez SF, Kim PY, Sheetz MP. Regulation of vesicle transport in CV-1 cells and extracts. J Cell Sci. 1993 Nov;106(Pt 3):955–966. [PubMed]
  • Healy AM, Zolnierowicz S, Stapleton AE, Goebl M, DePaoli-Roach AA, Pringle JR. CDC55, a Saccharomyces cerevisiae gene involved in cellular morphogenesis: identification, characterization, and homology to the B subunit of mammalian type 2A protein phosphatase. Mol Cell Biol. 1991 Nov;11(11):5767–5780. [PMC free article] [PubMed]
  • Hill M, Hillova J, Mariage-Samson R, Fasciotto B, Krsmanovic V. Ability of mammalian fibroblasts to grow in synthetic medium containing neither serum nor exogenously added macromolecules. In Vitro Cell Dev Biol. 1989 Jan;25(1):49–56. [PubMed]
  • Jakes S, Mellgren RL, Schlender KK. Isolation and characterization of an inhibitor-sensitive and a polycation-stimulated protein phosphatase from rat liver nuclei. Biochim Biophys Acta. 1986 Aug 29;888(1):135–142. [PubMed]
  • Kamibayashi C, Estes R, Slaughter C, Mumby MC. Subunit interactions control protein phosphatase 2A. Effects of limited proteolysis, N-ethylmaleimide, and heparin on the interaction of the B subunit. J Biol Chem. 1991 Jul 15;266(20):13251–13260. [PubMed]
  • Kamibayashi C, Lickteig RL, Estes R, Walter G, Mumby MC. Expression of the A subunit of protein phosphatase 2A and characterization of its interactions with the catalytic and regulatory subunits. J Biol Chem. 1992 Oct 25;267(30):21864–21872. [PubMed]
  • Kamibayashi C, Estes R, Lickteig RL, Yang SI, Craft C, Mumby MC. Comparison of heterotrimeric protein phosphatase 2A containing different B subunits. J Biol Chem. 1994 Aug 5;269(31):20139–20148. [PubMed]
  • Karsenti E. Mitotic spindle morphogenesis in animal cells. Semin Cell Biol. 1991 Aug;2(4):251–260. [PubMed]
  • Kellogg DR, Moritz M, Alberts BM. The centrosome and cellular organization. Annu Rev Biochem. 1994;63:639–674. [PubMed]
  • Kinoshita N, Ohkura H, Yanagida M. Distinct, essential roles of type 1 and 2A protein phosphatases in the control of the fission yeast cell division cycle. Cell. 1990 Oct 19;63(2):405–415. [PubMed]
  • Kinoshita N, Yamano H, Niwa H, Yoshida T, Yanagida M. Negative regulation of mitosis by the fission yeast protein phosphatase ppa2. Genes Dev. 1993 Jun;7(6):1059–1071. [PubMed]
  • Kuret J, Bell H, Cohen P. Identification of high levels of protein phosphatase-1 in rat liver nuclei. FEBS Lett. 1986 Jul 28;203(2):197–202. [PubMed]
  • Lee TH, Solomon MJ, Mumby MC, Kirschner MW. INH, a negative regulator of MPF, is a form of protein phosphatase 2A. Cell. 1991 Jan 25;64(2):415–423. [PubMed]
  • Ludlow JW. Selective ability of S-phase cell extracts to dephosphorylate SV40 large T antigen in vitro. Oncogene. 1992 May;7(5):1011–1014. [PubMed]
  • Maldonado-Codina G, Glover DM. Cyclins A and B associate with chromatin and the polar regions of spindles, respectively, and do not undergo complete degradation at anaphase in syncytial Drosophila embryos. J Cell Biol. 1992 Feb;116(4):967–976. [PMC free article] [PubMed]
  • Mayer-Jaekel RE, Ohkura H, Gomes R, Sunkel CE, Baumgartner S, Hemmings BA, Glover DM. The 55 kd regulatory subunit of Drosophila protein phosphatase 2A is required for anaphase. Cell. 1993 Feb 26;72(4):621–633. [PubMed]
  • McIlvain JM, Jr, Burkhardt JK, Hamm-Alvarez S, Argon Y, Sheetz MP. Regulation of kinesin activity by phosphorylation of kinesin-associated proteins. J Biol Chem. 1994 Jul 22;269(29):19176–19182. [PubMed]
  • Mumby MC, Green DD, Russell KL. Structural characterization of cardiac protein phosphatase with a monoclonal antibody. Evidence that the Mr = 38,000 phosphatase is the catalytic subunit of the native enzyme(s). J Biol Chem. 1985 Nov 5;260(25):13763–13770. [PubMed]
  • Mumby MC, Russell KL, Garrard LJ, Green DD. Cardiac contractile protein phosphatases. Purification of two enzyme forms and their characterization with subunit-specific antibodies. J Biol Chem. 1987 May 5;262(13):6257–6265. [PubMed]
  • Mumby MC, Walter G. Protein serine/threonine phosphatases: structure, regulation, and functions in cell growth. Physiol Rev. 1993 Oct;73(4):673–699. [PubMed]
  • Norbury C, Nurse P. Animal cell cycles and their control. Annu Rev Biochem. 1992;61:441–470. [PubMed]
  • O'Callahan CM, Ptasienski J, Hosey MM. Phosphorylation of the 165-kDa dihydropyridine/phenylalkylamine receptor from skeletal muscle by protein kinase C. J Biol Chem. 1988 Nov 25;263(33):17342–17349. [PubMed]
  • Ookata K, Hisanaga S, Okano T, Tachibana K, Kishimoto T. Relocation and distinct subcellular localization of p34cdc2-cyclin B complex at meiosis reinitiation in starfish oocytes. EMBO J. 1992 May;11(5):1763–1772. [PubMed]
