scholarly journals Assembly of the PtdIns 4-kinase Stt4 complex at the plasma membrane requires Ypp1 and Efr3

2008 ◽  
Vol 183 (6) ◽  
pp. 1061-1074 ◽  
Author(s):  
Dan Baird ◽  
Chris Stefan ◽  
Anjon Audhya ◽  
Sabine Weys ◽  
Scott D. Emr
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Membrane Protein ◽  
Essential Gene ◽  
Additional Component ◽  
Lipid Kinase ◽  
Phosphoinositide Kinase ◽  
Multiple Copies ◽  
The Stability ◽  
Phosphatidylinositol 4

The phosphoinositide phosphatidylinositol 4-phosphate (PtdIns4P) is an essential signaling lipid that regulates secretion and polarization of the actin cytoskeleton. In Saccharomyces cerevisiae, the PtdIns 4-kinase Stt4 catalyzes the synthesis of PtdIns4P at the plasma membrane (PM). In this paper, we identify and characterize two novel regulatory components of the Stt4 kinase complex, Ypp1 and Efr3. The essential gene YPP1 encodes a conserved protein that colocalizes with Stt4 at cortical punctate structures and regulates the stability of this lipid kinase. Accordingly, Ypp1 interacts with distinct regions on Stt4 that are necessary for the assembly and recruitment of multiple copies of the kinase into phosphoinositide kinase (PIK) patches. We identify the membrane protein Efr3 as an additional component of Stt4 PIK patches. Efr3 is essential for assembly of both Ypp1 and Stt4 at PIK patches. We conclude that Ypp1 and Efr3 are required for the formation and architecture of Stt4 PIK patches and ultimately PM-based PtdIns4P signaling.

scholarly journals Comparative Roles of the Cell Wall and Cell Membrane in Limiting Uptake of Xenobiotic Molecules by Saccharomyces cerevisiae

2003 ◽  
Vol 47 (6) ◽  
pp. 2012-2014 ◽  
Author(s):  
Mustapha Aouida ◽  
Omar Tounekti ◽  
Omrane Belhadj ◽  
Lluis M. Mir
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Protein

ABSTRACT Using reversible electropermeabilization of cells and spheroplasts, we show that the cell wall and plasma membrane partly account for bleomycin resistance by acting as two independent barriers. We also report on the presence of a membrane protein that may be responsible for bleomycin internalization and toxicity in Saccharomyces cerevisiae.

scholarly journals Cell surface recycling in yeast: mechanisms and machineries

2016 ◽  
Vol 44 (2) ◽  
pp. 474-478 ◽  
Author(s):  
Chris MacDonald ◽  
Robert C. Piper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Membrane Protein ◽  
Cell Surface ◽  
Mammalian Cells ◽  
Genetic System ◽  
Integral Membrane Protein ◽  
Protein Activity ◽  
Yeast Saccharomyces Cerevisiae ◽  
Central Process

Sorting internalized proteins and lipids back to the cell surface controls the supply of molecules throughout the cell and regulates integral membrane protein activity at the surface. One central process in mammalian cells is the transit of cargo from endosomes back to the plasma membrane (PM) directly, along a route that bypasses retrograde movement to the Golgi. Despite recognition of this pathway for decades we are only beginning to understand the machinery controlling this overall process. The budding yeast Saccharomyces cerevisiae, a stalwart genetic system, has been routinely used to identify fundamental proteins and their modes of action in conserved trafficking pathways. However, the study of cell surface recycling from endosomes in yeast is hampered by difficulties that obscure visualization of the pathway. Here we briefly discuss how recycling is likely a more prevalent process in yeast than is widely appreciated and how tools might be built to better study the pathway.

scholarly journals Molecular analysis of GPH1, the gene encoding glycogen phosphorylase in Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (4) ◽  
pp. 1659-1666 ◽  
Author(s):  
P K Hwang ◽  
S Tugendreich ◽  
R J Fletterick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Phosphorylase ◽  
Glucose Repression ◽  
Essential Gene ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Phosphorylase Activity ◽  
Glycogen Accumulation ◽  
Multiple Copies ◽  
Diploid Cells

