Sequence conservation among the glucose transporter from the cyanobacterium Synechocystis sp. PCC 6803 and mammalian glucose transporters

Schmetterer, Georg

doi:10.1007/bf00016502

Cited by 43 publications

(48 citation statements)

References 38 publications

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“…Glucose Uptake Is Required for Glucose-induced Growth Inhibition of ⌬aqpZ Cells-To examine whether ⌬aqpZ cells were sensitive to intracellular or extracellular glucose, we studied the effect of deletion of the glucose uptake transporter, GlcP (42)(43)(44). Consistent with previously reported results, the ⌬glcP mutant showed strongly reduced glucose uptake from the medium (Fig.…”

Section: Deletion Of Aqpz Resulted In An Increase In Cell Volume In Tsupporting

confidence: 83%

Plasma Membrane Aquaporin AqpZ Protein Is Essential for Glucose Metabolism during Photomixotrophic Growth of Synechocystis sp. PCC 6803

Akai

Onai

Kusano

et al. 2011

Journal of Biological Chemistry

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The genome of Synechocystis PCC 6803 contains a single gene encoding an aquaporin, aqpZ. The AqpZ protein functioned as a water-permeable channel in the plasma membrane. However, the physiological importance of AqpZ in Synechocystis remains unclear. We found that growth in glucose-containing medium inhibited proper division of ⌬aqpZ cells and led to cell death. Deletion of a gene encoding a glucose transporter in the ⌬aqpZ background alleviated the glucose-mediated growth inhibition of the ⌬aqpZ cells. The ⌬aqpZ cells swelled more than the wild type after the addition of glucose, suggesting an increase in cytosolic osmolarity. This was accompanied by a down-regulation of the pentose phosphate pathway and concurrent glycogen accumulation. Metabolite profiling by GC/TOF-MS of wild-type and ⌬aqpZ cells revealed a relative decrease of intermediates of the tricarboxylic acid cycle and certain amino acids in the mutant. The changed levels of metabolites may have been the cause for the observed decrease in growth rate of the ⌬aqpZ cells along with decreased PSII activity at pH values ranging from 7.5 to 8.5. A mutant in sll1961, encoding a putative transcription factor, and a ⌬hik31 mutant, lacking a putative glucose-sensing kinase, both exhibited higher glucose sensitivity than the ⌬aqpZ cells. Examination of protein expression indicated that sll1961 functioned as a positive regulator of aqpZ gene expression but not as the only regulator. Overall, the ⌬aqpZ cells showed defects in macronutrient metabolism, pH homeostasis, and cell division under photomixotrophic conditions, consistent with an essential role of AqpZ in glucose metabolism.

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Section: Deletion Of Aqpz Resulted In An Increase In Cell Volume In Tsupporting

confidence: 83%

Plasma Membrane Aquaporin AqpZ Protein Is Essential for Glucose Metabolism during Photomixotrophic Growth of Synechocystis sp. PCC 6803

Akai

Onai

Kusano

et al. 2011

Journal of Biological Chemistry

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“…The R values of all key amino acids were below 0.05 for both nitrogen-fixation and nitratesufficient conditions, suggesting that a large fraction of the carbon in the biomass had originated from CO 2 fixation. In contrast, glucose is the most favourable carbon source for Synechocystis species (Yang et al, 2002), and the R values ( Baalen, 1978;Flores & Schmetterer, 1986;Schmetterer, 1990). So far, the presence of a glucose transporter in Cyanothece 51142 has not been rigorously verified.…”

Section: Discussion Carbon Substrate Utilization and Regulationmentioning

confidence: 99%

Mixotrophic and photoheterotrophic metabolism in Cyanothece sp. ATCC 51142 under continuous light

