Subunit composition and Ca2+-ATPase activity of the vacuolar ATPase from barley roots

DuPont, Frances M.; Morrissey, Peter J.

doi:10.1016/0003-9861(92)90693-q

Cited by 30 publications

(7 citation statements)

References 32 publications

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“…The complex structure of V-type ATPases as being composed of at least 10 electrophoretically distinct polypeptides was deduced from SDS-PAGE separations of purified VATPase as early as in 1992 by Ward andSze, 1992 for oat, andDuPont andMorrissey (1992) for barley. The first sequence information on V-ATPase subunits was obtained for vha -A , -B and -c (Manolson et al 1988, Zimniak et al 1988, Lai et al 1991.…”

Section: Discussionmentioning

confidence: 99%

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

Kluge

Lamkemeyer

Tavakoli

et al. 2003

Molecular Membrane Biology

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The vacuolar-type ATPase (V-ATPase) and the vacuolar H(+)-pyrophosphatase are electrogenic proton pumps at plant endomembranes that create the proton motive force required for secondary activated transport and metabolite accumulation during development and adaptation to a variety of adverse growth conditions. Twelve distinct vacuolar H(+)-ATPase (VHA) subunits are suggested to constitute the functional V-ATPase complex. Starting from the available expressed sequence tag (EST) sequences and by homology screening, the complete set of 12 VHA subunits was cloned as cDNAs from the halophyte Mesembryanthemum crystallinum, vha-A-H, -a,-c, -d and -e. Transcript levels of all 12 VHA subunits as well as of tonoplast pyrophosphatase and P-ATPase were analysed in root and leaf tissue under conditions of osmotic (700 mM mannitol), heat and cold stress, and salinity. Distinct coordinated changes of stress-induced expression were observed for most subunits in roots and leaves, with mostly paralleled changes in transcript levels of all subunits. In some cases, contrasting responses were seen for vha-B and -c transcript amounts.

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Section: Discussionmentioning

confidence: 99%

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

Kluge

Lamkemeyer

Tavakoli

et al. 2003

Molecular Membrane Biology

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“…According to membrane fractionation studies, the V-ATPase associaíed with smooth ER and low-density endomembranes in oat or com seedlings is a functional proton pump. Membranes equilibrating between 24 and 28% Suc show both vanadatesensitive and nitrate-sensitive ATPase activity (ChL rchill et al, 1983) and are active in proton pumping (DuPont et al, 1982; Hager and Biber, 1984) or in ApH-driven Ca transport (Schumaker and Sze, 1985). (b) Are all the endomvmbrane V-ATPases destined for the mature vacuole or are they sorted to specific destinations?…”

Section: Discussionmentioning

confidence: 99%

Vacuolar-Type H+ -ATPases Are Associated with the Endoplasmic Reticulum and Provacuoles of Root Tip Cells

Herman

et al. 1994

Plant Physiol.

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To understand the origin of vacuolar H+-ATPases (V-ATPases) and their cellular functions, the subcellular location of V-H+-ATPases was examined immunologically in root cells of oat seedlings. A V-ATPase complex from oat roots consists of a large peripheral sector (V,) that includes the 70-kD (A) catalytic and the 60-kD (6) regulatory subunits. The soluble V1 complex, thought to be synthesized in the cytoplasm, is assembled with the membrane integral sector (V.) at a yet undefined location. In mature cells, VATPase subunits A and B, detected in immunoblots with mqnoclonal antibodies (Mab) (7A5 and 2E7), were associated mainly with vacuolar membranes (20-22% sucrose) fractionated with an isopycnic sucrose gradient. However, in immature root tip cells, which lack large vacuoles, most of the V-ATPase was localized with the endoplasmic reticulum (ER) at 28 to 31% sucrose where a major ER-resident binding protein equilibrated. The peripheral subunits were also associated with membranes at 22% sucrose, at 31 to 34% sucrose (Golgi), and in plasma membranes at 38% sucrose. lmmunogold labeling of root tip cells with Mab 2E7 against subunit B showed gold particles decorating the ER as well as numerous small vesicles (0.1-0.3 pm diameter), presumably provacuoles. The immunological detection of the peripheral subunit B on the ER supports a model in which the V1 sector is assembled with the V , , on the ER. These results support the model in which the central vacuolar membrane originates ultimately from the ER. The presence of V-ATPases on several endomembranes indicates that this pump could participate in diverse functional roles.In plants, acidification of the vacuolar compartment by the V-ATPase is essential to or involved in many diverse functions (Sze et al., 1992a). Depending on the tissue, the stage of development, and the signals received, these functions include osmoregulation, transport and storage of ions and metabolites, signal transduction, storage and turnover of proteins, and storage of secondary metabolites, defense proteins, and pigments (Boller and Wiemken, 1986;Martinoia, 1992). Vacuoles are dynamic, prominent organelles. Undifferentiated and immature plant cells often possess proportionately more cytoplasm that contains an extensive endo-

