Gene Symbol: SIT4
Description: type 2A-related serine/threonine-protein phosphatase SIT4
Alias: PPH1, type 2A-related serine/threonine-protein phosphatase SIT4
Species: Saccharomyces cerevisiae S288c

Top Publications

  1. Rohde J, Campbell S, Zurita Martinez S, Cutler N, Ashe M, Cardenas M. TOR controls transcriptional and translational programs via Sap-Sit4 protein phosphatase signaling effectors. Mol Cell Biol. 2004;24:8332-41 pubmed
    ..In the budding yeast Saccharomyces cerevisiae, the PP2A-related phosphatase Sit4 together with its regulatory subunit Tap42 mediates several Tor signaling events...
  2. Douville J, David J, Fortier P, Ramotar D. The yeast phosphotyrosyl phosphatase activator protein, yPtpa1/Rrd1, interacts with Sit4 phosphatase to mediate resistance to 4-nitroquinoline-1-oxide and UVA. Curr Genet. 2004;46:72-81 pubmed
    ..We show that this mutant is defective in the SIT4 gene encoding a catalytic subunit of the PP2A phosphatases and that sit4Delta mutants exhibit hypersensitivity to 4-..
  3. Mehlgarten C, Jablonowski D, Breunig K, Stark M, Schaffrath R. Elongator function depends on antagonistic regulation by casein kinase Hrr25 and protein phosphatase Sit4. Mol Microbiol. 2009;73:869-81 pubmed publisher
    ..Thus, hyperphosphorylation of Elp1 due to inactivation of protein phosphatase Sit4 correlates with Elongator-minus phenotypes including resistance towards zymocin, a tRNase cleaving anticodons of ..
  4. González A, Ruiz A, Casamayor A, Arino J. Normal function of the yeast TOR pathway requires the type 2C protein phosphatase Ptc1. Mol Cell Biol. 2009;29:2876-88 pubmed publisher
    ..Interestingly, this decrease is abolished in the absence of the Sit4 phosphatase...
  5. Miranda M, Masuda C, Ferreira Pereira A, Carvajal E, Ghislain M, Montero Lomeli M. The serine/threonine protein phosphatase Sit4p activates multidrug resistance in Saccharomyces cerevisiae. FEMS Yeast Res. 2010;10:674-86 pubmed publisher
    ..The multidrug sensitivity of sit4 mutant cells is suppressed by the PDR1-3 mutant allele, which encodes a hyperactive form of Pdr1p...
  6. Mitchell D, Sprague G. The phosphotyrosyl phosphatase activator, Ncs1p (Rrd1p), functions with Cla4p to regulate the G(2)/M transition in Saccharomyces cerevisiae. Mol Cell Biol. 2001;21:488-500 pubmed
    ..Genetic and biochemical evidence suggested that the phosphatase Sit4p is a target for Ncs1p. First, CLA4 and SIT4 were synthetically lethal...
  7. Sutton A, Immanuel D, Arndt K. The SIT4 protein phosphatase functions in late G1 for progression into S phase. Mol Cell Biol. 1991;11:2133-48 pubmed
    Saccharomyces cerevisiae strains containing temperature-sensitive mutations in the SIT4 protein phosphatase arrest in late G1 at the nonpermissive temperature...
  8. Jablonowski D, Täubert J, Bär C, Stark M, Schaffrath R. Distinct subsets of Sit4 holophosphatases are required for inhibition of Saccharomyces cerevisiae growth by rapamycin and zymocin. Eukaryot Cell. 2009;8:1637-47 pubmed publisher
    Protein phosphatase Sit4 is required for growth inhibition of Saccharomyces cerevisiae by the antifungals rapamycin and zymocin. Here, we show that the rapamycin effector Tap42, which interacts with Sit4, is dispensable for zymocin action...
  9. Zheng Y, Jiang Y. The yeast phosphotyrosyl phosphatase activator is part of the Tap42-phosphatase complexes. Mol Biol Cell. 2005;16:2119-27 pubmed
    ..We demonstrate a specific interaction of Rrd1 with the Tap42-Sit4 complex and that of Rrd2 with the Tap42-PP2Ac complex...

