Faculty Opinions recommendation of Vacuolar and plasma membrane proton pumps collaborate to achieve cytosolic pH homeostasis in yeast.

2012 ◽  
Author(s):  
Christopher Loewen
Keyword(s):  
Plasma Membrane ◽  
Proton Pumps ◽  
Ph Homeostasis ◽  
Cytosolic Ph

scholarly journals Plant Proton Pumps and Cytosolic pH-Homeostasis

2021 ◽  
Vol 12 ◽  
Author(s):  
Maike Cosse ◽  
Thorsten Seidel
Keyword(s):  
Plasma Membrane ◽  
Secretory Pathway ◽  
Coordination Mechanisms ◽  
Proton Pumps ◽  
Plasma Membrane Atpase ◽  
Ph Homeostasis ◽  
Secondary Active Transport ◽  
Cytosolic Ph ◽  
Ion Concentrations ◽  
Membrane Atpase

Proton pumps create a proton motif force and thus, energize secondary active transport at the plasma nmembrane and endomembranes of the secretory pathway. In the plant cell, the dominant proton pumps are the plasma membrane ATPase, the vacuolar pyrophosphatase (V-PPase), and the vacuolar-type ATPase (V-ATPase). All these pumps act on the cytosolic pH by pumping protons into the lumen of compartments or into the apoplast. To maintain the typical pH and thus, the functionality of the cytosol, the activity of the pumps needs to be coordinated and adjusted to the actual needs. The cellular toolbox for a coordinated regulation comprises 14-3-3 proteins, phosphorylation events, ion concentrations, and redox-conditions. This review combines the knowledge on regulation of the different proton pumps and highlights possible coordination mechanisms.

scholarly journals pH-dependent Cargo Sorting from the Golgi

2011 ◽  
Vol 286 (12) ◽  
pp. 10058-10065 ◽  
Author(s):  
Chunjuan Huang ◽  
Amy Chang
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Atpase Activity ◽  
Secretory Pathway ◽  
Ph Dependence ◽  
Glucose Deprivation ◽  
Ph Homeostasis ◽  
Plasma Membrane Proteins ◽  
Cytosolic Ph ◽  
Cargo Sorting

The vacuolar proton-translocating ATPase (V-ATPase) plays a major role in organelle acidification and works together with other ion transporters to maintain pH homeostasis in eukaryotic cells. We analyzed a requirement for V-ATPase activity in protein trafficking in the yeast secretory pathway. Deficiency of V-ATPase activity caused by subunit deletion or glucose deprivation results in missorting of newly synthesized plasma membrane proteins Pma1 and Can1 directly from the Golgi to the vacuole. Vacuolar mislocalization of Pma1 is dependent on Gga adaptors although no Pma1 ubiquitination was detected. Proper cell surface targeting of Pma1 was rescued in V-ATPase-deficient cells by increasing the pH of the medium, suggesting that missorting is the result of aberrant cytosolic pH. In addition to mislocalization of the plasma membrane proteins, Golgi membrane proteins Kex2 and Vrg4 are also missorted to the vacuole upon loss of V-ATPase activity. Because the missorted cargos have distinct trafficking routes, we suggest a pH dependence for multiple cargo sorting events at the Golgi.

Archaea as Global Explorers: Let`s Exchange ATPase and Occupy More Extreme Habitats!

2020 ◽  
Author(s):  
Baozhan Wang ◽  
Wei Qin
Keyword(s):  
Adaptive Radiation ◽  
Horizontal Transfer ◽  
Extreme Environments ◽  
Deep Ocean ◽  
Low Ph ◽  
Proton Pumps ◽  
Primary Control ◽  
Geothermal Systems ◽  
Ph Homeostasis ◽  
Cytosolic Ph