In yeast cells, the activity of glycogen phosphorylase is regulated by cyclic AMP-mediated phosphorylation of the enzyme. We have previously cloned the gene for glycogen phosphorylase (GPH1) in Saccharomyces cerevisiae. To assess the role of glycogen and phosphorylase-catalyzed glycogenolysis in the yeast life cycle, yeast strains lacking a functional GPH1 gene or containing multiple copies of the gene were constructed. GPH1 was found not to be an essential gene in yeast cells. Haploid cells disrupted in GPH1 lacked phosphorylase activity and attained higher levels of intracellular glycogen but otherwise were similar to wild-type cells. Diploid cells homozygous for the disruption were able to sporulate and give rise to viable ascospores. Absence of functional GPH1 did not impair cells from synthesizing and storing trehalose. Increases in phosphorylase activity of 10- to 40-fold were detected in cells carrying multiple copies of GPH1-containing 2 microns plasmid. Northern (RNA) analysis indicated that GPH1 transcription was induced at the late exponential growth phase, almost simultaneous with the onset of intracellular glycogen accumulation. Thus, the low level of glycogen in exponential cells was not primarily maintained through regulating the phosphorylation state of a constitutive amount of phosphorylase. GPH1 did not appear to be under formal glucose repression, since transcriptional induction occurred well in advance of glucose depletion from the medium.

Molecular analysis of GPH1, the gene encoding glycogen phosphorylase in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (4) ◽  
pp. 1659-1666 ◽  
Author(s):  
P K Hwang ◽  
S Tugendreich ◽  
R J Fletterick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Phosphorylase ◽  
Glucose Repression ◽  
Essential Gene ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Phosphorylase Activity ◽  
Glycogen Accumulation ◽  
Multiple Copies ◽  
Diploid Cells

In yeast cells, the activity of glycogen phosphorylase is regulated by cyclic AMP-mediated phosphorylation of the enzyme. We have previously cloned the gene for glycogen phosphorylase (GPH1) in Saccharomyces cerevisiae. To assess the role of glycogen and phosphorylase-catalyzed glycogenolysis in the yeast life cycle, yeast strains lacking a functional GPH1 gene or containing multiple copies of the gene were constructed. GPH1 was found not to be an essential gene in yeast cells. Haploid cells disrupted in GPH1 lacked phosphorylase activity and attained higher levels of intracellular glycogen but otherwise were similar to wild-type cells. Diploid cells homozygous for the disruption were able to sporulate and give rise to viable ascospores. Absence of functional GPH1 did not impair cells from synthesizing and storing trehalose. Increases in phosphorylase activity of 10- to 40-fold were detected in cells carrying multiple copies of GPH1-containing 2 microns plasmid. Northern (RNA) analysis indicated that GPH1 transcription was induced at the late exponential growth phase, almost simultaneous with the onset of intracellular glycogen accumulation. Thus, the low level of glycogen in exponential cells was not primarily maintained through regulating the phosphorylation state of a constitutive amount of phosphorylase. GPH1 did not appear to be under formal glucose repression, since transcriptional induction occurred well in advance of glucose depletion from the medium.

scholarly journals Differential regulation by phosphatidylinositol 4,5-bisphosphate of pituitary plasma-membrane and cytosolic phosphoinositide kinases

1986 ◽  
Vol 240 (2) ◽  
pp. 341-348 ◽  
Author(s):  
A Imai ◽  
M J Rebecchi ◽  
M C Gershengorn
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Product Inhibition ◽  
Differential Regulation ◽  
Gh3 Cells ◽  
Maximal Effect ◽  
Phosphatidylinositol Kinase ◽  
Rat Pituitary ◽  
Phosphoinositide Kinase ◽  
Phosphatidylinositol 4

Regulation of phosphatidylinositol kinase (EC 2.7.1.67) and phosphatidylinositol 4-phosphate (PtdIns4P) kinase (EC 2.7.1.68) was investigated in highly enriched plasma-membrane and cytosolic fractions derived from cloned rat pituitary (GH3) cells. In plasma membranes, phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] added exogenously enhanced incorporation of [32P]phosphate from [gamma-32P]MgATP2- into PtdIns(4,5)P2 and PtdIns4P to 150% of control; half-maximal effect occurred with 0.03 mM exogenous PtdIns(4,5)P2. Exogenous PtdIns4P and phosphatidylinositol (PtdIns) had no effect. When plasma membranes prepared from cells prelabelled to isotopic steady state with [3H]inositol were used, there was a MgATP2- dependent increase in the content of [3H]PtdIns(4,5)P2 and [3H]PtdIns4P that was enhanced specifically by exogenous PtdIns(4,5)P2 also. Degradation of 32P- and 3H-labelled PtdIns(4,5)P2 and PtdIns4P within the plasma-membrane fraction was not affected by exogenous PtdIns(4,5)P2. Phosphoinositide kinase activities in the cytosolic fraction were assayed by using exogenous substrates. Phosphoinositide kinase activities in cytosol were inhibited by exogenously added PtdIns(4,5)P2. These findings demonstrate that exogenously added PtdIns(4,5)P2 enhances phosphoinositide kinase activities (and formation of polyphosphoinositides) in plasma membranes, but decreases these kinase activities in cytosol derived from GH3 cells. These data suggest that flux of PtdIns to PtdIns4P to PtdIns(4,5)P2 in the plasma membrane cannot be increased simply by release of membrane-associated phosphoinositide kinases from product inhibition as PtdIns(4,5)P2 is hydrolysed.

