Regulation of Vacuolar H+-ATPase (V-ATPase) Reassembly by Glycolysis Flow in 6-Phosphofructo-1-kinase (PFK-1)-deficient Yeast Cells
| Autor: | Karlett J. Parra, Chun-Yuan Chan, Dennis R. Dominguez |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Vacuolar Proton-Translocating ATPases Saccharomyces cerevisiae Proteins Phosphofructokinase-1 Saccharomyces cerevisiae Biology Biochemistry 03 medical and health sciences Membrane Biology Proton transport V-ATPase Glycolysis Phosphofructokinase 1 Molecular Biology Ethanol 030102 biochemistry & molecular biology Cell Biology Hydrogen-Ion Concentration Glucose 030104 developmental biology Vacuolar acidification Anaerobic glycolysis Steady state (chemistry) Phosphofructokinase |
| Zdroj: | Journal of Biological Chemistry. 291:15820-15829 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m116.717488 |
| Popis: | Yeast 6-phosphofructo-1-kinase (PFK-1) has two subunits, Pfk1p and Pfk2p. Deletion of Pfk2p alters glucose-dependent V-ATPase reassembly and vacuolar acidification (Chan, C. Y., and Parra, K. J. (2014) Yeast phosphofructokinase-1 subunit Pfk2p is necessary for pH homeostasis and glucose-dependent vacuolar ATPase reassembly. J. Biol. Chem. 289, 19448-19457). This study capitalized on the mechanisms suppressing vacuolar H(+)-ATPase (V-ATPase) in pfk2Δ to gain new knowledge of the mechanisms underlying glucose-dependent V-ATPase regulation. Because V-ATPase is fully assembled in pfk2Δ, and glycolysis partially suppressed at steady state, we manipulated glycolysis and assessed its direct involvement on V-ATPase function. At steady state, the ratio of proton transport to ATP hydrolysis increased 24% after increasing the glucose concentration from 2% to 4% to enhance the glycolysis flow in pfk2Δ. Tighter coupling restored vacuolar pH when glucose was abundant and glycolysis operated below capacity. After readdition of glucose to glucose-deprived cells, glucose-dependent V1Vo reassembly was proportional to the glycolysis flow. Readdition of 2% glucose to pfk2Δ cells, which restored 62% of ethanol concentration, led to equivalent 60% V1Vo reassembly levels. Steady-state level of assembly (100% reassembly) was reached at 4% glucose when glycolysis reached a threshold in pfk2Δ (≥40% the wild-type flow). At 4% glucose, the level of Pfk1p co-immunoprecipitated with V-ATPase decreased 58% in pfk2Δ, suggesting that Pfk1p binding to V-ATPase may be inhibitory in the mutant. We concluded that V-ATPase activity at steady state and V-ATPase reassembly after readdition of glucose to glucose-deprived cells are controlled by the glycolysis flow. We propose a new mechanism by which glucose regulates V-ATPase catalytic activity that occurs at steady state without changing V1Vo assembly. |
| Databáze: | OpenAIRE |
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