<p>The membrane rotary energy-yielding ATPases represent the cornerstone of cellular bioenergetics for all three domains of life. The archaeal ATPases (A-type ATPases) are functionally similar to the eukaryotic and bacterial F-type ATPases that catalyze ATP synthesis using a PMF. However, they are structurally more similar to the vacuolar-type (V-type) ATPases of eukaryotes and some bacteria that function as proton pumps driven by ATP hydrolysis. Significant variation in subunit composition, structure, and mechanism of the archaeal ATPases is thought to confer adaptive advantage in the variety of extreme environments that archaea inhabit.</p><p>The ammonia-oxidizing archaea are recognized to exert primary control of nitrification in the marine environment, are major contributors to soil nitrification, and have a habitat range extending from geothermal systems, to acidic soils and the oceanic abyss. The basis for their remarkable adaptive radiation is obscured by a relatively simple metabolism – autotrophic growth using ammonia for energy and nitrogen. In this study, we find that their adaptation to acidic habitats and the extreme pressures of the hadal zone of the ocean at depths below 6000 meters is correlated with horizontal transfer of a variant of the energy-yielding ATPase (atp) operon. Whereas the ATPase genealogy of neutrophilic soil and upper ocean pelagic AOA is congruent with their organismal genealogy inferred from concatenated conserved proteins, a common clade of V-type ATPases unites phylogenetically disparate clades of acidophilic and piezophilic species.</p><p>A function of the so-acquired V-ATPases in pumping excessive cytoplasmic protons at low pH is consistent with its increased expression by acid-tolerant AOA with decreasing pH. Consistently, heterologous expression of the thaumarchaeotal V-ATPase significantly increased the growth rate of E.coli at low pH. Additional support for adaptive significance derives from our observation that horizontal transfer is also associated with the adaptive radiation of Micrarchaeota, Parvarchaeota and Marsarchaeota into acidic environments. Their ATPases are affiliated with the acidophilic lineage ATPases of Thermoplasmatales and phylogenetically divergent from the corresponding species tree.</p><p>Another notable finding is that single hadopelagic AOA species contain both A- and V-type ATPases, suggesting that extensive horizontal transfer of atp operons is a highly active and ongoing process within AOA. The presence of an additional V-type ATPase in hadopelagic AOA may provide fitness advantages in the deep ocean with elevated hydrostatic pressure, as the proposed function of V-ATPase in pumping excessive cytoplasmic protons at high pressure may serve to maintain the cytosolic pH homeostasis in marine AOA.</p><p>Taken together, our study provides the first clear evidence of a significant role of horizontal transfer of atp operon in the adaptive radiation of AOA, one of the most successful organisms on Earth, and other archaeal species, spanning the TACK and DPANN superphyla as well as Euryarchaeota phylum.</p>

scholarly journals The Yeast Model for Batten Disease: Mutations inbtn1, btn2, and hsp30 Alter pH Homeostasis

2000 ◽  
Vol 182 (22) ◽  
pp. 6418-6423 ◽  
Author(s):  
Subrata Chattopadhyay ◽  
Neda E. Muzaffar ◽  
Fred Sherman ◽  
David A. Pearce
Keyword(s):  
Plasma Membrane ◽  
Neurodegenerative Disorder ◽  
Batten Disease ◽  
Low Ph ◽  
Ph Homeostasis ◽  
Cytosolic Ph ◽  
Poor Growth ◽  
Ph Buffering ◽  
Disease Mutations ◽  
Vacuolar Ph

ABSTRACT The BTN1 gene product of the yeast Saccharomyces cerevisiae is 39% identical and 59% similar to human CLN3, which is associated with the neurodegenerative disorder Batten disease. Furthermore, btn1-Δ strains have an elevated activity of the plasma membrane H+-ATPase due to an abnormally high vacuolar acidity during the early phase of growth. Previously, DNA microarray analysis revealed that btn1-Δ strains compensate for the altered plasma membrane H+-ATPase activity and vacuolar pH by elevating the expression of the two genesHSP30 and BTN2. We now show that deletion of either HSP30 or BTN2 in eitherBTN1 + or btn1-Δ strains does not alter vacuolar pH but does lead to an increased activity of the vacuolar H+-ATPase. Deletion of BTN1,BTN2, or HSP30 does not alter cytosolic pH but diminishes pH buffering capacity and causes poor growth at low pH in a medium containing sorbic acid, a condition known to result in disturbed intracellular pH homeostasis. Btn2p was localized to the cytosol, suggesting a role in mediating pH homeostasis between the vacuole and plasma membrane H+-ATPase. Increased expression ofHSP30 and BTN2 in btn1-Δ strains and diminished growth of btn1-Δ, hsp30-Δ, and btn2-Δ strains at low pH reinforce our view that altered pH homeostasis is the underlying cause of Batten disease.