More Information


  1. Stark M. Yeast protein serine/threonine phosphatases: multiple roles and diverse regulation. Yeast. 1996;12:1647-75 pubmed
    ..This review will summarize recent progress in understanding the structure, function and regulation of the PPP family of protein serine-threonine phosphatases, concentrating on the budding yeast Saccharomyces cerevisiae. ..
  2. Munoz I, Simon E, Casals N, Clotet J, Arino J. Identification of multicopy suppressors of cell cycle arrest at the G1-S transition in Saccharomyces cerevisiae. Yeast. 2003;20:157-69 pubmed
    Inactivation of HAL3 in the absence of SIT4 function leads to cell cycle arrest at the G(1)-S transition...
  3. Jablonowski D, Fichtner L, Stark M, Schaffrath R. The yeast elongator histone acetylase requires Sit4-dependent dephosphorylation for toxin-target capacity. Mol Biol Cell. 2004;15:1459-69 pubmed
    ..Tot1 dephosphorylation depends on the Sit4 phosphatase and its associators Sap185 and Sap190...
  4. Angeles de la Torre Ruiz M, Torres J, Arino J, Herrero E. Sit4 is required for proper modulation of the biological functions mediated by Pkc1 and the cell integrity pathway in Saccharomyces cerevisiae. J Biol Chem. 2002;277:33468-76 pubmed
    ..we report that correct down-regulation of both basal and induced activity of the PKC1-MAPK pathway requires the SIT4 function. Sit4 is a protein phosphatase also required for a proper cell cycle progression...
  5. Fernandez Sarabia M, Sutton A, Zhong T, Arndt K. SIT4 protein phosphatase is required for the normal accumulation of SWI4, CLN1, CLN2, and HCS26 RNAs during late G1. Genes Dev. 1992;6:2417-28 pubmed
    ..The SIT4 gene, which encodes a serine/threonine protein phosphatase, is required for the normal accumulation of CLN1, CLN2, ..
  6. Wang H, Wang X, Jiang Y. Interaction with Tap42 is required for the essential function of Sit4 and type 2A phosphatases. Mol Biol Cell. 2003;14:4342-51 pubmed
    In Saccharomyces cerevisiae, Pph21 and Pph22 are the two catalytic subunits of type 2A phosphatase (PP2Ac), and Sit4 is a major form of 2A-like phosphatase...
  7. Luke M, Della Seta F, Di Como C, Sugimoto H, Kobayashi R, Arndt K. The SAP, a new family of proteins, associate and function positively with the SIT4 phosphatase. Mol Cell Biol. 1996;16:2744-55 pubmed
    b>SIT4 is the catalytic subunit of a type 2A-related protein phosphatase in Saccharomyces cerevisiae that is required for G1 cyclin transcription and for bud formation...
  8. Huang B, Lu J, Byström A. A genome-wide screen identifies genes required for formation of the wobble nucleoside 5-methoxycarbonylmethyl-2-thiouridine in Saccharomyces cerevisiae. RNA. 2008;14:2183-94 pubmed publisher
    ..Analysis of the remaining mutants and other known gamma-toxin resistant mutants revealed that sit4, kti14, and KTI5 mutants also have a defect in the formation of mcm(5)...
  9. Van Hoof C, Martens E, Longin S, Jordens J, Stevens I, Janssens V, et al. Specific interactions of PP2A and PP2A-like phosphatases with the yeast PTPA homologues, Ypa1 and Ypa2. Biochem J. 2005;386:93-102 pubmed
    ..Ypa1 interacts specifically with Pph3, Sit4 and Ppg1, whereas Ypa2 binds to Pph21 and Pph22...
  10. Clotet J, Gari E, Aldea M, Arino J. The yeast ser/thr phosphatases sit4 and ppz1 play opposite roles in regulation of the cell cycle. Mol Cell Biol. 1999;19:2408-15 pubmed
    ..expression of HAL3/SIS2 has been reported to improve cell growth and to increase expression of G1 cyclins in sit4 phosphatase mutants...
