scholarly journals The Dual-Specificity Protein Phosphatase Yvh1p Regulates Sporulation, Growth, and Glycogen Accumulation Independently of Catalytic Activity in Saccharomyces cerevisiae via the Cyclic AMP-Dependent Protein Kinase Cascade

2000 ◽  
Vol 182 (12) ◽  
pp. 3517-3528 ◽  
Author(s):  
Alexander E. Beeser ◽  
Terrance G. Cooper
Keyword(s):  
Amino Acids ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphatase ◽  
Dependent Protein Kinase ◽  
Phosphatase Domain ◽  
Glycogen Accumulation ◽  
Kinase Cascade ◽  
Dependent Protein ◽  
Protein Kinase Cascade

ABSTRACT Yvh1p, a dual-specific protein phosphatase induced specifically by nitrogen starvation, regulates cell growth as well as initiation and completion of sporulation. We demonstrate that yvh1disruption mutants are also unable to accumulate glycogen in stationary phase. A catalytically inactive variant of yvh1 (C117S) and a DNA fragment encoding only the Yvh1p C-terminal 159 amino acids (which completely lacks the phosphatase domain) complement all three phenotypes as well as the wild-type allele; no complementation occurs with a fragment encoding only the C-terminal 74 amino acids. These observations argue that phosphatase activity is not required for the Yvh1p functions we measured. Mutations which decrease endogenous cyclic AMP (cAMP) levels partially suppress the sporulation and glycogen accumulation defects. In addition, reporter gene expression supported by a DRR2 promoter fragment, containing two stress response elements known to respond to cAMP-protein kinase A, decreases in ayvh1 disruption mutant. Therefore, our results identify three cellular processes that both require Yvh1p and respond to alterations in cAMP, and they lead us to suggest that Yvh1p may be a participant in and/or a contributor to regulation of the cAMP-dependent protein kinase cascade. The fact that decreasing the levels of cAMP alleviates the need for Yvh1p function supports this suggestion.

The Saccharomyces cerevisiae SRK1 gene, a suppressor of bcy1 and ins1, may be involved in protein phosphatase function

1991 ◽  
Vol 11 (6) ◽  
pp. 3369-3373
Author(s):  
R B Wilson ◽  
A A Brenner ◽  
T B White ◽  
M J Engler ◽  
J P Gaughran ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphatase ◽  
Shuttle Vector ◽  
Temperature Sensitive ◽  
Protein Kinase Activity ◽  
Dependent Protein Kinase ◽  
Cycle Arrest ◽  
Dependent Protein

The Saccharomyces cerevisiae SRK1 gene, when expressed on a low-copy shuttle vector, partially suppresses the phenotype associated with elevated levels of cyclic AMP-dependent protein kinase activity and suppresses the temperature-sensitive cell cycle arrest of the ins1 mutant. SRK1 is located on chromosome IV, 3 centimorgans from gcn2. A mutant carrying a deletion mutation in srk1 is viable. SRK1 encodes a 140-kDa protein with homology to the dis3+ protein from Schizosaccharomyces pombe. The ability of SRK1 to alleviate partially the defects caused by high levels of cyclic AMP-dependent protein kinase and the similarity of its encoded protein to dis3+ suggest that SRK1 may have a role in protein phosphatase function.

scholarly journals Control of Cortical Axon Elongation by a GABA-Driven Ca2+/Calmodulin-Dependent Protein Kinase Cascade

2009 ◽  
Vol 29 (43) ◽  
pp. 13720-13729 ◽  
Author(s):  
N. Ageta-Ishihara ◽  
S. Takemoto-Kimura ◽  
M. Nonaka ◽  
A. Adachi-Morishima ◽  
K. Suzuki ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Dependent Protein Kinase ◽  
Axon Elongation ◽  
Kinase Cascade ◽  
Dependent Protein ◽  
Protein Kinase Cascade

scholarly journals Fructose-2,6-bisphosphatase and 6-phosphofructo-2-kinase are separable in yeast

1987 ◽  
Vol 246 (3) ◽  
pp. 755-759 ◽  
Author(s):  
M Kretschmer ◽  
W Schellenberger ◽  
A Otto ◽  
R Kessler ◽  
E Hofmann
Keyword(s):  
Alkaline Phosphatase ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Dependent Protein Kinase ◽  
Km Value ◽  
Phosphatase 2A ◽  
Dependent Protein

Fructose-2,6-bisphosphatase was purified from yeast and separated from 6-phosphofructo-2-kinase and alkaline phosphatase. The enzyme released Pi from the 2-position of fructose 2,6-bisphosphate and formed fructose 6-phosphate in stoichiometric amounts. The enzyme displays hyperbolic kinetics towards fructose 2,6-bisphosphate, with a Km value of 0.3 microM. It is strongly inhibited by fructose 6-phosphate. The inhibition is counteracted by L-glycerol 3-phosphate. Phosphorylation of the enzyme by cyclic-AMP-dependent protein kinase causes inactivation, which is reversible by the action of protein phosphatase 2A.