scholarly journals TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (7) ◽  
pp. 2848-2859 ◽  
Author(s):  
R F Gaber ◽  
C A Styles ◽  
G R Fink
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Membrane Protein ◽  
Functional Independence ◽  
Potassium Transport ◽  
Transport Systems ◽  
Plasma Membrane Protein ◽  
Plasma Membrane Atpase ◽  
High Affinity ◽  
Membrane Spanning

We identified a 180-kilodalton plasma membrane protein in Saccharomyces cerevisiae required for high-affinity transport (uptake) of potassium. The gene that encodes this putative potassium transporter (TRK1) was cloned by its ability to relieve the potassium transport defect in trk1 cells. TRK1 encodes a protein 1,235 amino acids long that contains 12 potential membrane-spanning domains. Our results demonstrate the physical and functional independence of the yeast potassium and proton transport systems. TRK1 is nonessential in S. cerevisiae and maps to a locus unlinked to PMA1, the gene that encodes the plasma membrane ATPase. Haploid cells that contain a null allele of TRK1 (trk1 delta) rely on a low-affinity transporter for potassium uptake and, under certain conditions, exhibit energy-dependent loss of potassium, directly exposing the activity of a transporter responsible for the efflux of this ion.

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 Type II Phosphatidylinositol 4-Kinase β Is a Cytosolic and Peripheral Membrane Protein That Is Recruited to the Plasma Membrane and Activated by Rac-GTP

2002 ◽  
Vol 277 (48) ◽  
pp. 46586-46593 ◽  
Author(s):  
Yong Jie Wei ◽  
Hui Qiao Sun ◽  
Masaya Yamamoto ◽  
Pawel Wlodarski ◽  
Kaiko Kunii ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Protein ◽  
Type Ii ◽  
Peripheral Membrane Protein ◽  
Phosphatidylinositol 4

scholarly journals Phosphatidylinositol 4,5-bisphosphate is regenerated by speeding of the PI 4-kinase pathway during long PLC activation

2020 ◽  
Vol 152 (12) ◽  
Author(s):  
Jongyun Myeong ◽  
Lizbeth de la Cruz ◽  
Seung-Ryoung Jung ◽  
Jun-Hee Yeon ◽  
Byung-Chang Suh ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Lipid Kinase ◽  
Agonist Action ◽  
Lipid Species ◽  
Phosphoinositide Cycle ◽  
M1 Muscarinic ◽  
Phosphatidylinositol 4 ◽  
Cellular Compartments ◽  
Regulatory Controls

The dynamic metabolism of membrane phosphoinositide lipids involves several cellular compartments including the ER, Golgi, and plasma membrane. There are cycles of phosphorylation and dephosphorylation and of synthesis, transfer, and breakdown. The simplified phosphoinositide cycle comprises synthesis of phosphatidylinositol in the ER, transport, and phosphorylation in the Golgi and plasma membranes to generate phosphatidylinositol 4,5-bisphosphate, followed by receptor-stimulated hydrolysis in the plasma membrane and return of the components to the ER for reassembly. Using probes for specific lipid species, we have followed and analyzed the kinetics of several of these events during stimulation of M1 muscarinic receptors coupled to the G-protein Gq. We show that during long continued agonist action, polyphosphorylated inositol lipids are initially depleted but then regenerate while agonist is still present. Experiments and kinetic modeling reveal that the regeneration results from gradual but massive up-regulation of PI 4-kinase pathways rather than from desensitization of receptors. Golgi pools of phosphatidylinositol 4-phosphate and the lipid kinase PI4KIIIα (PI4KA) contribute to this homeostatic regeneration. This powerful acceleration, which may be at the level of enzyme activity or of precursor and product delivery, reveals strong regulatory controls in the phosphoinositide cycle.

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