  11. Nakashima A, Maruki Y, Imamura Y, Kondo C, Kawamata T, Kawanishi I, et al. The yeast Tor signaling pathway is involved in G2/M transition via polo-kinase. PLoS ONE. 2008;3:e2223 pubmed publisher
    ..The C-terminal polo-box domain of Cdc5 has an inhibitory role in nuclear translocation. Taken together, our results indicate a novel function of Tor in the regulation of cell cycle and proliferation. ..
  12. Kabir M, Kaminska J, Segel G, Bethlendy G, Lin P, Della Seta F, et al. Physiological effects of unassembled chaperonin Cct subunits in the yeast Saccharomyces cerevisiae. Yeast. 2005;22:219-39 pubmed
    ..Furthermore, we also suggest that the Cct subunits can act as suppressors only in certain states, such as when associated with ATP. ..
  13. Jouvet N, Poschmann J, Douville J, Bulet L, Ramotar D. Rrd1 isomerizes RNA polymerase II in response to rapamycin. BMC Mol Biol. 2010;11:92 pubmed publisher
    ..We propose as a mechanism, that upon rapamycin exposure Rrd1 isomerizes Rpb1 to promote its dissociation from the chromatin in order to modulate transcription. ..
  14. Souza A, Miranda M, da Silva S, Bozaquel Morais B, Masuda C, Ghislain M, et al. Expression of the glucose transporter HXT1 involves the Ser-Thr protein phosphatase Sit4 in Saccharomyces cerevisiae. FEMS Yeast Res. 2012;12:907-17 pubmed publisher
    We studied the effect of the loss of the Ser-Thr protein phosphatase Sit4, an important post-translational regulator, on the steady-state levels of the low-affinity glucose transporter Hxt1p and observed a delay in its appearance after ..
  15. Jin C, Barrientos A, Epstein C, Butow R, Tzagoloff A. SIT4 regulation of Mig1p-mediated catabolite repression in Saccharomyces cerevisiae. FEBS Lett. 2007;581:5658-63 pubmed
    ..Our evidence suggests that this pathway involves turnover of Mig1p. ..
  16. Hayashi N, Kobayashi M, Shimizu H, Yamamoto K, Murakami S, Nishimoto T. Mutations in Ran system affected telomere silencing in Saccharomyces cerevisiae. Biochem Biophys Res Commun. 2007;363:788-94 pubmed
    ..The reduced telomere silencing in rna1-1 cells was suppressed by a high dosage of the SIR3 gene or the SIT4 gene. Furthermore, hyperphosphorylated Sir3 protein accumulated in the rna1-1 mutant...
  17. Yan G, Shen X, Jiang Y. Rapamycin activates Tap42-associated phosphatases by abrogating their association with Tor complex 1. EMBO J. 2006;25:3546-55 pubmed
    ..In addition, our data support a model in which rapamycin acts not by inhibiting the kinase activity of Tor but by disrupting its interaction with downstream targets. ..
  18. Vilaça R, Barros I, Matmati N, Silva E, Martins T, Teixeira V, et al. The ceramide activated protein phosphatase Sit4 impairs sphingolipid dynamics, mitochondrial function and lifespan in a yeast model of Niemann-Pick type C1. Biochim Biophys Acta Mol Basis Dis. 2018;1864:79-88 pubmed publisher
    ..Moreover, the activation of Sit4, a ceramide-activated protein phosphatase, increased in ncr1? cells...
  19. Stettler S, Chiannilkulchai N, Hermann Le Denmat S, Lalo D, Lacroute F, Sentenac A, et al. A general suppressor of RNA polymerase I, II and III mutations in Saccharomyces cerevisiae. Mol Gen Genet. 1993;239:169-76 pubmed
    ..cerevisiae. SSD1-v was previously shown to suppress mutations defective in the SIT4 gene product (a predicted protein phosphatase subunit) or in the regulatory subunit of the cyclic AMP-dependent ..
