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Seidel T. The Plant V-ATPase. FRONTIERS IN PLANT SCIENCE 2022; 13:931777. [PMID: 35845650 PMCID: PMC9280200 DOI: 10.3389/fpls.2022.931777] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/03/2022] [Indexed: 05/25/2023]
Abstract
V-ATPase is the dominant proton pump in plant cells. It contributes to cytosolic pH homeostasis and energizes transport processes across endomembranes of the secretory pathway. Its localization in the trans Golgi network/early endosomes is essential for vesicle transport, for instance for the delivery of cell wall components. Furthermore, it is crucial for response to abiotic and biotic stresses. The V-ATPase's rather complex structure and multiple subunit isoforms enable high structural flexibility with respect to requirements for different organs, developmental stages, and organelles. This complexity further demands a sophisticated assembly machinery and transport routes in cells, a process that is still not fully understood. Regulation of V-ATPase is a target of phosphorylation and redox-modifications but also involves interactions with regulatory proteins like 14-3-3 proteins and the lipid environment. Regulation by reversible assembly, as reported for yeast and the mammalian enzyme, has not be proven in plants but seems to be absent in autotrophic cells. Addressing the regulation of V-ATPase is a promising approach to adjust its activity for improved stress resistance or higher crop yield.
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Martínez-Salgado JL, León-Ramírez CG, Pacheco AB, Ruiz-Herrera J, de la Rosa APB. Analysis of the regulation of the Ustilago maydis proteome by dimorphism, pH or MAPK and GCN5 genes. J Proteomics 2013; 79:251-62. [PMID: 23305952 DOI: 10.1016/j.jprot.2012.12.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 10/23/2012] [Accepted: 12/30/2012] [Indexed: 11/18/2022]
Abstract
Ustilago maydis is a dimorphic corn pathogenic basidiomycota whose haploid cells grow in yeast form at pH7, while at pH3 they grow in the mycelial form. Two-dimensional gel electrophoresis (2-DE) coupled with LC-ESI/MS-MS was used to analyze the differential accumulation of proteins in yeast against mycelial morphologies. 2-DE maps were obtained in the pH range of 5-8 and 404 total protein spots were separated. From these, 43 were differentially accumulated when comparing strains FB2wt, constitutive yeast CL211, and constitutive mycelial GP25 growing at pH7 against pH3. Differentially accumulated proteins in response to pH are related with defense against reactive oxygen species or toxic compounds. Up-accumulation of CipC and down-accumulation of Hmp1 were specifically related with mycelial growth. Changes in proteins that were affected by mutation in the gene encoding the adaptor of a MAPK pathway (CL211 strain) were UM521* and transcription factors Btf3, Sol1 and Sti1. Mutation of GCN5 (GP25 strain) affected the accumulation of Rps19-ribosomal protein, Mge1-heath shock protein, and Lpd1-dihydrolipoamide dehydrogenase. Our results complement the information about the genes and proteins related with the dimorphic transition in U. maydis and changes in proteins affected by mutations in a MAPK pathway and GCN5 gene.
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Affiliation(s)
- José L Martínez-Salgado
- IPICyT, Instituto Potosino de Investigación Científica y Tecnológica. Camino a La Presa San José No. 2055, Lomas 4ª Sección, 78216, San Luis Potosí, SLP, Mexico
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Seidel T, Siek M, Marg B, Dietz KJ. Energization of vacuolar transport in plant cells and its significance under stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:57-131. [PMID: 23809435 DOI: 10.1016/b978-0-12-407696-9.00002-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant vacuole is of prime importance in buffering environmental perturbations and in coping with abiotic stress caused by, for example, drought, salinity, cold, or UV. The large volume, the efficient integration in anterograde and retrograde vesicular trafficking, and the dynamic equipment with tonoplast transporters enable the vacuole to fulfill indispensible functions in cell biology, for example, transient and permanent storage, detoxification, recycling, pH and redox homeostasis, cell expansion, biotic defence, and cell death. This review first focuses on endomembrane dynamics and then summarizes the functions, assembly, and regulation of secretory and vacuolar proton pumps: (i) the vacuolar H(+)-ATPase (V-ATPase) which represents a multimeric complex of approximately 800 kDa, (ii) the vacuolar H(+)-pyrophosphatase, and (iii) the plasma membrane H(+)-ATPase. These primary proton pumps regulate the cytosolic pH and provide the driving force for secondary active transport. Carriers and ion channels modulate the proton motif force and catalyze uptake and vacuolar compartmentation of solutes and deposition of xenobiotics or secondary compounds such as flavonoids. ABC-type transporters directly energized by MgATP complement the transport portfolio that realizes the multiple functions in stress tolerance of plants.
