Activity and Transcriptional Regulation of Bacterial Protein-Like Glycerol-3-Phosphate Dehydrogenase of the Haloarchaea in Haloferax volcanii

Rawls, Katherine S.; Martin, Jonathan H.; Maupin-Furlow, Julie A.

doi:10.1128/jb.00276-11

Cited by 28 publications

(24 citation statements)

References 32 publications

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“…The latter was reported for the overproduction of glycerol and consequently resistance to abiotic stresses. Glycerol dehydrogenase (GLYDH) is known for its effect on catalysing the oxidation of glycerol to DHA with concomitant reduction of NAD + to NADH (Ruzheinikov et al 2001;Rawls et al 2011). This confirms that the combined action of the enzymes ADH, ALDH and GLYDH is recycling of NADH : NAD + to allow continuous operation of glycerol production and metabolism.…”

Section: Introductionsupporting

confidence: 48%

Control of glycerol biosynthesis under high salt stress in Arabidopsis

Bahieldin

Sabir

Ramadan

et al. 2014

Functional Plant Biol.

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Abstract. Loss-of-function and gain-of-function approaches were utilised to detect the physiological importance of glycerol biosynthesis during salt stress and the role of glycerol in conferring salt tolerance in Arabidopsis. The salt stress experiment involved wild type (WT) and transgenic Arabidopsis overexpressing the yeast GPD1 gene (analogue of Arabidopsis GLY1 gene). The experiment also involved the Arabidopsis T-DNA insertion mutants gly1 (for suppression of glycerol 3-phosphate dehydrogenase or G3PDH), gli1 (for suppression of glycerol kinase or GK), and act1 (for suppression of G3P acyltransferase or GPAT). We evaluated salt tolerance levels, in conjunction with glycerol and glycerol 3-phosphate (G3P) levels and activities of six enzymes (G3PDH, ADH (alcohol dehydrogenase), ALDH (aldehyde dehydrogenase), GK, G3PP (G3P phosphatase) and GLYDH (glycerol dehydrogenase)) involved in the glycerol pathway. The GPD1 gene was used to overexpress G3PDH, a cytosolic NAD + -dependent key enzyme of cellular glycerol biosynthesis essential for growth of cells under abiotic stresses. T 2 GPD1-transgenic plants and those of the two mutants gli1 and act1 showed enhanced salt tolerance during different growth stages as compared with the WT and gly1 mutant plants. These results indicate that the participation of glycerol, rather than G3P, in salt tolerance in Arabidopsis. The results also indicate that the gradual increase in glycerol levels in T 2 GPD1-transgenic, and gli1 and act1 mutant plants as NaCl level increases whereas they dropped at 200 mM NaCl. However, the activities of the G3PDH, GK, G3PP and GLYDH at 150 and 200 mM NaCl were not significantly different. We hypothesise that mechanism(s) of glycerol retention/efflux in the cell are affected at 200 mM NaCl in Arabidopsis.

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Section: Introductionsupporting

confidence: 48%

Control of glycerol biosynthesis under high salt stress in Arabidopsis

Bahieldin

Sabir

Ramadan

et al. 2014

Functional Plant Biol.

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“…Halorhabdus tiamatea has all genes for anaerobic glycerol degradation: a glycerol kinase and an anaerobic glycerol‐3‐phosphate dehydrogenase ( glpABC ) (Rawls et al ., ). In Escherichia coli , the anaerobic oxidation of glycerol‐3‐phosphate to dihydroxyacetone phosphate by GlpABC is coupled to the reduction of fumarate to succinate (Schryvers and Weiner, ), but other halophilic archaea such as representatives of the genera Haloferax and Haloarcula have been shown to metabolize glycerol under anoxic conditions to D‐lactate, acetate and pyruvate (Oren and Gurevich, ).…”

Section: Resultsmentioning

confidence: 97%

Halorhabdus tiamatea: proteogenomics and glycosidase activity measurements identify the first cultivated euryarchaeon from a deep‐sea anoxic brine lake as potential polysaccharide degrader

Werner

Ferrer

Michel

et al. 2014

Environmental Microbiology

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Euryarchaea from the genus Halorhabdus have been found in hypersaline habitats worldwide, yet are represented by only two isolates: Halorhabdus utahensis AX-2T from the shallow Great Salt Lake of Utah, and Halorhabdus tiamatea SARL4BT from the Shaban deep-sea hypersaline anoxic lake (DHAL) in the Red Sea. We sequenced the H. tiamatea genome to elucidate its niche adaptations. Among sequenced archaea, H. tiamatea features the highest number of glycoside hydrolases, the majority of which were expressed in proteome experiments. Annotations and glycosidase activity measurements suggested an adaptation towards recalcitrant algal and plant-derived hemicelluloses. Glycosidase activities were higher at 2% than at 0% or 5% oxygen, supporting a preference for low-oxygen conditions. Likewise, proteomics indicated quinone-mediated electron transport at 2% oxygen, but a notable stress response at 5% oxygen. Halorhabdus tiamatea furthermore encodes proteins characteristic for thermophiles and light-dependent enzymes (e.g. bacteriorhodopsin), suggesting that H. tiamatea evolution was mostly not governed by a cold, dark, anoxic deep-sea habitat. Using enrichment and metagenomics, we could demonstrate presence of similar glycoside hydrolase-rich Halorhabdus members in the Mediterranean DHAL Medee, which supports that Halorhabdus species can occupy a distinct niche as polysaccharide degraders in hypersaline environments.