  20. Nickels J, Broach J. A ceramide-activated protein phosphatase mediates ceramide-induced G1 arrest of Saccharomyces cerevisiae. Genes Dev. 1996;10:382-94 pubmed
    ..protein phosphatase composed of regulatory subunits encoded by TPD3 and CDC55 and a catalytic subunit encoded by SIT4. Because mutation of any one of these three genes renders strains resistant to ceramide inhibition, we conclude ..
  21. Morales Johansson H, Puria R, Brautigan D, Cardenas M. Human protein phosphatase PP6 regulatory subunits provide Sit4-dependent and rapamycin-sensitive sap function in Saccharomyces cerevisiae. PLoS ONE. 2009;4:e6331 pubmed publisher
    In the budding yeast Saccharomyces cerevisiae the protein phosphatase Sit4 and four associated proteins (Sap4, Sap155, Sap185, and Sap190) mediate G(1) to S cell cycle progression and a number of signaling events controlled by the target ..
  22. Jensen A, Chindaudomsate W, Thitiananpakorn K, Mongkolsuk S, Jensen L. Improper protein trafficking contributes to artemisinin sensitivity in cells lacking the KDAC Rpd3p. FEBS Lett. 2014;588:4018-25 pubmed publisher
    ..of RPD3, but not other KDAC genes, resulted in strong sensitivity to artemisinin, which was also observed in sit4Δ mutants with impaired endoplasmic reticulum (ER) to Golgi protein trafficking...
  23. Woodacre A, Lone M, Jablonowski D, Schneiter R, Giorgini F, Schaffrath R. A novel Sit4 phosphatase complex is involved in the response to ceramide stress in yeast. Oxid Med Cell Longev. 2013;2013:129645 pubmed publisher
    ..Ceramide activated protein phosphatase activity has been previously observed in association with the Sit4 protein phosphatase...
  24. Jacinto E, Guo B, Arndt K, Schmelzle T, Hall M. TIP41 interacts with TAP42 and negatively regulates the TOR signaling pathway. Mol Cell. 2001;8:1017-26 pubmed
    In Saccharomyces cerevisiae, the rapamycin-sensitive TOR kinases negatively regulate the type 2A-related phosphatase SIT4 by promoting the association of this phosphatase with the inhibitor TAP42...
  25. Tate J, Feller A, Dubois E, Cooper T. Saccharomyces cerevisiae Sit4 phosphatase is active irrespective of the nitrogen source provided, and Gln3 phosphorylation levels become nitrogen source-responsive in a sit4-deleted strain. J Biol Chem. 2006;281:37980-92 pubmed
    ..Tap42 then complexes with and inactivates Sit4 phosphatase, thereby preventing it from dephosphorylating Gln3...
  26. Simon E, Clotet J, Calero F, Ramos J, Arino J. A screening for high copy suppressors of the sit4 hal3 synthetically lethal phenotype reveals a role for the yeast Nha1 antiporter in cell cycle regulation. J Biol Chem. 2001;276:29740-7 pubmed
    A screening for multicopy suppressors of the G(1)/S blockage of a conditional sit4 hal3 mutant yielded the NHA1 gene, encoding a Na(+),K(+)/H(+) antiporter, composed of a transmembrane domain and a large carboxyl-terminal tail, which has ..
  27. Singer T, Haefner S, Hoffmann M, Fischer M, Ilyina J, Hilt W. Sit4 phosphatase is functionally linked to the ubiquitin-proteasome system. Genetics. 2003;164:1305-21 pubmed
    Using a synthetic lethality screen we found that the Sit4 phosphatase is functionally linked to the ubiquitin-proteasome system...
  28. Teixeira V, Medeiros T, Vilaça R, Ferreira J, Moradas Ferreira P, Costa V. Ceramide signaling targets the PP2A-like protein phosphatase Sit4p to impair vacuolar function, vesicular trafficking and autophagy in Isc1p deficient cells. Biochim Biophys Acta. 2016;1861:21-33 pubmed publisher
    ..These results support a model in which Sit4p functions downstream of Isc1p in a TORC1-independent, ceramide-dependent signaling branch that impairs vacuolar function and vesicular trafficking, leading to autophagic defects in yeast. ..
