Genes and Proteins for Solute Transport and Sensing

Ludewig, Uwe; Frommer, Wolf B.

doi:10.1199/tab.0092

Cited by 11 publications

(12 citation statements)

References 225 publications

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“…A cell can have several transporters for a solute, it can be an active transport system (ATP powered; e.g., ABC transporters), and it can have secondary active transporters working at the same time. All of these transporters may be controlled differently; some of them are constitutively expressed, some need induction for expression, and many of them are regulated by a feedback, depending on solute concentration or other factors (22). equal volume of 10% TCA, mixed with 5 ml of Opti-Fluor, and counted with a liquid scintillation analyzer as an indicator of RNA synthesis.…”

Section: Methodsmentioning

confidence: 99%

“…Transmembrane transporters of the other major class are referred to as secondary active transporters. In plants, this type of transport utilizes energy stored in the electrochemical gradient of protons across the cell membrane (22). Chlorella NC64A encodes 224 such genes, as follows: 73 amino acid, polyamine, and oligopeptide transporters; 17 nucleobase and nucleoside transporters, including PUP; 37 hexose and sugar transporters; 60 inorganic ion transporters; and 37 other secondary transporters.…”

Section: Effect Of Virus Infection On Adenine Uptakementioning

confidence: 99%

“…As in other plant cells, this negative voltage is achieved by a H ϩ ATPase, which pumps H ϩ out of the cytoplasm, and a low conductance of all passive transporters. This resulting proton motive force across the plasma membrane provides the principal driving force for solute fluxes across the plasma membrane via secondary active transporters (also referred to as secondary transporters) (22).…”

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confidence: 99%

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Chlorovirus-Mediated Membrane Depolarization ofChlorellaAlters Secondary Active Transport of Solutes

Agarkova

Dunigan

Gurnon

et al. 2008

J Virol

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Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of a family of large, double-stranded DNA, plaque-forming viruses that infect certain eukaryotic chlorella-like green algae from the genus Chlorovirus. PBCV-1 infection results in rapid host membrane depolarization and potassium ion release. One interesting feature of certain chloroviruses is that they code for functional potassium ion-selective channel proteins (Kcv) that are considered responsible for the host membrane depolarization and, as a consequence, the efflux of potassium ions. This report examines the relationship between cellular depolarization and solute uptake. Annotation of the virus host Chlorella strain NC64A genome revealed 482 putative transporter-encoding genes; 224 are secondary active transporters. Solute uptake experiments using seven radioactive compounds revealed that virus infection alters the transport of all the solutes. However, the degree of inhibition varied depending on the solute. Experiments with nystatin, a drug known to depolarize cell membranes, produced changes in solute uptake that are similar but not identical to those that occurred during virus infection. Therefore, these studies indicate that chlorovirus infection causes a rapid and sustained depolarization of the host plasma membrane and that this depolarization leads to the inhibition of secondary active transporters that changes solute uptake.

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Section: Methodsmentioning

confidence: 99%

Section: Effect Of Virus Infection On Adenine Uptakementioning

confidence: 99%

mentioning

confidence: 99%

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Chlorovirus-Mediated Membrane Depolarization ofChlorellaAlters Secondary Active Transport of Solutes

Agarkova

Dunigan

Gurnon

et al. 2008

J Virol

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“…Some of these transporters, such as VvHT3, VvHT6, and/or VvHT7 could contribute to the residual Glc uptake observed in Glc repression conditions, possibly as a result of different regulation mechanisms and/or kinetic parameters. Indeed, for a given nutrient, multiple transport systems can coexist within a single cell to assure uptake over a broad range of substrate concentrations (Ludewig and Frommer, 2002). In addition, the participation of a yet-unknown Vitis Glc transporter cannot be completely ruled out.…”

Section: Characterization Of the Hexose Transport System In Grape Celmentioning

confidence: 99%

Pathways of Glucose Regulation of Monosaccharide Transport in Grape Cells

et al. 2006

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Grape (Vitis vinifera) heterotrophic suspension-cultured cells were used as a model system to study glucose (Glc) transport and its regulation. Cells transported d-[14C]Glc according to simple Michaelis-Menten kinetics superimposed on first-order kinetics. The saturating component is a high-affinity, broad-specificity H+-dependent transport system (Km = 0.05 mm). Glc concentration in the medium tightly regulated the transcription of VvHT1 (Vitis vinifera hexose transporter 1), a monosaccharide transporter previously characterized in grape berry, as well as VvHT1 protein amount and monosaccharide transport activity. All the remaining putative monosaccharide transporters identified so far in grape were poorly expressed and responded weakly to Glc. VvHT1 transcription was strongly repressed by Glc and 2-deoxy-d-Glc, but not by 3-O-methyl-d-Glc or Glc plus mannoheptulose, indicating the involvement of a hexokinase-dependent repression. 3-O-Methyl-d-Glc, which cannot be phosphorylated, and Glc plus mannoheptulose induced a decrease of transport activity caused by the reduction of VvHT1 protein in the plasma membrane without affecting VvHT1 transcript levels. This demonstrates hexokinase-independent posttranscriptional regulation. High Glc down-regulated VvHT1 transcription and Glc uptake, whereas low Glc increased those parameters. Present data provide an example showing control of plant sugar transporters by their own substrate both at transcriptional and posttranscriptional levels. VvHT1 protein has an important role in the massive import of monosaccharides into mesocarp cells of young grape berries because it was localized in plasma membranes of the early developing fruit. Protein amount decreased abruptly throughout fruit development as sugar content increases, consistent with the regulating role of Glc on VvHT1 expression found in suspension-cultured cells.

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“…Nearly all cells in plants show self-sustained circadian oscillation, which is generated through expression of clock genes [6]. The plant cells mutually couple via the diffusion of materials in two major connections: plasmodesmata and vascular bundles (called veins in the leaf ) [7,8]. Plasmodesmata directly connect nearest-neighbor cells [9].…”

mentioning

confidence: 99%

Synchronization of Plant Circadian Oscillators with a Phase Delay Effect of the Vein Network

et al. 2007

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Synchronization phenomena in coupled circadian oscillators of plant leaves were investigated experimentally using bioluminescence technology for a clock gene. Analyzing the phase of circadian oscillation, the phase-wave propagations and the phase delay caused by the vein network were observed. We describe these phase dynamics using a two-layer model with coupled Stuart-Landau equations. Global synchronization of circadian oscillators in the leaf is also investigated.

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Genes and Proteins for Solute Transport and Sensing

Cited by 11 publications

References 225 publications

Chlorovirus-Mediated Membrane Depolarization ofChlorellaAlters Secondary Active Transport of Solutes

Chlorovirus-Mediated Membrane Depolarization ofChlorellaAlters Secondary Active Transport of Solutes

Pathways of Glucose Regulation of Monosaccharide Transport in Grape Cells

Synchronization of Plant Circadian Oscillators with a Phase Delay Effect of the Vein Network

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