scholarly journals The Croonian Lecture 1998. Identification of a protein kinase cascade of major importance in insulin signal transduction

1999 ◽  
Vol 354 (1382) ◽  
pp. 485-495 ◽  
Author(s):  
Philip Cohen
Keyword(s):  
Protein Kinase ◽  
Glycogen Synthase ◽  
European Population ◽  
Glycogen Synthase Kinase 3 ◽  
Dependent Protein Kinase ◽  
Insulin Signal Transduction ◽  
Intracellular Proteins ◽  
Kinase Cascade ◽  
Dependent Protein ◽  
Protein Kinase Cascade

Diabetes affects 3% of the European population and 140 million people worldwide, and is largely a disease of insulin resistance in which the tissues fail to respond to this hormone. This emphasizes the importance of understanding how insulin signals to the cell's interior. We have recently dissected a protein kinase cascade that is triggered by the formation of the insulin ‘second messenger’ phosphatidylinositide (3,4,5) trisphosphate (PtdIns(3,4,5)P 3 ) and which appears to mediate many of the metabolic actions of this hormone. The first enzyme in the cascade is termed 3–phosphoinositide–dependent protein kinase–1 (PDK1), because it only activates protein kinase B (PKB), the next enzyme in the pathway, in the presence of PtdIns(3,4,5)P 3 . PKB then inactivates glycogen synthase kinase–3 (GSK3). PDK1, PKB and GSK3 regulate many physiological events by phosphorylating a variety of intracellular proteins. In addition, PKB plays an important role in mediating protection against apoptosis by survival factors, such as insulin–like growth factor–1.

Regulation of an epithelial chloride channel by direct phosphorylation and dephosphorylation

1992 ◽  
Vol 263 (1) ◽  
pp. C172-C175 ◽  
Author(s):  
A. L. Finn ◽  
M. L. Gaido ◽  
M. Dillard ◽  
D. L. Brautigan
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Lipid Bilayers ◽  
Okadaic Acid ◽  
Specific Antibody ◽  
Chloride Channel ◽  
Protein Phosphatase ◽  
Dependent Protein Kinase ◽  
Phosphatase 2A ◽  
Dependent Protein

A native chloride channel in Necturus gallbladder epithelial cells is opened by a theophylline-induced rise in cellular cyclic AMP and is closed by removal of theophylline or by addition of specific antibody; however, it does not close if okadaic acid, an inhibitor of protein phosphatases 1 and 2A, is added. The purified channel reconstituted into lipid bilayers closes upon the addition of protein phosphatase 2A and is reopened by the addition of Mg-ATP and the catalytic subunit of cyclic AMP-dependent protein kinase. These results indicate that the channel protein is purified in a phosphorylated state and that its functional characteristics are at least partly controlled by direct phosphorylation and dephosphorylation.

scholarly journals SOK2 may regulate cyclic AMP-dependent protein kinase-stimulated growth and pseudohyphal development by repressing transcription.

1995 ◽  
Vol 15 (12) ◽  
pp. 6854-6863 ◽  
Author(s):  
M P Ward ◽  
C J Gimeno ◽  
G R Fink ◽  
S Garrett
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Cell Cycle Progression ◽  
Signal Transduction Pathway ◽  
Growth Defect ◽  
Dependent Protein Kinase ◽  
Glycogen Accumulation ◽  
Expression Of Genes ◽  
Pathway Expression ◽  
Dependent Protein

Yeast cyclic AMP (cAMP)-dependent protein kinase (PKA) activity is essential for growth and cell cycle progression. Dependence on PKA function can be partially relieved by overexpression of a gene, SOK2, whose product has significant homology with several fungal transcription factors (StuA from Aspergillus nidulans and Phd1 from Saccharomyces cerevisiae) that are associated with cellular differentiation and development. Deletion of SOK2 is not lethal but exacerbates the growth defect of strains compromised for PKA activity. Alterations in Sok2 protein production also affect the expression of genes involved in several other PKA-regulated processes, including glycogen accumulation (GAC1) and heat shock resistance (SSA3). These results suggest SOK2 plays a general regulatory role in the PKA signal transduction pathway. Expression of the PKA catalytic subunit genes is unaltered by deletion or overexpression of SOK2. Because homozygous sok2/sok2 diploid strains form pseudohyphae at an accelerated rate, the Sok2 protein may inhibit the switch from unicellular to filamentous growth, a process that is dependent on cAMP. Thus, the product of SOK2 may act downstream of PKA to regulate the expression of genes important in growth and development.

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