et al. 2010

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The unicellular diazotrophic cyanobacterium Cyanothece sp. ATCC 51142 (Cyanothece 51142) is able to grow aerobically under nitrogen-fixing conditions with alternating light-dark cycles or continuous illumination. This study investigated the effects of carbon and nitrogen sources on Cyanothece 51142 metabolism via 13 C-assisted metabolite analysis and biochemical measurements. Under continuous light (50 mmol photons m "2 s "1 ) and nitrogen-fixing conditions, we found that glycerol addition promoted aerobic biomass growth (by twofold) and nitrogenasedependent hydrogen production [up to 25 mmol H 2 (mg chlorophyll) "1 h "1 ], but strongly reduced phototrophic CO 2 utilization. Under nitrogen-sufficient conditions, Cyanothece 51142 was able to metabolize glycerol photoheterotrophically, and the activity of light-dependent reactions (e.g. oxygen evolution) was not significantly reduced. In contrast, Synechocystis sp. PCC 6803 showed apparent mixotrophic metabolism under similar growth conditions. Isotopomer analysis also detected that Cyanothece 51142 was able to fix CO 2 via anaplerotic pathways, and to take up glucose and pyruvate for mixotrophic biomass synthesis. INTRODUCTIONRising concerns about global warming due to the greenhouse effect have renewed research focused on the biological capture of CO 2 . Cyanobacteria have versatile metabolic capabilities, which allow them to grow under autotrophic, heterotrophic and mixotrophic conditions (Bottomley & Van Baalen, 1978;Eiler, 2006;Yang et al., 2002). More importantly, some cyanobacteria can capture solar energy to fix nitrogen and generate H 2 , thereby serving as a source of biofertilizer and biofuel, while simultaneously consuming atmospheric CO 2 (Bernat et al., 2009;Dutta et al., 2005;Fay, 1992;Madamwar et al., 2000;Tamagnini et al., 2007;Tuli et al., 1996). Cyanothece sp. ATCC 51142 (Cyanothece 51142), a unicellular diazotrophic cyanobacterium, is able to grow aerobically under nitrogen-fixing conditions and has been recognized as contributing to the marine nitrogen cycle. The recent sequencing of the Cyanothece 51142 genome and its transcriptional analysis have uncovered the diurnally oscillatory metabolism of the bacterium in alternating light-dark cycles (photosynthesis during the day and nitrogen fixation at night) (Stöckel et al., 2008;Toepel et al., 2008;Welsh et al., 2008). In general, cyanobacteria use spatial or temporal separation of oxygen-sensitive nitrogen fixation and oxygen-evolving photosynthesis as a strategy for diazotrophic growth (Benemann & Weare, 1974;Fay, 1992). Interestingly, Cyanothece 51142 demonstrates simultaneous N 2 fixation and O 2 evolution under continuous-light conditions, though it appears to be unicellular (Colon-Lopez et al., 1997;Huang & Chow, 1986). For example, a recent study of the transcriptional and translational regulation of continuously illuminated Cyanothece has revealed a strong synthesis capability for nitrogenase and circadian expression of 10 % of its genes (Toepel et al., 2008). Furthermore, Cyanothece str...

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“…Uptake and accumulation of sorbitol is probably the reason for the stability of the cell shape, and for the survival of cells at higher concentrations of external sorbitol, because of the equalization of the internal and external water potential compared to maltose treatment. It is known that Synechocystis is able to take up the carbohydrates glucose (Schmetterer, 1990), GG, trehalose and sucrose. The latter three solutes are transported by the salt-regulated ABC-type transporter Ggt (Mikkat et al, 1996;Mikkat & Hagemann, 2000).…”

Section: Discussionmentioning

confidence: 99%

Osmotic stress in Synechocystis sp. PCC 6803: low tolerance towards nonionic osmotic stress results from lacking activation of glucosylglycerol accumulation

et al. 2006

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In order to compare the molecular principles of the acclimatization of bacterial cells to salt and nonionic osmotic stress, the moderately halotolerant cyanobacterium Synechocystis sp. PCC 6803 was challenged by salt (NaCl), and the osmolytes sorbitol and maltose. The physiological response towards each of the three compounds was found to be different. After salt addition, the cell volume remained unchanged, and the accumulation of the osmoprotective compound glucosylglycerol (GG) was observed after activation of the key enzyme GgpS at the biochemical and gene (ggpS) expression level. Sorbitol addition had only minor effects on the cell volume. In spite of the fact that the ggpS expression was increased, the GgpS enzyme was not activated, resulting in the absence of GG accumulation. In contrast the cells accumulated sorbitol, which served as a compatible solute and assured a certain osmotic resistance. In comparison to NaCl and sorbitol, the addition of maltose caused a strong decrease in cell volume indicating water efflux. However, no osmolyte accumulation was observed, resulting in an osmosensitive phenotype. Consequently, a successful response of Synechocystis cells to an osmotic challenge is indicative of the de novo synthesis of GG upon salt-dependent activation of the GgpS enzyme or the uptake of external solutes.

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Sequence conservation among the glucose transporter from the cyanobacterium Synechocystis sp. PCC 6803 and mammalian glucose transporters

Cited by 43 publications

References 38 publications

Plasma Membrane Aquaporin AqpZ Protein Is Essential for Glucose Metabolism during Photomixotrophic Growth of Synechocystis sp. PCC 6803

Plasma Membrane Aquaporin AqpZ Protein Is Essential for Glucose Metabolism during Photomixotrophic Growth of Synechocystis sp. PCC 6803

Mixotrophic and photoheterotrophic metabolism in Cyanothece sp. ATCC 51142 under continuous light

Osmotic stress in Synechocystis sp. PCC 6803: low tolerance towards nonionic osmotic stress results from lacking activation of glucosylglycerol accumulation

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