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Affiliation(s)
- Thorsten Seidel
- Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
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Bordag N, Keller S. α-Helical transmembrane peptides: A “Divide and Conquer” approach to membrane proteins. Chem Phys Lipids 2010; 163:1-26. [PMID: 19682979 DOI: 10.1016/j.chemphyslip.2009.07.009] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 07/21/2009] [Accepted: 07/21/2009] [Indexed: 11/26/2022]
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Duarte AMS, de Jong ER, Koehorst RBM, Hemminga MA. Conformational studies of peptides representing a segment of TM7 from H+-VO-ATPase in SDS micelles. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:639-46. [PMID: 19669749 PMCID: PMC2841257 DOI: 10.1007/s00249-009-0522-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 07/09/2009] [Accepted: 07/09/2009] [Indexed: 11/25/2022]
Abstract
The conformation of a transmembrane peptide, sMTM7, encompassing the cytoplasmic hemi-channel domain of the seventh transmembrane section of subunit a from V-ATPase from Saccharomyces cerevisiae solubilized in SDS solutions was studied by circular dichroism (CD) spectroscopy and fluorescence spectroscopy of the single tryptophan residue of this peptide. The results show that the peptide adopts an alpha-helical conformation or aggregated beta-sheet depending on the peptide-to-SDS ratio used. The results are compared with published data about a longer version of the peptide (i.e., MTM7). It is concluded that the bulky, positively charged arginine residue located in the center of both peptides has a destabilizing effect on the helical conformation of the SDS-solubilized peptides, leading to beta-sheet formation and subsequent aggregation.
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Affiliation(s)
- Afonso M. S. Duarte
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
- Present Address: Cellular Protein Chemistry Laboratory, Utrecht University, Utrecht, The Netherlands
| | - Edwin R. de Jong
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Rob B. M. Koehorst
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Marcus A. Hemminga
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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Vos WL, Schor M, Baumgaertner A, Tieleman DP, Hemminga MA. Molecular dynamics simulations reveal that AEDANS is an inert fluorescent probe for the study of membrane proteins. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:229-39. [PMID: 19669748 PMCID: PMC2795155 DOI: 10.1007/s00249-009-0527-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 07/09/2009] [Accepted: 07/22/2009] [Indexed: 11/04/2022]
Abstract
Computer simulations were carried out of a number of AEDANS-labeled single cysteine mutants of a small reference membrane protein, M13 major coat protein, covering 60% of its primary sequence. M13 major coat protein is a single membrane-spanning, α-helical membrane protein with a relatively large water-exposed region in the N-terminus. In 10-ns molecular dynamics simulations, we analyze the behavior of the AEDANS label and the native tryptophan, which were used as acceptor and donor in previous FRET experiments. The results indicate that AEDANS is a relatively inert environmental probe that can move unhindered through the lipid membrane when attached to a membrane protein.