scholarly journals A Transgene Encoding a Plasma Membrane H+-ATPase That Confers Acid Resistance in Arabidopsis thaliana Seedlings

Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 501-507
Author(s):  
Jeff C Young ◽  
Natalie D DeWitt ◽  
Michael R Sussman
Keyword(s):  
Arabidopsis Thaliana ◽  
Plasma Membrane ◽  
Large Body ◽  
Acid Resistance ◽  
Transport Systems ◽  
Proton Pumps ◽  
Ph Homeostasis ◽  
Higher Plant ◽  
Large Gene

Abstract Proton pumps (H+-ATPases) are the primary active transport systems in the plasma membrane of higher plant cells. These enzymes are encoded by a large gene family expressed throughout the plant, with specific isoforms directed to various specialized cells. While their involvement in membrane energetics has been suggested by a large body of biochemical and physiological studies, a genetic analysis of their role in plants has not yet been performed. We report here that mutant Arabidopsis thaliana plants containing a phloem-specific transgene encoding a plasma membrane H+-ATPase with an altered carboxy terminus show improved growth at low pH during seedling development. These observations provide the first genetic evidence for a role of the plasma membrane H+-ATPase in cytoplasmic pH homeostasis in plants.

scholarly journals Regulation of Cytosolic pH: The Contributions of Plant Plasma Membrane H+-ATPases and Multiple Transporters

2021 ◽  
Vol 22 (23) ◽  
pp. 12998
Author(s):  
Jin-Yan Zhou ◽  
Dong-Li Hao ◽  
Guang-Zhe Yang
Keyword(s):  
Plasma Membrane ◽  
Stress Responses ◽  
Gene Knockout ◽  
Family Members ◽  
Transport Activity ◽  
Ph Homeostasis ◽  
Transport Pathway ◽  
Cytosolic Ph ◽  
Substrate Transport ◽  
Intra Family

Cytosolic pH homeostasis is a precondition for the normal growth and stress responses in plants, and H+ flux across the plasma membrane is essential for cytoplasmic pH control. Hence, this review focuses on seven types of proteins that possess direct H+ transport activity, namely, H+-ATPase, NHX, CHX, AMT, NRT, PHT, and KT/HAK/KUP, to summarize their plasma-membrane-located family members, the effect of corresponding gene knockout and/or overexpression on cytosolic pH, the H+ transport pathway, and their functional regulation by the extracellular/cytosolic pH. In general, H+-ATPases mediate H+ extrusion, whereas most members of other six proteins mediate H+ influx, thus contributing to cytosolic pH homeostasis by directly modulating H+ flux across the plasma membrane. The fact that some AMTs/NRTs mediate H+-coupled substrate influx, whereas other intra-family members facilitate H+-uncoupled substrate transport, demonstrates that not all plasma membrane transporters possess H+-coupled substrate transport mechanisms, and using the transport mechanism of a protein to represent the case of the entire family is not suitable. The transport activity of these proteins is regulated by extracellular and/or cytosolic pH, with different structural bases for H+ transfer among these seven types of proteins. Notably, intra-family members possess distinct pH regulatory characterization and underlying residues for H+ transfer. This review is anticipated to facilitate the understanding of the molecular basis for cytosolic pH homeostasis. Despite this progress, the strategy of their cooperation for cytosolic pH homeostasis needs further investigation.

