scholarly journals Regulation of cation transport in Saccharomyces cerevisiae by the salt tolerance gene HAL3.

1995 ◽  
Vol 15 (10) ◽  
pp. 5470-5481 ◽  
Author(s):  
A Ferrando ◽  
S J Kron ◽  
G Rios ◽  
G R Fink ◽  
R Serrano
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Cell Cycle Control ◽  
Ion Homeostasis ◽  
Salt Sensitivity ◽  
Yeast Saccharomyces Cerevisiae ◽  
Dynamic Regulation ◽  
Calcium Dependent ◽  
Regulatory Circuit ◽  
Salt Tolerance Gene

Dynamic regulation of ion transport is essential for homeostasis as cells confront changes in their environment. The gene HAL3 encodes a novel component of this regulatory circuit in the yeast Saccharomyces cerevisiae. Overexpression of HAL3 improves growth of wild-type cells exposed to toxic concentrations of sodium and lithium and suppresses the salt sensitivity conferred by mutation of the calcium-dependent protein phosphatase calcineurin. Null mutants of HAL3 display salt sensitivity. The sequence of HAL3 gives little clue to its function. However, alterations in intracellular cation concentrations associated with changes in HAL3 expression suggest that HAL3 activity may directly increase cytoplasmic K+ and decrease Na+ and Li+. Cation efflux in S. cerevisiae is mediated by the P-type ATPase encoded by the ENA1/PMR24 gene, a putative plasma membrane Na+ pump whose expression is salt induced. Acting in concert with calcineurin, HAL3 is necessary for full activation of ENA1 expression. This functional complementarity is also reflected in the participation of both proteins in recovery from alpha-factor-induced growth arrest. Recently, HAL3 was isolated as a gene (named SIS2) which when overexpressed partially relieves loss of transcription of G1 cyclins in mutants lacking the protein phosphatase Sit4p. Therefore, HAL3 influences cell cycle control and ion homeostasis, acting in parallel to the protein phosphatases Sit4p and calcineurin.

Regulation of glutamine-repressible gene products by the GLN3 function in Saccharomyces cerevisiae

1984 ◽  
Vol 4 (12) ◽  
pp. 2758-2766
Author(s):  
A P Mitchell ◽  
B Magasanik
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glutamine Synthetase ◽  
Glutamate Dehydrogenase ◽  
Opposite Effect ◽  
Nuclear Gene ◽  
Yeast Saccharomyces Cerevisiae ◽  
Two Dimensional Gel Electrophoresis ◽  
Regulatory Circuit ◽  
Glutamate Dehydrogenase Activity ◽  
Glutamine Limitation

Mutants of the yeast Saccharomyces cerevisiae have been isolated which fail to derepress glutamine synthetase upon glutamine limitation. The mutations define a single nuclear gene, GLN3, which is located on chromosome 5 near HOM3 and HIS1 and is unlinked to the structural gene for glutamine synthetase, GLN1. The three gln3 mutations are recessive, and one is amber suppressible, indicating that the GLN3 product is a positive regulator of glutamine synthetase expression. Four polypeptides, in addition to the glutamine synthetase subunit are synthesized at elevated rates when GLN3+ cultures are shifted from glutamine to glutamate media as determined by pulse-labeling and one- and two-dimensional gel electrophoresis. The response of all four proteins is blocked by gln3 mutations. In addition, the elevated NAD-dependent glutamate dehydrogenase activity normally found in glutamate-grown cells is not found in gln3 mutants. Glutamine limitation of gln1 structural mutants has the opposite effect, causing elevated levels of NAD-dependent glutamate dehydrogenase even in the presence of ammonia. We suggest that there is a regulatory circuit that responds to glutamine availability through the GLN3 product.

scholarly journals Interaction among Btn1p, Btn2p, and Ist2p Reveals Potential Interplay among the Vacuole, Amino Acid Levels, and Ion Homeostasis in the Yeast Saccharomyces cerevisiae

2005 ◽  
Vol 4 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Yoojin Kim ◽  
Subrata Chattopadhyay ◽  
Sarahjane Locke ◽  
David A. Pearce
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Membrane Protein ◽  
Optimal Transport ◽  
Ion Homeostasis ◽  
Coiled Coil ◽  
Batten Disease ◽  
Yeast Saccharomyces Cerevisiae ◽  
Arginine Transport ◽  
Amino Acid Levels