  29. Georis I, Tate J, Feller A, Cooper T, Dubois E. Intranuclear function for protein phosphatase 2A: Pph21 and Pph22 are required for rapamycin-induced GATA factor binding to the DAL5 promoter in yeast. Mol Cell Biol. 2011;31:92-104 pubmed publisher
    ..e., ure2? is epistatic to pph21? pph22?. This final observation adds additional support to our previous conclusion that the Gln3 and Gat1 GATA factor localizations are predominantly controlled by different regulatory pathways. ..
  30. Di Como C, Bose R, Arndt K. Overexpression of SIS2, which contains an extremely acidic region, increases the expression of SWI4, CLN1 and CLN2 in sit4 mutants. Genetics. 1995;139:95-107 pubmed
    ..identified by its ability, when present on a high copy number plasmid, to increase dramatically the growth rate of sit4 mutants...
  31. Kim Y, Francisco L, Chen G, Marcotte E, Chan C. Control of cellular morphogenesis by the Ip12/Bem2 GTPase-activating protein: possible role of protein phosphorylation. J Cell Biol. 1994;127:1381-94 pubmed
    ..also known as SRK1) mutation, which was shown previously to suppress mutations in the protein phosphatase-encoding SIT4 gene...
  32. Ruiz A, Munoz I, Serrano R, González A, Simon E, Arino J. Functional characterization of the Saccharomyces cerevisiae VHS3 gene: a regulatory subunit of the Ppz1 protein phosphatase with novel, phosphatase-unrelated functions. J Biol Chem. 2004;279:34421-30 pubmed
    ..YOR054c) has been recently identified as a multicopy suppressor of the G(1)/S cell cycle blockade of a conditional sit4 and hal3 mutant...
  33. Tate J, Georis I, Feller A, Dubois E, Cooper T. Rapamycin-induced Gln3 dephosphorylation is insufficient for nuclear localization: Sit4 and PP2A phosphatases are regulated and function differently. J Biol Chem. 2009;284:2522-34 pubmed publisher
    ..In Raptreated or Pro-grown cells, Sit4 is posited to dephosphorylate Gln3, which then dissociates from a Gln3-Ure2 complex and enters the nucleus...
  34. Rossio V, Michimoto T, Sasaki T, Ohbayashi I, Kikuchi Y, Yoshida S. Nuclear PP2A-Cdc55 prevents APC-Cdc20 activation during the spindle assembly checkpoint. J Cell Sci. 2013;126:4396-405 pubmed publisher
    ..Because the Cdc55-binding proteins Zds1 and Zds2 inhibit both nuclear accumulation of Cdc55 and SAC activity, we propose that spatial control of PP2A by Zds1 family proteins is important for tight control of SAC and mitotic progression. ..
  35. Luke M, Sutton A, Arndt K. Characterization of SIS1, a Saccharomyces cerevisiae homologue of bacterial dnaJ proteins. J Cell Biol. 1991;114:623-38 pubmed
    ..was identified as a high copy number suppressor of the slow growth phenotype of strains containing mutations in the SIT4 gene, which encodes a predicted serine/threonine protein phosphatase...
  36. Linderholm A, Findleton C, Kumar G, Hong Y, Bisson L. Identification of genes affecting hydrogen sulfide formation in Saccharomyces cerevisiae. Appl Environ Microbiol. 2008;74:1418-27 pubmed publisher
    ..In most cases, creation of multiple deletions of the 16 mutations in the same strain did not lead to a further increase in H(2)S production, instead often resulting in decreased levels. ..
  37. Bruckner S, Kern S, Birke R, Saugar I, Ulrich H, Mösch H. The TEA transcription factor Tec1 links TOR and MAPK pathways to coordinate yeast development. Genetics. 2011;189:479-94 pubmed publisher
    ..under control of the nutrient-sensitive target of rapamycin complex 1 (TORC1) signaling pathway via the Tip41-Tap42-Sit4 branch...