scholarly journals Potassium depletion increases proton pump (H+-ATPase) activity in intercalated cells of cortical collecting duct

2000 ◽  
Vol 279 (1) ◽  
pp. F195-F202 ◽  
Author(s):  
Randi B. Silver ◽  
Sylvie Breton ◽  
Dennis Brown
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Collecting Duct ◽  
Proton Pumps ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Acid Load ◽  
Collecting Tubules ◽  
Atpase Staining

Intercalated cells (ICs) from kidney collecting ducts contain proton-transporting ATPases (H+-ATPases) whose plasma membrane expression is regulated under a variety of conditions. It has been shown that net proton secretion occurs in the distal nephron from chronically K+-depleted rats and that upregulation of tubular H+- ATPase is involved in this process. However, regulation of this protein at the level of individual cells has not so far been examined. In the present study, H+-ATPase activity was determined in individually identified ICs from control and chronically K+-depleted rats (9–14 days on a low-K+ diet) by monitoring K+- and Na+-independent H+ extrusion rates after an acute acid load. Split-open rat cortical collecting tubules were loaded with the intracellular pH (pHi) indicator 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and pHiwas determined by using ratiometric fluorescence imaging. The rate of pHi recovery in ICs in response to an acute acid load, a measure of plasma membrane H+-ATPase activity, was increased after K+ depletion to almost three times that of controls. Furthermore, the lag time before the start of pHirecovery after the cells were maximally acidified fell from 93.5 ± 13.7 s in controls to 24.5 ± 2.1 s in K+-depleted rats. In all ICs tested, Na+- and K+-independent pHi recovery was abolished in the presence of bafilomycin (100 nM), an inhibitor of the H+-ATPase. Analysis of the cell-to-cell variability in the rate of pHi recovery reveals a change in the distribution of membrane-bound proton pumps in the IC population of cortical collecting duct from K+-depleted rats. Immunocytochemical analysis of collecting ducts from control and K+-depleted rats showed that K+-depletion increased the number of ICs with tight apical H+ATPase staining and decreased the number of cells with diffuse or basolateral H+-ATPase staining. Taken together, these data indicate that chronic K+ depletion induces a marked increase in plasma membrane H+ATPase activity in individual ICs.

Effects of bafilomycin A1 on cytosolic pH of sheep alveolar and peritoneal macrophages: evaluation of the pH-regulatory role of plasma membrane V-ATPases.

1995 ◽  
Vol 198 (8) ◽  
pp. 1711-1715 ◽  
Author(s):  
T A Heming ◽  
D L Traber ◽  
F Hinder ◽  
A Bidani
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Initial Rate ◽  
Cell Types ◽  
Peritoneal Macrophages ◽  
Bafilomycin A1 ◽  
Atpase Inhibitor ◽  
Cytosolic Ph ◽  
Phi Regulation

The role of plasma membrane V-ATPase activity in the regulation of cytosolic pH (pHi) was determined for resident alveolar and peritoneal macrophages (m theta) from sheep. Cytosolic pH was measured using 2',7'-biscarboxyethyl-5,6-carboxyfluorescein (BCECF). The baseline pHi of both cell types was sensitive to the specific V-ATPase inhibitor bafilomycin A1. Bafilomycin A1 caused a significant (approximately 0.2 pH units) and rapid (within seconds) decline in baseline pHi. Further, bafilomycin A1 slowed the initial rate of pHi recovery (dpHi/dt) from intracellular acid loads. Amiloride had no effects on baseline pHi, but reduced dpHi/dt (acid-loaded pHi nadir < 6.8) by approximately 35%. Recovery of pHi was abolished by co-treatment of m theta with bafilomycin A1 and amiloride. These data indicate that plasma membrane V-ATPase activity is a major determinant of pHi regulation in resident alveolar and peritoneal m theta from sheep. Sheep m theta also appear to possess a Na+/H+ exchanger. However, Na+/H+ exchange either is inactive or can be effectively masked by V-ATPase-mediated H+ extrusion at physiological pHi values.

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