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Affiliation(s)
- Werner L Vos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET, Wageningen, The Netherlands
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Vermeer LS, Réat V, Hemminga MA, Milon A. Structural properties of a peptide derived from H+-V-ATPase subunit a. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:1204-12. [DOI: 10.1016/j.bbamem.2009.02.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 02/10/2009] [Accepted: 02/11/2009] [Indexed: 10/21/2022]
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Duarte AMS, van Mierlo CPM, Hemminga MA. Molecular Dynamics Study of the Solvation of an α-Helical Transmembrane Peptide by DMSO. J Phys Chem B 2008; 112:8664-71. [DOI: 10.1021/jp076678j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Afonso M. S. Duarte
- Laboratory of Biophysics and Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Carlo P. M. van Mierlo
- Laboratory of Biophysics and Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Marcus A. Hemminga
- Laboratory of Biophysics and Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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Duarte AMS, Wolfs CJAM, Koehorst RBM, Popot JL, Hemminga MA. Solubilization of V-ATPase transmembrane peptides by amphipol A8-35. J Pept Sci 2008; 14:389-93. [DOI: 10.1002/psc.996] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Duarte AMS, de Jong ER, Wechselberger R, van Mierlo CPM, Hemminga MA. Segment TM7 from the cytoplasmic hemi-channel from VO-H+-V-ATPase includes a flexible region that has a potential role in proton translocation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2263-70. [PMID: 17573038 DOI: 10.1016/j.bbamem.2007.05.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 04/23/2007] [Accepted: 05/11/2007] [Indexed: 11/25/2022]
Abstract
A 900-MHz NMR study is reported of peptide sMTM7 that mimics the cytoplasmic proton hemi-channel domain of the seventh transmembrane segment (TM7) from subunit a of H(+)-V-ATPase from Saccharomyces cerevisiae. The peptide encompasses the amino acid residues known to actively participate in proton translocation. In addition, peptide sMTM7 contains the amino acid residues that upon mutation cause V-ATPase to become resistant against the inhibitor bafilomycin. 2D TOCSY and NOESY (1)H-(1)H NMR spectra are obtained of sMTM7 dissolved in d(6)-DMSO and are used to calculate the three-dimensional structure of the peptide. The NMR-based structures and corresponding dynamical features of peptide sMTM7 show that sMTM7 is composed of two alpha-helical regions. These regions are separated by a flexible hinge of two residues. The hinge acts as a ball-and-joint socket and both helical segments move independently with respect to one another. This movement in TM7 is suggested to cause the opening and closing of the cytoplasmic proton hemi-channel and enables proton translocation.
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Affiliation(s)
- Afonso M S Duarte
- Laboratory of Biophysics, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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Altamirano J, Bers DM. Voltage dependence of cardiac excitation-contraction coupling: unitary Ca2+ current amplitude and open channel probability. Circ Res 2007; 101:590-7. [PMID: 17641229 DOI: 10.1161/circresaha.107.152322] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Excitation-contraction coupling in cardiac myocytes occurs by Ca2+-induced Ca2+ release, where L-type Ca2+ current evokes a larger sarcoplasmic reticulum (SR) Ca2+ release. The Ca2+-induced Ca2+ release amplification factor or gain (SR Ca2+ release/I(Ca)) is usually assessed by the V(m) dependence of current and Ca2+ transients. Gain rises at negative V(m), as does single channel I(Ca) (i(Ca)), which has led to the suggestion that the increases of i(Ca) amplitude enhances gain at more negative V(m). However, I(Ca) = NP(o) x i(Ca) (where NP(o) is the number of open channels), and NP(o) and i(Ca) both depend on V(m). To assess how i(Ca) and NP(o) separately influence Ca2+-induced Ca2+ release, we measured I(Ca) and junctional SR Ca2+ release in voltage-clamped rat ventricular myocytes using "Ca2+ spikes" (confocal microscopy). To vary i(Ca) alone, we changed [Ca2+](o) rapidly at constant test V(m) (0 mV) or abruptly repolarized from +120 mV to different V(m) (at constant [Ca2+](o)). To vary NP(o) alone, we altered Ca2+ channel availability by varying holding V(m) (at constant test V(m)). Reducing either i(Ca) or NP(o) alone increased excitation-contraction coupling gain. Thus, increasing i(Ca) does not increase gain at progressively negative test V(m). Such enhanced gain depends on lower NP(o) and reduced redundant Ca2+ channel openings (per junction) and a consequently smaller denominator in the gain equation. Furthermore, modest i(Ca) (at V(m) = 0 mV) may still effectively trigger SR Ca2+ release, whereas at positive V(m) (and smaller i(Ca)), high and well-synchronized channel openings are required for efficient excitation-contraction coupling. At very positive V(m), reduced i(Ca) must explain reduced SR Ca2+ release.
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Affiliation(s)
- Julio Altamirano
- Department of Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 S First Ave, Maywood, IL 60153, USA
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