Skip to main content
Molecular and Cellular Biology logoLink to Molecular and Cellular Biology
. 1996 Aug;16(8):4357–4365. doi: 10.1128/mcb.16.8.4357

Pho85p, a cyclin-dependent protein kinase, and the Snf1p protein kinase act antagonistically to control glycogen accumulation in Saccharomyces cerevisiae.

D Huang 1, I Farkas 1, P J Roach 1
PMCID: PMC231434  PMID: 8754836

Abstract

In Saccharomyces cerevisiae, nutrient levels control multiple cellular processes. Cells lacking the SNF1 gene cannot express glucose-repressible genes and do not accumulate the storage polysaccharide glycogen. The impaired glycogen synthesis is due to maintenance of glycogen synthase in a hyperphosphorylated, inactive state. In a screen for second site suppressors of the glycogen storage defect of snf1 cells, we identified a mutant gene that restored glycogen accumulation and which was allelic with PHO85, which encodes a member of the cyclin-dependent kinase family. In cells with disrupted PHO85 genes, we observed hyperaccumulation of glycogen, activation of glycogen synthase, and impaired glycogen synthase kinase activity. In snf1 cells, glycogen synthase kinase activity was elevated. Partial purification of glycogen synthase kinase activity from yeast extracts resulted in the separation of two fractions by phenyl-Sepharose chromatography, both of which phosphorylated and inactivated glycogen synthase. The activity of one of these, GPK2, was inhibited by olomoucine, which potently inhibits cyclin-dependent protein kinases, and contained an approximately 36-kDa species that reacted with antibodies to Pho85p. Analysis of Ser-to-Ala mutations at the three potential Gsy2p phosphorylation sites in pho85 cells implicated Ser-654 and/or Thr-667 in PHO85 control of glycogen synthase. We propose that Pho85p is a physiological glycogen synthase kinase, possibly acting downstream of Snf1p.

Full Text

The Full Text of this article is available as a PDF (441.4 KB).