ABSTRACT Btn2p, a novel cytosolic coiled-coil protein in Saccharomyces cerevisiae, was previously shown to interact with and to be necessary for the correct localization of Rhb1p, a regulator of arginine uptake, and Yif1p, a Golgi protein. We now report the biochemical and physical interactions of Btn2p with Ist2p, a plasma membrane protein that is thought to have a function in salt tolerance. A deletion in Btn2p (btn2Δ strains) results in a failure to correctly localize Ist2p, and strains lacking Btn2p and Ist2p (btn2Δ ist2Δ strains) are unable to grow in the presence of 0.5 or 1.0 M NaCl. Btn2p was originally identified as being up-regulated in a btn1Δ strain, which lacks the vacuolar-lysosomal membrane protein, Btn1p, and serves as a model for Batten disease. This up-regulation of Btn2p was shown to contribute to the maintenance of a stable vacuolar pH in the btn1Δ strain. Btn1p was subsequently shown to be required for the optimal transport of arginine into the vacuole. Interestingly, btn1Δ ist2Δ strains are also unable to grow in the presence of 0.5 or 1.0 M NaCl, and ist2Δ suppresses the vacuolar arginine transport defect in btn1Δ strains. Although further investigation is required, we speculate that altered vacuolar arginine transport in btn1Δ strains represents a mechanism for maintaining or balancing cellular ion homeostasis. Btn2p interacts with at least three proteins that are seemingly involved in different biological functions in different subcellular locations. Due to these multiple interactions, we conclude that Btn2p may play a regulatory role across the cell in response to alterations in the intracellular environment that may be caused by changes in amino acid levels or pH, a disruption in protein trafficking, or imbalances in ion homeostasis resulting from either genetic or environmental manipulation.

scholarly journals Protein Phosphatase Type 1 Regulates Ion Homeostasis in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1423-1437 ◽  
Author(s):  
Tara Williams-Hart ◽  
Xiaolin Wu ◽  
Kelly Tatchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Protein Phosphatase ◽  
Essential Gene ◽  
Ion Homeostasis ◽  
Iodide Uptake ◽  
Recessive Mutations ◽  
Protein Phosphatase Type 1 ◽  
Protein Phosphatase Type

Abstract Protein phosphatase type 1 (PP1) is encoded by the essential gene GLC7 in Saccharomyces cerevisiae. glc7-109 (K259A, R260A) has a dominant, hyperglycogen defect and a recessive, ion and drug sensitivity. Surprisingly, the hyperglycogen phenotype is partially retained in null mutants of GAC1, GIP2, and PIG1, which encode potential glycogen-targeting subunits of Glc7. The R260A substitution in GLC7 is responsible for the dominant and recessive traits of glc7-109. Another mutation at this residue, glc7-R260P, confers only salt sensitivity, indicating that the glycogen and salt traits of glc7-109 are due to defects in distinct physiological pathways. The glc7-109 mutant is sensitive to cations, aminoglycosides, and alkaline pH and exhibits increased rates of l-leucine and 3,3′-dihexyloxacarbocyanine iodide uptake, but it is resistant to molar concentrations of sorbitol or KCl, indicating that it has normal osmoregulation. KCl suppresses the ion and drug sensitivities of the glc7-109 mutant. The CsCl sensitivity of this mutant is suppressed by recessive mutations in PMA1, which encodes the essential plasma membrane H+ATPase. Together, these results indicate that Glc7 regulates ion homeostasis by controlling ion transport and/or plasma membrane potential, a new role for Glc7 in budding yeast.

scholarly journals Multiple effects of protein phosphatase 2A on nutrient-induced signalling in the yeast Saccharomyces cerevisiae

