Genetics, Vol 140, 457-467, Copyright © 1995

INVESTIGATIONS

sck1, a High Copy Number Suppressor of Defects in the cAMP-Dependent Protein Kinase Pathway in Fission Yeast, Encodes a Protein Homologous to the Saccharomyces cerevisiae SCH9 Kinase

M. Jin, M. Fujita, B. M. Culley, E. Apolinario, M. Yamamoto, K. Maundrell and C. S. Hoffman
Department of Biology, Boston College, Chestnut Hill, Massachusetts 02167 Present address: Research Institute, Miami Children's Hospital, Miami, FL 33155.

Schizosaccharomyces pombe regulates intracellular cAMP levels, and thus cAMP-dependent protein kinase (PKA) activity, in response to changes in nutrient conditions. Mutations in any of eight git genes inhibit glucose repression of fbp1 transcription, alter the cell morphology, and cause a reduction in the growth rate. The eight git genes encode components of an adenylate cyclase activation pathway, adenylate cyclase itself, and the catalytic subunit of PKA. Three of these genes have been identified in other studies as regulators of meiosis. Here we show that the sck1 gene, cloned as a high copy number suppressor of a mutation in git3, is able to suppress the defects conferred by a mutation in any of these git genes. Sequence analysis suggests that sck1 encodes a protein most closely related to the Saccharomyces cerevisiae SCH9 protein kinase that had previously been identified as a high copy number suppressor of mutations in S. cerevisiae that reduce or eliminate PKA activity. Disruption of the sck1 gene causes a significant delay in exit from stationary phase when combined with a disruption of the pka1 (git6) gene encoding the catalytic subunit of PKA. However, the sck1 disruption by itself has little or no effect upon fbp1 transcription, meiosis, or exit from stationary phase, and does not enhance the constitutive fbp1 transcription observed in a pka1 mutant. Therefore, sck1 appears to function in a redundant fashion to pka1, but to varying degrees, in the pathways regulated by pka1.

This article has been cited by other articles:

				M. A. Alaamery and C. S. Hoffman Schizosaccharomyces pombe Hsp90/Git10 Is Required for Glucose/cAMP Signaling Genetics, April 1, 2008; 178(4): 1927 - 1936. [Abstract] [Full Text] [PDF]

				K. Hirota, C. S. Hoffman, and K. Ohta Reciprocal Nuclear Shuttling of Two Antagonizing Zn Finger Proteins Modulates Tup Family Corepressor Function To Repress Chromatin Remodeling Eukaryot. Cell, December 1, 2006; 5(12): 1980 - 1989. [Abstract] [Full Text] [PDF]

				A. Sobko Systems Biology of AGC Kinases in Fungi Sci. Signal., September 12, 2006; 2006(352): re9 - re9. [Abstract] [Full Text] [PDF]

				R. S. Kao, E. Morreale, L. Wang, F. D. Ivey, and C. S. Hoffman Schizosaccharomyces pombe Git1 Is a C2-Domain Protein Required for Glucose Activation of Adenylate Cyclase Genetics, May 1, 2006; 173(1): 49 - 61. [Abstract] [Full Text] [PDF]

				L. Wang, K. Griffiths Jr., Y. H. Zhang, F. D. Ivey, and C. S. Hoffman Schizosaccharomyces pombe Adenylate Cyclase Suppressor Mutations Suggest a Role for cAMP Phosphodiesterase Regulation in Feedback Control of Glucose/cAMP Signaling Genetics, December 1, 2005; 171(4): 1523 - 1533. [Abstract] [Full Text] [PDF]

				A. Bimbo, Y. Jia, S. L. Poh, R. K. M. Karuturi, N. den Elzen, X. Peng, L. Zheng, M. O'Connell, E. T. Liu, M. K. Balasubramanian, et al. Systematic Deletion Analysis of Fission Yeast Protein Kinases Eukaryot. Cell, April 1, 2005; 4(4): 799 - 813. [Abstract] [Full Text] [PDF]

				Y. Tang and M. McLeod In Vivo Activation of Protein Kinase A in Schizosaccharomyces pombe Requires Threonine Phosphorylation at Its Activation Loop and Is Dependent on PDK1 Genetics, December 1, 2004; 168(4): 1843 - 1853. [Abstract] [Full Text] [PDF]

				K. Hirota, C. S. Hoffman, T. Shibata, and K. Ohta Fission Yeast Tup1-Like Repressors Repress Chromatin Remodeling at the fbp1+ Promoter and the ade6-M26 Recombination Hotspot Genetics, October 1, 2003; 165(2): 505 - 515. [Abstract] [Full Text] [PDF]