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“…Besides the PTS operon described here, H. volcanii contains a second, incomplete PTS (HVO_2101 to HVO_2104) missing the EI component, the function of which is not known (26). Further, a single HPr component, ptsH2 (HVO_1543), is present in H. volcanii, and it has been shown to be transcriptionally linked to genes involved in glycerol metabolism (26,38).…”

Section: Discussionmentioning

confidence: 99%

Fructose Degradation in the Haloarchaeon Haloferax volcanii Involves a Bacterial Type Phosphoenolpyruvate-Dependent Phosphotransferase System, Fructose-1-Phosphate Kinase, and Class II Fructose-1,6-Bisphosphate Aldolase

2012

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The halophilic archaeon Haloferax volcanii utilizes fructose as a sole carbon and energy source. Genes and enzymes involved in fructose uptake and degradation were identified by transcriptional analyses, deletion mutant experiments, and enzyme characterization. During growth on fructose, the gene cluster HVO_1495 to HVO_1499, encoding homologs of the five bacterial phosphotransferase system (PTS) components enzyme IIB (EIIB), enzyme I (EI), histidine protein (HPr), EIIA, and EIIC, was highly upregulated as a cotranscript. The in-frame deletion of HVO_1499, designated ptfC (ptf stands for phosphotransferase system for fructose) and encoding the putative fructose-specific membrane component EIIC, resulted in a loss of growth on fructose, which could be recovered by complementation in trans. Transcripts of HVO_1500 (pfkB) and HVO_1494 (fba), encoding putative fructose-1-phosphate kinase (1-PFK) and fructose-1,6-bisphosphate aldolase (FBA), respectively, as well as 1-PFK and FBA activities were specifically upregulated in fructose-grown cells. pfkB and fba knockout mutants did not grow on fructose, whereas growth on glucose was not inhibited, indicating the functional involvement of both enzymes in fructose catabolism. Recombinant 1-PFK and FBA obtained after homologous overexpression were characterized as having kinetic properties indicative of functional 1-PFK and a class II type FBA. From these data, we conclude that fructose uptake in H. volcanii involves a fructose-specific PTS generating fructose-1-phosphate, which is further converted via fructose-1,6-bisphosphate to triose phosphates by 1-PFK and FBA. This is the first report of the functional involvement of a bacterial-like PTS and of class II FBA in the sugar metabolism of archaea. Various halophilic archaea, including Haloarcula marismortui and Haloferax volcanii, have been reported to utilize fructose as carbon and energy sources (29,34,46). The pathway of fructose degradation has been studied so far mainly in the Haloarcula species H. vallismortis and H. marismortui (6,7,29). On the basis of enzyme analyses, a modified version of the Embden-Meyerhof (EM) pathway has been proposed, involving fructose phosphorylation via ketohexokinase to fructose-1-phosphate, which is further phosphorylated to fructose-1,6-bisphosphate (FBP) by fructose-1-phosphate kinase (1-PFK). FBP is subsequently cleaved by FBP aldolase (FBA) to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate, which are degraded to pyruvate following classical enzymes of the EM pathway. In vivo evidence for the operation of an EM pathway in fructose degradation was demonstrated in H. marismortui by labeling experiments with [13 C]fructose using growing cultures (29). With the same labeling techniques, glucose degradation in H. marismortui was shown to be degraded in vivo via an Entner-Doudoroff (ED) type pathway (29), which is in accordance with the proposed semiphosphorylated ED pathway for glucose degradation in haloarchaea (43).Although several enzymes of the proposed modified EM pathway...

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Activity and Transcriptional Regulation of Bacterial Protein-Like Glycerol-3-Phosphate Dehydrogenase of the Haloarchaea in Haloferax volcanii

Cited by 28 publications

References 32 publications

Control of glycerol biosynthesis under high salt stress in Arabidopsis

Control of glycerol biosynthesis under high salt stress in Arabidopsis

Halorhabdus tiamatea: proteogenomics and glycosidase activity measurements identify the first cultivated euryarchaeon from a deep‐sea anoxic brine lake as potential polysaccharide degrader

Fructose Degradation in the Haloarchaeon Haloferax volcanii Involves a Bacterial Type Phosphoenolpyruvate-Dependent Phosphotransferase System, Fructose-1-Phosphate Kinase, and Class II Fructose-1,6-Bisphosphate Aldolase

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