2001 ◽  
Vol 40 (4) ◽  
pp. 1020-1026 ◽  
Author(s):  
Ewa Sugajska ◽  
Wojciech Swiatek ◽  
Piotr Zabrocki ◽  
Ilse Geyskens ◽  
Johan M. Thevelein ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Yeast Saccharomyces Cerevisiae ◽  
Phosphatase 2A

scholarly journals Regulation of glutamine-repressible gene products by the GLN3 function in Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (12) ◽  
pp. 2758-2766 ◽  
Author(s):  
A P Mitchell ◽  
B Magasanik
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glutamine Synthetase ◽  
Glutamate Dehydrogenase ◽  
Opposite Effect ◽  
Nuclear Gene ◽  
Yeast Saccharomyces Cerevisiae ◽  
Two Dimensional Gel Electrophoresis ◽  
Regulatory Circuit ◽  
Glutamate Dehydrogenase Activity ◽  
Glutamine Limitation

Mutants of the yeast Saccharomyces cerevisiae have been isolated which fail to derepress glutamine synthetase upon glutamine limitation. The mutations define a single nuclear gene, GLN3, which is located on chromosome 5 near HOM3 and HIS1 and is unlinked to the structural gene for glutamine synthetase, GLN1. The three gln3 mutations are recessive, and one is amber suppressible, indicating that the GLN3 product is a positive regulator of glutamine synthetase expression. Four polypeptides, in addition to the glutamine synthetase subunit are synthesized at elevated rates when GLN3+ cultures are shifted from glutamine to glutamate media as determined by pulse-labeling and one- and two-dimensional gel electrophoresis. The response of all four proteins is blocked by gln3 mutations. In addition, the elevated NAD-dependent glutamate dehydrogenase activity normally found in glutamate-grown cells is not found in gln3 mutants. Glutamine limitation of gln1 structural mutants has the opposite effect, causing elevated levels of NAD-dependent glutamate dehydrogenase even in the presence of ammonia. We suggest that there is a regulatory circuit that responds to glutamine availability through the GLN3 product.

scholarly journals Gis4, a New Component of the Ion Homeostasis System in the Yeast Saccharomyces cerevisiae

2006 ◽  
Vol 5 (10) ◽  
pp. 1611-1621 ◽  
Author(s):  
Tian Ye ◽  
Raúl García-Salcedo ◽  
José Ramos ◽  
Stefan Hohmann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Salt Tolerance ◽  
Cell Surface ◽  
Ion Homeostasis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Snf1 Kinase ◽  
C Terminus ◽  
Surface Localization ◽  
As Stress

ABSTRACT Gis4 is a new component of the system required for acquisition of salt tolerance in Saccharomyces cerevisiae. The gis4Δ mutant is sensitive to Na+ and Li+ ions but not to osmotic stress. Genetic evidence suggests that Gis4 mediates its function in salt tolerance, at least partly, together with the Snf1 protein kinase and in parallel with the calcineurin protein phosphatase. When exposed to salt stress, mutants lacking gis4Δ display a defect in maintaining low intracellular levels of Na+ and Li+ ions and exporting those ions from the cell. This defect is due to diminished expression of the ENA1 gene, which encodes the Na+ and Li+ export pump. The protein sequence of Gis4 is poorly conserved and does not reveal any hints to its molecular function. Gis4 is enriched at the cell surface, probably due to C-terminal farnesylation. The CAAX box at the C terminus is required for cell surface localization but does not seem to be strictly essential for the function of Gis4 in salt tolerance. Gis4 and Snf1 seem to share functions in the control of ion homeostasis and ENA1 expression but not in glucose derepression, the best known role of Snf1. Together with additional evidence that links Gis4 genetically and physically to Snf1, it appears that Gis4 may function in a pathway in which Snf1 plays a specific role in controlling ion homeostasis. Hence, it appears that the conserved Snf1 kinase plays roles in different pathways controlling nutrient as well as stress response.

Protein phosphatase 2A in Saccharomyces cerevisiae: effects on cell growth and bud morphogenesis

1991 ◽  
Vol 11 (10) ◽  
pp. 4876-4884
Author(s):  
H Ronne ◽  
M Carlberg ◽  
G Z Hu ◽  
J O Nehlin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Yeast Cells ◽  
Limited Growth ◽  
Yeast Saccharomyces Cerevisiae ◽  
The Third ◽  
Phosphatase 2A ◽  
High Level ◽  
Mammalian Protein