Selected References

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

  1. Bajwa W., Meyhack B., Rudolph H., Schweingruber A. M., Hinnen A. Structural analysis of the two tandemly repeated acid phosphatase genes in yeast. Nucleic Acids Res. 1984 Oct 25;12(20):7721–7739. doi: 10.1093/nar/12.20.7721. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  3. Cannon J. F., Pringle J. R., Fiechter A., Khalil M. Characterization of glycogen-deficient glc mutants of Saccharomyces cerevisiae. Genetics. 1994 Feb;136(2):485–503. doi: 10.1093/genetics/136.2.485. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Carling D., Aguan K., Woods A., Verhoeven A. J., Beri R. K., Brennan C. H., Sidebottom C., Davison M. D., Scott J. Mammalian AMP-activated protein kinase is homologous to yeast and plant protein kinases involved in the regulation of carbon metabolism. J Biol Chem. 1994 Apr 15;269(15):11442–11448. [PubMed] [Google Scholar]
  5. Carlson M., Osmond B. C., Botstein D. Mutants of yeast defective in sucrose utilization. Genetics. 1981 May;98(1):25–40. doi: 10.1093/genetics/98.1.25. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Celenza J. L., Carlson M. Cloning and genetic mapping of SNF1, a gene required for expression of glucose-repressible genes in Saccharomyces cerevisiae. Mol Cell Biol. 1984 Jan;4(1):49–53. doi: 10.1128/mcb.4.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cheng C., Mu J., Farkas I., Huang D., Goebl M. G., Roach P. J. Requirement of the self-glucosylating initiator proteins Glg1p and Glg2p for glycogen accumulation in Saccharomyces cerevisiae. Mol Cell Biol. 1995 Dec;15(12):6632–6640. doi: 10.1128/mcb.15.12.6632. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Coche T., Prozzi D., Legrain M., Hilger F., Vandenhaute J. Nucleotide sequence of the PHO81 gene involved in the regulation of the repressible acid phosphatase gene in Saccharomyces cerevisiae. Nucleic Acids Res. 1990 Apr 25;18(8):2176–2176. doi: 10.1093/nar/18.8.2176. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Creasy C. L., Madden S. L., Bergman L. W. Molecular analysis of the PHO81 gene of Saccharomyces cerevisiae. Nucleic Acids Res. 1993 Apr 25;21(8):1975–1982. doi: 10.1093/nar/21.8.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Entian K. D. A defect in carbon catabolite repression associated with uncontrollable and excessive maltose uptake. Mol Gen Genet. 1980;179(1):169–175. doi: 10.1007/BF00268460. [DOI] [PubMed] [Google Scholar]
  11. Entian K. D., Zimmermann F. K. Glycolytic enzymes and intermediates in carbon catabolite repression mutants of Saccharomyces cerevisiae. Mol Gen Genet. 1980 Jan;177(2):345–350. doi: 10.1007/BF00267449. [DOI] [PubMed] [Google Scholar]
  12. Espinoza F. H., Ogas J., Herskowitz I., Morgan D. O. Cell cycle control by a complex of the cyclin HCS26 (PCL1) and the kinase PHO85. Science. 1994 Nov 25;266(5189):1388–1391. doi: 10.1126/science.7973730. [DOI] [PubMed] [Google Scholar]
  13. Farkas I., Hardy T. A., DePaoli-Roach A. A., Roach P. J. Isolation of the GSY1 gene encoding yeast glycogen synthase and evidence for the existence of a second gene. J Biol Chem. 1990 Dec 5;265(34):20879–20886. [PubMed] [Google Scholar]
  14. Farkas I., Hardy T. A., Goebl M. G., Roach P. J. Two glycogen synthase isoforms in Saccharomyces cerevisiae are coded by distinct genes that are differentially controlled. J Biol Chem. 1991 Aug 25;266(24):15602–15607. [PubMed] [Google Scholar]
  15. Feng Z. H., Wilson S. E., Peng Z. Y., Schlender K. K., Reimann E. M., Trumbly R. J. The yeast GLC7 gene required for glycogen accumulation encodes a type 1 protein phosphatase. J Biol Chem. 1991 Dec 15;266(35):23796–23801. [PubMed] [Google Scholar]
  16. Fiol C. J., Mahrenholz A. M., Wang Y., Roeske R. W., Roach P. J. Formation of protein kinase recognition sites by covalent modification of the substrate. Molecular mechanism for the synergistic action of casein kinase II and glycogen synthase kinase 3. J Biol Chem. 1987 Oct 15;262(29):14042–14048. [PubMed] [Google Scholar]
  17. Flotow H., Roach P. J. Role of acidic residues as substrate determinants for casein kinase I. J Biol Chem. 1991 Feb 25;266(6):3724–3727. [PubMed] [Google Scholar]