  • Ookata K, Hisanaga S, Okumura E, Kishimoto T. Association of p34cdc2/cyclin B complex with microtubules in starfish oocytes. J Cell Sci. 1993 Aug;105(Pt 4):873–881. [PubMed]
  • Osborn M, Weber K. The display of microtubules in transformed cells. Cell. 1977 Nov;12(3):561–571. [PubMed]
  • Pines J, Hunter T. Human cyclins A and B1 are differentially located in the cell and undergo cell cycle-dependent nuclear transport. J Cell Biol. 1991 Oct;115(1):1–17. [PMC free article] [PubMed]
  • Riabowol K, Draetta G, Brizuela L, Vandre D, Beach D. The cdc2 kinase is a nuclear protein that is essential for mitosis in mammalian cells. Cell. 1989 May 5;57(3):393–401. [PubMed]
  • Ruediger R, Van Wart Hood JE, Mumby M, Walter G. Constant expression and activity of protein phosphatase 2A in synchronized cells. Mol Cell Biol. 1991 Aug;11(8):4282–4285. [PMC free article] [PubMed]
  • Shenolikar S, Nairn AC. Protein phosphatases: recent progress. Adv Second Messenger Phosphoprotein Res. 1991;23:1–121. [PubMed]
  • Solomon F. Direct identification of microtubule-associated proteins by selective extraction of cultured cells. Methods Enzymol. 1986;134:139–147. [PubMed]
  • Sontag E, Fedorov S, Kamibayashi C, Robbins D, Cobb M, Mumby M. The interaction of SV40 small tumor antigen with protein phosphatase 2A stimulates the map kinase pathway and induces cell proliferation. Cell. 1993 Dec 3;75(5):887–897. [PubMed]
  • Spudich JA, Watt S. The regulation of rabbit skeletal muscle contraction. I. Biochemical studies of the interaction of the tropomyosin-troponin complex with actin and the proteolytic fragments of myosin. J Biol Chem. 1971 Aug 10;246(15):4866–4871. [PubMed]
  • Usui H, Imazu M, Maeta K, Tsukamoto H, Azuma K, Takeda M. Three distinct forms of type 2A protein phosphatase in human erythrocyte cytosol. J Biol Chem. 1988 Mar 15;263(8):3752–3761. [PubMed]
  • Vallee RB. A taxol-dependent procedure for the isolation of microtubules and microtubule-associated proteins (MAPs). J Cell Biol. 1982 Feb;92(2):435–442. [PMC free article] [PubMed]
  • Vallee RB, Bloom GS. Isolation of sea urchin egg microtubules with taxol and identification of mitotic spindle microtubule-associated proteins with monoclonal antibodies. Proc Natl Acad Sci U S A. 1983 Oct;80(20):6259–6263. [PubMed]
  • Vandre DD, Davis FM, Rao PN, Borisy GG. Phosphoproteins are components of mitotic microtubule organizing centers. Proc Natl Acad Sci U S A. 1984 Jul;81(14):4439–4443. [PubMed]
  • Vandré DD, Wills VL. Inhibition of mitosis by okadaic acid: possible involvement of a protein phosphatase 2A in the transition from metaphase to anaphase. J Cell Sci. 1992 Jan;101(Pt 1):79–91. [PubMed]
  • Verde F, Dogterom M, Stelzer E, Karsenti E, Leibler S. Control of microtubule dynamics and length by cyclin A- and cyclin B-dependent kinases in Xenopus egg extracts. J Cell Biol. 1992 Sep;118(5):1097–1108. [PMC free article] [PubMed]
  • Verde F, Labbé JC, Dorée M, Karsenti E. Regulation of microtubule dynamics by cdc2 protein kinase in cell-free extracts of Xenopus eggs. Nature. 1990 Jan 18;343(6255):233–238. [PubMed]
  • Verlhac MH, de Pennart H, Maro B, Cobb MH, Clarke HJ. MAP kinase becomes stably activated at metaphase and is associated with microtubule-organizing centers during meiotic maturation of mouse oocytes. Dev Biol. 1993 Aug;158(2):330–340. [PubMed]
  • Virshup DM, Kauffman MG, Kelly TJ. Activation of SV40 DNA replication in vitro by cellular protein phosphatase 2A. EMBO J. 1989 Dec 1;8(12):3891–3898. [PubMed]
  • Waelkens E, Goris J, Merlevede W. Purification and properties of polycation-stimulated phosphorylase phosphatases from rabbit skeletal muscle. J Biol Chem. 1987 Jan 25;262(3):1049–1059. [PubMed]
  • Wynford-Thomas D, Bond JA, Paterson H. Suppression of transformation and immortality in human/Chinese hamster fibroblast hybrids--a model for suppressor gene isolation. Int J Cancer. 1989 Feb 15;43(2):293–299. [PubMed]
  • Xie H, Clarke S. Protein phosphatase 2A is reversibly modified by methyl esterification at its C-terminal leucine residue in bovine brain. J Biol Chem. 1994 Jan 21;269(3):1981–1984. [PubMed]
  • Yamashita K, Yasuda H, Pines J, Yasumoto K, Nishitani H, Ohtsubo M, Hunter T, Sugimura T, Nishimoto T. Okadaic acid, a potent inhibitor of type 1 and type 2A protein phosphatases, activates cdc2/H1 kinase and transiently induces a premature mitosis-like state in BHK21 cells. EMBO J. 1990 Dec;9(13):4331–4338. [PubMed]

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