We have cloned three genes for protein phosphatases in the yeast Saccharomyces cerevisiae. Two of the genes, PPH21 and PPH22, encode highly similar proteins that are homologs of the mammalian protein phosphatase 2A (PP2A), while the third gene, PPH3, encodes a new PP2A-related protein. Disruptions of either PPH21 or PPH22 had no effects, but spores disrupted for both genes produced very small colonies with few surviving cells. We conclude that PP2A performs an important function in yeast cells. A disruption of the third gene, PPH3, did not in itself affect growth, but it completely prevented growth of spores disrupted for both PPH21 and PPH22. Thus, PPH3 provides some PP2A-complementing activity which allows for a limited growth of PP2A-deficient cells. Strains were constructed in which we could study the phenotypes caused by either excess PP2A or total PP2A depletion. We found that the level of PP2A activity has dramatic effects on cell shape. PP2A-depleted cells develop an abnormal pear-shaped morphology which is particularly pronounced in the growing bud. In contrast, overexpression of PP2A produces more elongated cells, and high-level overexpression causes a balloonlike phenotype with huge swollen cells filled by large vacuoles.

scholarly journals KONSTRUKSI MUTAN PROTEIN FOSFATASE ptc2D Saccharomyces cerevisiae DENGAN METODE PENGGANTIAN GEN TARGET DENGAN POLYMERASE CHAIN REACTION (PCR)

Molekul ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Hermansyah Hermansyah
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Pcr Amplification ◽  
Selective Medium ◽  
Wild Type ◽  
Chain Reaction ◽  
Gene Encoding ◽  
Yeast Saccharomyces Cerevisiae ◽  
Polymerase Chain ◽  
Encoding Protein

Yeast Saccharomyces cerevisiae is an excellent model to studi genes function of eukarotic cells such as study of gene encoding protein phosphatase PTC2. Novel phenotypic caused by mutated gene is an important step to study function of gene. In this study constructed mutant of PTC2 gene encoding protein phosphatase. Method that used in this construction was replacement of target gene (PTC2) with auxotroph marker Candida albicans HIS3 by Polymer Chain Reaction (PCR) or called by PCR-mediated disruption. Mutant colonies which grew in selective medium SC without histidine were confirmed by PCR amplification. By using 1% Agarose gel electrophoresis the result showed that size of ptc2D::CgHIS3 transformant was 3.52 kb while wild type strain was 2.9 kb, indicated thatptc2D::CgHIS3 has integrated on chromosome V replacing PTC2 wild type.

scholarly journals The Molecular Function of the Yeast Polo-like Kinase Cdc5 in Cdc14 Release during Early Anaphase

2009 ◽  
Vol 20 (16) ◽  
pp. 3671-3679 ◽  
Author(s):  
Fengshan Liang ◽  
Fengzhi Jin ◽  
Hong Liu ◽  
Yanchang Wang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Budding Yeast ◽  
Molecular Function ◽  
Cyclin Dependent Kinase ◽  
Yeast Saccharomyces Cerevisiae ◽  
Protein Levels ◽  
Early Anaphase ◽  
Show Evidence ◽  
Mitotic Cyclin

In the budding yeast Saccharomyces cerevisiae , Cdc14 is sequestered within the nucleolus before anaphase entry through its association with Net1/Cfi1, a nucleolar protein. Protein phosphatase PP2ACdc55 dephosphorylates Net1 and keeps it as a hypophosphorylated form before anaphase. Activation of the Cdc fourteen early anaphase release (FEAR) pathway after anaphase entry induces a brief Cdc14 release from the nucleolus. Some of the components in the FEAR pathway, including Esp1, Slk19, and Spo12, inactivate PP2ACdc55, allowing the phosphorylation of Net1 by mitotic cyclin-dependent kinase (Cdk) (Clb2-Cdk1). However, the function of another FEAR component, the Polo-like kinase Cdc5, remains elusive. Here, we show evidence indicating that Cdc5 promotes Cdc14 release primarily by stimulating the degradation of Swe1, the inhibitory kinase for mitotic Cdk. First, we found that deletion of SWE1 partially suppresses the FEAR defects in cdc5 mutants. In contrast, high levels of Swe1 impair FEAR activation. We also demonstrated that the accumulation of Swe1 in cdc5 mutants is responsible for the decreased Net1 phosphorylation. Therefore, we conclude that the down-regulation of Swe1 protein levels by Cdc5 promotes FEAR activation by relieving the inhibition on Clb2-Cdk1, the kinase for Net1 protein.

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