  18. François J. M., Thompson-Jaeger S., Skroch J., Zellenka U., Spevak W., Tatchell K. GAC1 may encode a regulatory subunit for protein phosphatase type 1 in Saccharomyces cerevisiae. EMBO J. 1992 Jan;11(1):87–96. doi: 10.1002/j.1460-2075.1992.tb05031.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Glab N., Labidi B., Qin L. X., Trehin C., Bergounioux C., Meijer L. Olomoucine, an inhibitor of the cdc2/cdk2 kinases activity, blocks plant cells at the G1 to S and G2 to M cell cycle transitions. FEBS Lett. 1994 Oct 17;353(2):207–211. doi: 10.1016/0014-5793(94)01035-8. [DOI] [PubMed] [Google Scholar]
  20. Goldstein A., Lampen J. O. Beta-D-fructofuranoside fructohydrolase from yeast. Methods Enzymol. 1975;42:504–511. doi: 10.1016/0076-6879(75)42159-0. [DOI] [PubMed] [Google Scholar]
  21. Hardy T. A., Huang D., Roach P. J. Interactions between cAMP-dependent and SNF1 protein kinases in the control of glycogen accumulation in Saccharomyces cerevisiae. J Biol Chem. 1994 Nov 11;269(45):27907–27913. [PubMed] [Google Scholar]
  22. Hardy T. A., Roach P. J. Control of yeast glycogen synthase-2 by COOH-terminal phosphorylation. J Biol Chem. 1993 Nov 15;268(32):23799–23805. [PubMed] [Google Scholar]
  23. Hardy T. A., Wu D., Roach P. J. Novel Saccharomyces cerevisiae gene, MRK1, encoding a putative protein kinase with similarity to mammalian glycogen synthase kinase-3 and Drosophila Zeste-White3/Shaggy. Biochem Biophys Res Commun. 1995 Mar 17;208(2):728–734. doi: 10.1006/bbrc.1995.1398. [DOI] [PubMed] [Google Scholar]
  24. Hirst K., Fisher F., McAndrew P. C., Goding C. R. The transcription factor, the Cdk, its cyclin and their regulator: directing the transcriptional response to a nutritional signal. EMBO J. 1994 Nov 15;13(22):5410–5420. doi: 10.1002/j.1460-2075.1994.tb06876.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Hisamoto N., Sugimoto K., Matsumoto K. The Glc7 type 1 protein phosphatase of Saccharomyces cerevisiae is required for cell cycle progression in G2/M. Mol Cell Biol. 1994 May;14(5):3158–3165. doi: 10.1128/mcb.14.5.3158. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Huang D., Chun K. T., Goebl M. G., Roach P. J. Genetic interactions between REG1/HEX2 and GLC7, the gene encoding the protein phosphatase type 1 catalytic subunit in Saccharomyces cerevisiae. Genetics. 1996 May;143(1):119–127. doi: 10.1093/genetics/143.1.119. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Ito H., Fukuda Y., Murata K., Kimura A. Transformation of intact yeast cells treated with alkali cations. J Bacteriol. 1983 Jan;153(1):163–168. doi: 10.1128/jb.153.1.163-168.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Kaffman A., Herskowitz I., Tjian R., O'Shea E. K. Phosphorylation of the transcription factor PHO4 by a cyclin-CDK complex, PHO80-PHO85. Science. 1994 Feb 25;263(5150):1153–1156. doi: 10.1126/science.8108735. [DOI] [PubMed] [Google Scholar]
  29. Kramer R. A., Andersen N. Isolation of yeast genes with mRNA levels controlled by phosphate concentration. Proc Natl Acad Sci U S A. 1980 Nov;77(11):6541–6545. doi: 10.1073/pnas.77.11.6541. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  31. Lemire J. M., Willcocks T., Halvorson H. O., Bostian K. A. Regulation of repressible acid phosphatase gene transcription in Saccharomyces cerevisiae. Mol Cell Biol. 1985 Aug;5(8):2131–2141. doi: 10.1128/mcb.5.8.2131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Lew J., Huang Q. Q., Qi Z., Winkfein R. J., Aebersold R., Hunt T., Wang J. H. A brain-specific activator of cyclin-dependent kinase 5. Nature. 1994 Sep 29;371(6496):423–426. doi: 10.1038/371423a0. [DOI] [PubMed] [Google Scholar]
  33. Lillie S. H., Pringle J. R. Reserve carbohydrate metabolism in Saccharomyces cerevisiae: responses to nutrient limitation. J Bacteriol. 1980 Sep;143(3):1384–1394. doi: 10.1128/jb.143.3.1384-1394.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Madden S. L., Creasy C. L., Srinivas V., Fawcett W., Bergman L. W. Structure and expression of the PHO80 gene of Saccharomyces cerevisiae. Nucleic Acids Res. 1988 Mar 25;16(6):2625–2637. doi: 10.1093/nar/16.6.2625. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Madden S. L., Johnson D. L., Bergman L. W. Molecular and expression analysis of the negative regulators involved in the transcriptional regulation of acid phosphatase production in Saccharomyces cerevisiae. Mol Cell Biol. 1990 Nov;10(11):5950–5957. doi: 10.1128/mcb.10.11.5950. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Matsumoto K., Toh-e A., Oshima Y. Isolation and characterization of dominant mutations resistant to carbon catabolite repression of galactokinase synthesis in Saccharomyces cerevisiae. Mol Cell Biol. 1981 Feb;1(2):83–93. doi: 10.1128/mcb.1.2.83. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Matsumoto K., Yoshimatsu T., Oshima Y. Recessive mutations conferring resistance to carbon catabolite repression of galactokinase synthesis in Saccharomyces cerevisiae. J Bacteriol. 1983 Mar;153(3):1405–1414. doi: 10.1128/jb.153.3.1405-1414.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Measday V., Moore L., Ogas J., Tyers M., Andrews B. The PCL2 (ORFD)-PHO85 cyclin-dependent kinase complex: a cell cycle regulator in yeast. Science. 1994 Nov 25;266(5189):1391–1395. doi: 10.1126/science.7973731. [DOI] [PubMed] [Google Scholar]
  39. Mitchelhill K. I., Stapleton D., Gao G., House C., Michell B., Katsis F., Witters L. A., Kemp B. E. Mammalian AMP-activated protein kinase shares structural and functional homology with the catalytic domain of yeast Snf1 protein kinase. J Biol Chem. 1994 Jan 28;269(4):2361–2364. [PubMed] [Google Scholar]
  40. Nehlin J. O., Carlberg M., Ronne H. Control of yeast GAL genes by MIG1 repressor: a transcriptional cascade in the glucose response. EMBO J. 1991 Nov;10(11):3373–3377. doi: 10.1002/j.1460-2075.1991.tb04901.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Ni H. T., LaPorte D. C. Response of a yeast glycogen synthase gene to stress. Mol Microbiol. 1995 Jun;16(6):1197–1205. doi: 10.1111/j.1365-2958.1995.tb02342.x. [DOI] [PubMed] [Google Scholar]
  42. Niederacher D., Entian K. D. Characterization of Hex2 protein, a negative regulatory element necessary for glucose repression in yeast. Eur J Biochem. 1991 Sep 1;200(2):311–319. doi: 10.1111/j.1432-1033.1991.tb16187.x. [DOI] [PubMed] [Google Scholar]
  43. O'Neill E. M., Kaffman A., Jolly E. R., O'Shea E. K. Regulation of PHO4 nuclear localization by the PHO80-PHO85 cyclin-CDK complex. Science. 1996 Jan 12;271(5246):209–212. doi: 10.1126/science.271.5246.209. [DOI] [PubMed] [Google Scholar]
  44. Pearson R. B., Kemp B. E. Protein kinase phosphorylation site sequences and consensus specificity motifs: tabulations. Methods Enzymol. 1991;200:62–81. doi: 10.1016/0076-6879(91)00127-i. [DOI] [PubMed] [Google Scholar]
  45. Peng Z. Y., Trumbly R. J., Reimann E. M. Purification and characterization of glycogen synthase from a glycogen-deficient strain of Saccharomyces cerevisiae. J Biol Chem. 1990 Aug 15;265(23):13871–13877. [PubMed] [Google Scholar]
  46. Puziss J. W., Hardy T. A., Johnson R. B., Roach P. J., Hieter P. MDS1, a dosage suppressor of an mck1 mutant, encodes a putative yeast homolog of glycogen synthase kinase 3. Mol Cell Biol. 1994 Jan;14(1):831–839. doi: 10.1128/mcb.14.1.831. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Ronne H. Glucose repression in fungi. Trends Genet. 1995 Jan;11(1):12–17. doi: 10.1016/s0168-9525(00)88980-5. [DOI] [PubMed] [Google Scholar]
  48. Rowen D. W., Meinke M., LaPorte D. C. GLC3 and GHA1 of Saccharomyces cerevisiae are allelic and encode the glycogen branching enzyme. Mol Cell Biol. 1992 Jan;12(1):22–29. doi: 10.1128/mcb.12.1.22. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Santos R. C., Waters N. C., Creasy C. L., Bergman L. W. Structure-function relationships of the yeast cyclin-dependent kinase Pho85. Mol Cell Biol. 1995 Oct;15(10):5482–5491. doi: 10.1128/mcb.15.10.5482. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Schneider K. R., Smith R. L., O'Shea E. K. Phosphate-regulated inactivation of the kinase PHO80-PHO85 by the CDK inhibitor PHO81. Science. 1994 Oct 7;266(5182):122–126. doi: 10.1126/science.7939631. [DOI] [PubMed] [Google Scholar]
  51. Sengstag C., Hinnen A. A 28-bp segment of the Saccharomyces cerevisiae PHO5 upstream activator sequence confers phosphate control to the CYC1-lacZ gene fusion. Gene. 1988 Jul 30;67(2):223–228. doi: 10.1016/0378-1119(88)90399-x. [DOI] [PubMed] [Google Scholar]
  52. Shah H. C., Carlson G. P. Alteration by phenobarbital and 3-methyl-cholanthrene of functional and structural changes in rat liver due to carbon tetrachloride inhalation. J Pharmacol Exp Ther. 1975 Apr;193(1):281–292. [PubMed] [Google Scholar]