  38. López Mirabal H, Winther J, Kielland Brandt M. Oxidant resistance in a yeast mutant deficient in the Sit4 phosphatase. Curr Genet. 2008;53:275-86 pubmed publisher
    Resistance to thiol oxidation can arise from mutations altering redox homeostasis. A Saccharomyces cerevisiae sit4-110 mutant is here described, which was isolated as resistant to the thiol-specific oxidant dipyridyl disulfide (DPS) and ..
  39. Numamoto M, Sasano Y, Hirasaki M, Sugiyama M, Maekawa H, Harashima S. The protein phosphatase Siw14 controls caffeine-induced nuclear localization and phosphorylation of Gln3 via the type 2A protein phosphatases Pph21 and Pph22 in Saccharomyces cerevisiae. J Biochem. 2015;157:53-64 pubmed publisher induced by activation of the type 2A phosphatases (PP2As) Pph21 and Pph22, and the type 2A-related phosphatase Sit4. In this study, we show that the increased nuclear localization of Gln3 in response to caffeine caused by ..
  40. Garipler G, Mutlu N, Lack N, Dunn C. Deletion of conserved protein phosphatases reverses defects associated with mitochondrial DNA damage in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 2014;111:1473-8 pubmed publisher
    ..Our work highlights the important role that nutrient-responsive signaling pathways can play in determining the response to mitochondrial dysfunction. ..
  41. Abrie J, González A, Strauss E, Arino J. Functional mapping of the disparate activities of the yeast moonlighting protein Hal3. Biochem J. 2012;442:357-68 pubmed publisher
    ..Taken together, our work highlights specific structural determinants that could be exploited for full understanding of Hal3's cellular functions. ..
  42. Ruiz A, Xu X, Carlson M. Roles of two protein phosphatases, Reg1-Glc7 and Sit4, and glycogen synthesis in regulation of SNF1 protein kinase. Proc Natl Acad Sci U S A. 2011;108:6349-54 pubmed publisher
    ..We present evidence that Sit4, a type 2A-like protein phosphatase, contributes to dephosphorylation of Snf1 Thr210...
  43. Parkes V, Johnston L. SPO12 and SIT4 suppress mutations in DBF2, which encodes a cell cycle protein kinase that is periodically expressed. Nucleic Acids Res. 1992;20:5617-23 pubmed a human small nuclear riboprotein, while the remaining two are genes which have been identified previously, SIT4 and SPO12...
  44. Zacchi L, Gomez Raja J, Davis D. Mds3 regulates morphogenesis in Candida albicans through the TOR pathway. Mol Cell Biol. 2010;30:3695-710 pubmed publisher
    ..Rapamycin also rescued the transcriptional and morphological defects associated with the loss of Sit4, a TOR pathway effector, but not the loss of Rim101 or Ras1...
  45. Barbosa A, Pereira C, Osorio H, Moradas Ferreira P, Costa V. The ceramide-activated protein phosphatase Sit4p controls lifespan, mitochondrial function and cell cycle progression by regulating hexokinase 2 phosphorylation. Cell Cycle. 2016;15:1620-30 pubmed publisher
    ..In this study, we show that hexokinase 2 (Hxk2p) is hyperphosphorylated in sit4? mutants grown in glucose medium by a Snf1p-independent mechanism and Hxk2p-S15A mutation suppresses phenotypes ..
  46. Jiang Y. An essential role of Tap42-associated PP2A and 2A-like phosphatases in Ty1 transcriptional silencing of S. cerevisiae. Yeast. 2008;25:755-64 pubmed publisher
    ..Mutations affecting components of the Tap42-associated PP2A/2A-like phosphatases (Tap42, redundant Pph21/Pph22 and Sit4) eliminate Ty1 transcriptional silencing and epistasis experiments show that the phosphatases function downstream ..
  47. Boeckstaens M, Llinares E, Van Vooren P, Marini A. The TORC1 effector kinase Npr1 fine tunes the inherent activity of the Mep2 ammonium transport protein. Nat Commun. 2014;5:3101 pubmed publisher
  48. Georis I, Feller A, Tate J, Cooper T, Dubois E. Nitrogen catabolite repression-sensitive transcription as a readout of Tor pathway regulation: the genetic background, reporter gene and GATA factor assayed determine the outcomes. Genetics. 2009;181:861-74 pubmed publisher
    ..Gln3 requires Sit4 phosphatase for nuclear localization and NCR-sensitive transcription while Gat1 does not...