				N. Reynolds and H. Ohkura Polo boxes form a single functional domain that mediates interactions with multiple proteins in fission yeast polo kinase J. Cell Sci., April 1, 2003; 116(7): 1377 - 1387. [Abstract] [Full Text] [PDF]

				K. Schadick, H. M. Fourcade, P. Boumenot, J. J. Seitz, J. L. Morrell, L. Chang, K. L. Gould, J. F. Partridge, R. C. Allshire, K. Kitagawa, et al. Schizosaccharomyces pombe Git7p, a Member of the Saccharomyces cerevisiae Sgt1p Family, Is Required for Glucose and Cyclic AMP Signaling, Cell Wall Integrity, and Septation Eukaryot. Cell, August 1, 2002; 1(4): 558 - 567. [Abstract] [Full Text] [PDF]

				S. Landry and C. S. Hoffman The git5 G{beta} and git11 G{{gamma}} Form an Atypical G{beta}{{gamma}} Dimer Acting in the Fission Yeast Glucose/cAMP Pathway Genetics, March 1, 2001; 157(3): 1159 - 1168. [Abstract] [Full Text]

				R. T. K. Janoo, L. A. Neely, B. R. Braun, S. K. Whitehall, and C. S. Hoffman Transcriptional Regulators of the Schizosaccharomyces pombe fbp1 Gene Include Two Redundant Tup1p-like Corepressors and the CCAAT Binding Factor Activation Complex Genetics, March 1, 2001; 157(3): 1205 - 1215. [Abstract] [Full Text]

				A. Franco, T. Soto, J. Vicente-Soler, P. V. Guillen, J. Cansado, and M. Gacto Characterization of tpp1+ as Encoding a Main Trehalose-6P Phosphatase in the Fission Yeast Schizosaccharomyces pombe J. Bacteriol., October 15, 2000; 182(20): 5880 - 5884. [Abstract] [Full Text]

				R. M. Welton and C. S. Hoffman Glucose Monitoring in Fission Yeast via the gpa2 G{alpha}, the git5 G{beta} and the git3 Putative Glucose Receptor Genetics, October 1, 2000; 156(2): 513 - 521. [Abstract] [Full Text]

				L. A. Neely and C. S. Hoffman Protein Kinase A and Mitogen-Activated Protein Kinase Pathways Antagonistically Regulate Fission Yeast fbp1 Transcription by Employing Different Modes of Action at Two Upstream Activation Sites Mol. Cell. Biol., September 1, 2000; 20(17): 6426 - 6434. [Abstract] [Full Text]

				S. Landry, M. T. Pettit, E. Apolinario, and C. S. Hoffman The Fission Yeast git5 Gene Encodes a G{beta} Subunit Required for Glucose-Triggered Adenylate Cyclase Activation Genetics, April 1, 2000; 154(4): 1463 - 1471. [Abstract] [Full Text]

				W. A. Whalen, J. H. Yoon, R. Shen, and R. Dhar Regulation of mRNA Export by Nutritional Status in Fission Yeast Genetics, July 1, 1999; 152(3): 827 - 838. [Abstract] [Full Text]

				K. Adachi and J. E. Hamer Divergent cAMP Signaling Pathways Regulate Growth and Pathogenesis in the Rice Blast Fungus Magnaporthe grisea PLANT CELL, August 1, 1998; 10(8): 1361 - 1374. [Abstract] [Full Text]

				N. Okazaki, K. Okazaki, Y. Watanabe, M. Kato-Hayashi, M. Yamamoto, and H. Okayama Novel Factor Highly Conserved among Eukaryotes Controls Sexual Development in Fission Yeast Mol. Cell. Biol., February 1, 1998; 18(2): 887 - 895. [Abstract] [Full Text]

				P Dal Santo, B Blanchard, and C. Hoffman The Schizosaccharomyces pombe pyp1 protein tyrosine phosphatase negatively regulates nutrient monitoring pathways J. Cell Sci., January 7, 1996; 109(7): 1919 - 1925. [Abstract] [PDF]

				S Stettler, E Warbrick, S Prochnik, S Mackie, and P Fantes The wis1 signal transduction pathway is required for expression of cAMP-repressed genes in fission yeast J. Cell Sci., January 7, 1996; 109(7): 1927 - 1935. [Abstract] [PDF]