  53. Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. Skurat A. V., Roach P. J. Multiple mechanisms for the phosphorylation of C-terminal regulatory sites in rabbit muscle glycogen synthase expressed in COS cells. Biochem J. 1996 Jan 1;313(Pt 1):45–50. doi: 10.1042/bj3130045. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Skurat A. V., Roach P. J. Phosphorylation of sites 3a and 3b (Ser640 and Ser644) in the control of rabbit muscle glycogen synthase. J Biol Chem. 1995 May 26;270(21):12491–12497. doi: 10.1074/jbc.270.21.12491. [DOI] [PubMed] [Google Scholar]
  56. Stuart J. S., Frederick D. L., Varner C. M., Tatchell K. The mutant type 1 protein phosphatase encoded by glc7-1 from Saccharomyces cerevisiae fails to interact productively with the GAC1-encoded regulatory subunit. Mol Cell Biol. 1994 Feb;14(2):896–905. doi: 10.1128/mcb.14.2.896. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. TORRIANI A. Influence of inorganic phosphate in the formation of phosphatases by Escherichia coli. Biochim Biophys Acta. 1960 Mar 11;38:460–469. doi: 10.1016/0006-3002(60)91281-6. [DOI] [PubMed] [Google Scholar]
  58. Tan A. W. A simplified method for the preparation of pure UDP[14C] glucose. Biochim Biophys Acta. 1979 Feb 1;582(3):543–547. doi: 10.1016/0304-4165(79)90146-6. [DOI] [PubMed] [Google Scholar]
  59. Thomas J. A., Schlender K. K., Larner J. A rapid filter paper assay for UDPglucose-glycogen glucosyltransferase, including an improved biosynthesis of UDP-14C-glucose. Anal Biochem. 1968 Oct 24;25(1):486–499. doi: 10.1016/0003-2697(68)90127-9. [DOI] [PubMed] [Google Scholar]
  60. Thompson-Jaeger S., François J., Gaughran J. P., Tatchell K. Deletion of SNF1 affects the nutrient response of yeast and resembles mutations which activate the adenylate cyclase pathway. Genetics. 1991 Nov;129(3):697–706. doi: 10.1093/genetics/129.3.697. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Thon V. J., Vigneron-Lesens C., Marianne-Pepin T., Montreuil J., Decq A., Rachez C., Ball S. G., Cannon J. F. Coordinate regulation of glycogen metabolism in the yeast Saccharomyces cerevisiae. Induction of glycogen branching enzyme. J Biol Chem. 1992 Jul 25;267(21):15224–15228. [PubMed] [Google Scholar]
  62. Timblin B. K., Tatchell K., Bergman L. W. Deletion of the gene encoding the cyclin-dependent protein kinase Pho85 alters glycogen metabolism in Saccharomyces cerevisiae. Genetics. 1996 May;143(1):57–66. doi: 10.1093/genetics/143.1.57. [DOI] [PMC free article] [PubMed] [Google Scholar]
  63. To-E A., Ueda Y., Kakimoto S. I., Oshima Y. Isolation and characterization of acid phosphatase mutants in Saccharomyces cerevisiae. J Bacteriol. 1973 Feb;113(2):727–738. doi: 10.1128/jb.113.2.727-738.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Toh-e A., Tanaka K., Uesono Y., Wickner R. B. PHO85, a negative regulator of the PHO system, is a homolog of the protein kinase gene, CDC28, of Saccharomyces cerevisiae. Mol Gen Genet. 1988 Sep;214(1):162–164. doi: 10.1007/BF00340196. [DOI] [PubMed] [Google Scholar]
  65. Tsai L. H., Delalle I., Caviness V. S., Jr, Chae T., Harlow E. p35 is a neural-specific regulatory subunit of cyclin-dependent kinase 5. Nature. 1994 Sep 29;371(6496):419–423. doi: 10.1038/371419a0. [DOI] [PubMed] [Google Scholar]
  66. Uesono Y., Tokai M., Tanaka K., Tohe A. Negative regulators of the PHO system of Saccharomyces cerevisiae: characterization of PHO80 and PHO85. Mol Gen Genet. 1992 Feb;231(3):426–432. doi: 10.1007/BF00292712. [DOI] [PubMed] [Google Scholar]
  67. Veselý J., Havlicek L., Strnad M., Blow J. J., Donella-Deana A., Pinna L., Letham D. S., Kato J., Detivaud L., Leclerc S. Inhibition of cyclin-dependent kinases by purine analogues. Eur J Biochem. 1994 Sep 1;224(2):771–786. doi: 10.1111/j.1432-1033.1994.00771.x. [DOI] [PubMed] [Google Scholar]
  68. Woods A., Munday M. R., Scott J., Yang X., Carlson M., Carling D. Yeast SNF1 is functionally related to mammalian AMP-activated protein kinase and regulates acetyl-CoA carboxylase in vivo. J Biol Chem. 1994 Jul 29;269(30):19509–19515. [PubMed] [Google Scholar]
  69. Zhang W. M., Browner M. F., Fletterick R. J., DePaoli-Roach A. A., Roach P. J. Primary structure of rabbit skeletal muscle glycogen synthase deduced from cDNA clones. FASEB J. 1989 Nov;3(13):2532–2536. doi: 10.1096/fasebj.3.13.2509275. [DOI] [PubMed] [Google Scholar]
  70. Zimmermann F. K., Scheel I. Mutants of Saccharomyces cerevisiae resistant to carbon catabolite repression. Mol Gen Genet. 1977 Jul 7;154(1):75–82. doi: 10.1007/BF00265579. [DOI] [PubMed] [Google Scholar]

Articles from Molecular and Cellular Biology are provided here courtesy of Taylor & Francis

RESOURCES