  49. Doseff A, Arndt K. LAS1 is an essential nuclear protein involved in cell morphogenesis and cell surface growth. Genetics. 1995;141:857-71 pubmed
    ..for SSD1-v for viability were isolated, yielding one new gene, LAS1, and three previously identified genes, SIT4, BCK1/SLK1, and SMP3...
  50. Bhandari D, Zhang J, Menon S, Lord C, Chen S, Helm J, et al. Sit4p/PP6 regulates ER-to-Golgi traffic by controlling the dephosphorylation of COPII coat subunits. Mol Biol Cell. 2013;24:2727-38 pubmed publisher
    ..Hyperphosphorylated coat subunits accumulate in the sit4? mutant in vivo. In vitro, Sit4p dephosphorylates COPII coat subunits...
  51. Teixeira V, Medeiros T, Vilaça R, Pereira A, Chaves S, Côrte Real M, et al. Ceramide signalling impinges on Sit4p and Hog1p to promote mitochondrial fission and mitophagy in Isc1p-deficient cells. Cell Signal. 2015;27:1840-9 pubmed publisher
  52. González A, Casado C, Arino J, Casamayor A. Ptc6 is required for proper rapamycin-induced down-regulation of the genes coding for ribosomal and rRNA processing proteins in S. cerevisiae. PLoS ONE. 2013;8:e64470 pubmed publisher
    ..These effects cannot be attributed to the regulation of the Sch9 kinase, but they could involve modulation of the binding of the Ifh1 co-activator to specific gene promoters. ..
  53. de Assis L, Zingali R, Masuda C, Rodrigues S, Montero Lomeli M. Pyruvate decarboxylase activity is regulated by the Ser/Thr protein phosphatase Sit4p in the yeast Saccharomyces cerevisiae. FEMS Yeast Res. 2013;13:518-28 pubmed publisher
    Deletion of SIT4 phosphatase decreased the pyruvate decarboxylase activity, which is essential for directing the glucose flux to ethanol production. Concomitantly, a reduction in the fermentative capacity was observed...
  54. Kuepfer L, Peter M, Sauer U, Stelling J. Ensemble modeling for analysis of cell signaling dynamics. Nat Biotechnol. 2007;25:1001-6 pubmed
    ..Beyond revising our picture of TOR signaling, we expect ensemble modeling to help elucidate other insufficiently characterized cellular circuits. ..
  55. Cherkasova V, Qiu H, Hinnebusch A. Snf1 promotes phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 by activating Gcn2 and inhibiting phosphatases Glc7 and Sit4. Mol Cell Biol. 2010;30:2862-73 pubmed publisher
    ..galactose, but this occurs by inhibition of protein phosphatase 1alpha (PP1alpha; Glc7) and the PP2A-like enzyme Sit4, rather than activation of Gcn2...
  56. Arndt K, Styles C, Fink G. A suppressor of a HIS4 transcriptional defect encodes a protein with homology to the catalytic subunit of protein phosphatases. Cell. 1989;56:527-37 pubmed
    ..The SIT4 protein is over 50% identical to the catalytic subunit of bovine type 2A protein phosphatase...
  57. Gurunathan S, Marash M, Weinberger A, Gerst J. t-SNARE phosphorylation regulates endocytosis in yeast. Mol Biol Cell. 2002;13:1594-607 pubmed
    ..of the phosphatase by treatment with C(2)-ceramide, VBM/ELO gene inactivation, or by the overexpression of SIT4 was sufficient to confer rescue...
  58. Ruiz A, Liu Y, Xu X, Carlson M. Heterotrimer-independent regulation of activation-loop phosphorylation of Snf1 protein kinase involves two protein phosphatases. Proc Natl Acad Sci U S A. 2012;109:8652-7 pubmed publisher
    ..We further show that the Reg1-Glc7 protein phosphatase 1 and Sit4 type 2A-like phosphatase are largely responsible for dephosphorylation of Thr-210 of Snf1(1-309)...