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“…The 16-kD subunit is a proteolipid that binds DCCD (an inhibitor of V-type ATPases) and is present in six copies in the integral sector (4,12). The plant V-type H+-ATPases purified from either red beet storage tissue (17), mung bean hypocotyl (13), barley roots (9), or oat roots (18,24) contain 9 or 10 subunits. Hence, the plant V-type H+-ATPase is similar in subunit complexity to those of other eukaryotic sources (10).…”

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Proton Transport Activity of the Purified Vacuolar H⁺-ATPase from Oats

Ward

Sze

1992

Plant Physiol.

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To determine whether the detergent-solubilized and purified vacuolar H'-ATPase from plants was active in HW transport, we reconstituted the purified vacuolar ATPase from oat roots (Avena sativa var Lang). Triton-solubilized ATPase activity was purified by gel filtration and ion exchange chromatography. Incorporation of the vacuolar ATPase into liposomes formed from Escherichia coli phospholipids was accomplished by removing Triton X-100 with SM-2 Bio-beads. ATP of 70, 60, 44, 42, 36, 32, 29, 16, 13, and 12 kilodaltons. These results demonstrate conclusively that the purified vacuolar ATPase is a functional electrogenic H' pump and that a set of 10 polypeptides is sufficient for coupled ATP hydrolysis and H' translocation.An electrogenic H+-ATPase2 is located in the vacuolar membrane of higher plant cells (20 V-type H+-ATPases are large and multimeric and composed of a peripheral (cytoplasmic) sector containing the ATP hydrolytic site and a membrane integral sector that forms the proton transport pathway. Three major subunits are common to all V-type ATPases. The 70-and 60-kD subunits are present in three copies each in the peripheral sector (4), contain nucleotide-binding sites, and are thought to have catalytic and regulatory roles, respectively. The 16-kD subunit is a proteolipid that binds DCCD (an inhibitor of V-type ATPases) and is present in six copies in the integral sector (4, 12). The plant V-type H+-ATPases purified from either red beet storage tissue (17), mung bean hypocotyl (13), barley roots (9), or oat roots (18, 24) contain 9 or 10 subunits. Hence, the plant V-type H+-ATPase is similar in subunit complexity to those of other eukaryotic sources (10).The purified vacuolar H+-ATPase (650 kD) from oat roots contains 10 subunits, with molecular masses of 70, 60, 44, 42, 36, 32, 29, 16, 13, and 12 kD (24). Six of these constitute the large peripheral sector, and the remaining four polypeptides of 32, 16, 13, and 12 kD make up the integral sector. The large peripheral sector is visible as a knob and stalk structure on the surface of tonoplast vesicles (24). The peripheral complex of the enzyme can be dissociated from the integral portion by chaotropic anions, such as I-and NO3-, which decrease both ATP hydrolytic and H+ transport activities. However, we have recently shown that the dissociated and inactive H+-ATPase from oat can be reassembled to produce a fully functional H+-translocating ATPase (22).Although V-type H+-ATPases from several plant sources have been purified, H+ transport of a purified plant H+-ATPase has not been previously demonstrated. To test whether the purified H+-ATPase from oats retained H+ transport activity and to study the regulation of the H+-ATPase 925 www.plantphysiol.org on May 11, 2018 -Published by Downloaded from

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Subunit composition and Ca2+-ATPase activity of the vacuolar ATPase from barley roots

Cited by 30 publications

References 32 publications

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

Vacuolar-Type H+ -ATPases Are Associated with the Endoplasmic Reticulum and Provacuoles of Root Tip Cells

Proton Transport Activity of the Purified Vacuolar H⁺-ATPase from Oats

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Subunit composition and Ca2+-ATPase activity of the vacuolar ATPase from barley roots

Cited by 30 publications

References 32 publications

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

cDNA cloning of 12 subunits of the V-type ATPase from Mesembryanthemum crystallinum and their expression under stress

Vacuolar-Type H+ -ATPases Are Associated with the Endoplasmic Reticulum and Provacuoles of Root Tip Cells

Proton Transport Activity of the Purified Vacuolar H+-ATPase from Oats

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Proton Transport Activity of the Purified Vacuolar H⁺-ATPase from Oats