  59. Shirra M, Rogers S, Alexander D, Arndt K. The Snf1 protein kinase and Sit4 protein phosphatase have opposing functions in regulating TATA-binding protein association with the Saccharomyces cerevisiae INO1 promoter. Genetics. 2005;169:1957-72 pubmed
    ..Here, we present evidence that the Sit4 protein phosphatase negatively regulates INO1 transcription...
  60. Tate J, Georis I, Dubois E, Cooper T. Distinct phosphatase requirements and GATA factor responses to nitrogen catabolite repression and rapamycin treatment in Saccharomyces cerevisiae. J Biol Chem. 2010;285:17880-95 pubmed publisher
    In yeast, rapamycin (Rap)-inhibited TorC1, and the phosphatases it regulates (Sit4 and PP2A) are components of a conserved pathway regulating the response of eukaryotic cells to nutrient availability...
  61. Simon E, Barceló A, Arino J. Mutagenesis analysis of the yeast Nha1 Na+/H+ antiporter carboxy-terminal tail reveals residues required for function in cell cycle. FEBS Lett. 2003;545:239-45 pubmed high-copy expression of the NHA1 gene is able to rescue the blockage at the G(1)/S transition of cells lacking Sit4 protein phosphatase and Hal3 activities...
  62. Sutton A, Freiman R. The Cak1p protein kinase is required at G1/S and G2/M in the budding yeast cell cycle. Genetics. 1997;147:57-71 pubmed
    ..Here we describe the isolation of a mutant allele of CAK1 in a synthetic lethal screen with the Sit4 protein phosphatase...
  63. Workman J, Chen H, Laribee R. Saccharomyces cerevisiae TORC1 Controls Histone Acetylation by Signaling Through the Sit4/PP6 Phosphatase to Regulate Sirtuin Deacetylase Nuclear Accumulation. Genetics. 2016;203:1733-46 pubmed publisher
    ..the activity of the sirtuin deacetylases Hst3 and Hst4 TORC1 does so through suppression of the Tap42-regulated Sit4 (PP6) phosphatase complex, as sit4? rescues histone acetylation under TORC1-repressive conditions...
  64. Scheidt V, Jüdes A, Bär C, Klassen R, Schaffrath R. Loss of wobble uridine modification in tRNA anticodons interferes with TOR pathway signaling. Microb Cell. 2014;1:416-424 pubmed publisher
    ..In line with nuclear import of Gln3 being under control of TOR and dephosphorylation by the Sit4 phosphatase, we identify novel TOR-sensitive sit4 mutations that confer rapamycin resistance and importantly, ..
  65. Hayashi N, Nomura T, Sakumoto N, Mukai Y, Kaneko Y, Harashima S, et al. The SIT4 gene, which encodes protein phosphatase 2A, is required for telomere function in Saccharomyces cerevisiae. Curr Genet. 2005;47:359-67 pubmed
    ..Among these strains, short telomeres were found in the sit4 disruptant that lacks one form of protein phosphatase 2A (PP2A)...
  66. Georis I, Tate J, Cooper T, Dubois E. Tor pathway control of the nitrogen-responsive DAL5 gene bifurcates at the level of Gln3 and Gat1 regulation in Saccharomyces cerevisiae. J Biol Chem. 2008;283:8919-29 pubmed publisher
    ..Gln3-Myc(13) localization is highly dependent upon Ure2 and type 2A-related phosphatase, Sit4. Ure2 is required for Gln3 to be restricted to the cytoplasm of cells provided with good nitrogen sources, and Sit4 ..
  67. Barbosa A, Osorio H, Sims K, Almeida T, Alves M, Bielawski J, et al. Role for Sit4p-dependent mitochondrial dysfunction in mediating the shortened chronological lifespan and oxidative stress sensitivity of Isc1p-deficient cells. Mol Microbiol. 2011;81:515-27 pubmed publisher
    ..Consequently, deletion of the SIT4 gene, which encodes for the catalytic subunit of type 2A ceramide-activated protein phosphatase in yeast, abolished ..