SdrA, an NADP(H)‐regenerating enzyme, is crucial for
            <i>Coxiella burnetii</i>
            to resist oxidative stress and replicate intracellularly

Bitew, Mebratu A; Hofmann, Janine; Souza, David P De; Wawegama, Nadeeka K.; Newton, Hayley J; Sansom, Fiona M.

doi:10.1111/cmi.13154

Cited by 12 publications

(10 citation statements)

References 38 publications

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“…Additionally, TCA cycle derivates aspartate and glutamate had lower label inclusion levels, suggesting the decreased fraction labelling continued into these derivative biosynthesis pathways as well. The M+2 isotopologue was most prevalent through detected TCA cycle intermediates (S5 Fig), supporting previous findings of carbon entering the TCA cycle via a fully labelled acetyl-CoA intermediate [7,70].…”

Section: Loss Of Cbu0823 Alters Central Carbon Metabolism Of C Burnetiisupporting

confidence: 89%

“…The MDH-PckA pathway may provide sufficient OAA and PEP to maintain typical C. burnetii replication, especially as the normal replication rate of C. burnetii is comparatively slow [77]. Furthermore, reduction in TCA cycle activity reduces oxidative stress, an issue for C. burnetii within its replicative niche [6,70], and the reduced TCA activity may be of benefit to the 0823::Tn mutant. Moreover, this study concentrates on glucose utilization whereas C. burnetii has a metabolism capable of utilizing amino acids, thus the additional energy required by the 0823::Tn mutant for replication could be provided by carbon sources other than glucose [7,79].…”

Section: Plos Onementioning

confidence: 99%

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Characterisation of putative lactate synthetic pathways of Coxiella burnetii

et al. 2021

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The zoonotic pathogen Coxiella burnetii, the causative agent of the human disease Q fever, is an ever-present danger to global public health. Investigating novel metabolic pathways necessary for C. burnetii to replicate within its unusual intracellular niche may identify new therapeutic targets. Recent studies employing stable isotope labelling established the ability of C. burnetii to synthesize lactate, despite the absence of an annotated synthetic pathway on its genome. A noncanonical lactate synthesis pathway could provide a novel anti-Coxiella target if it is essential for C. burnetii pathogenesis. In this study, two C. burnetii proteins, CBU1241 and CBU0823, were chosen for analysis based on their similarities to known lactate synthesizing enzymes. Recombinant GST-CBU1241, a putative malate dehydrogenase (MDH), did not produce measurable lactate in in vitro lactate dehydrogenase (LDH) activity assays and was confirmed to function as an MDH. Recombinant 6xHis-CBU0823, a putative NAD+-dependent malic enzyme, was shown to have both malic enzyme activity and MDH activity, however, did not produce measurable lactate in either LDH or malolactic enzyme activity assays in vitro. To examine potential lactate production by CBU0823 more directly, [13C]glucose labelling experiments compared label enrichment within metabolic pathways of a cbu0823 transposon mutant and the parent strain. No difference in lactate production was observed, but the loss of CBU0823 significantly reduced 13C-incorporation into glycolytic and TCA cycle intermediates. This disruption to central carbon metabolism did not have any apparent impact on intracellular replication within THP-1 cells. This research provides new information about the mechanism of lactate biosynthesis within C. burnetii, demonstrating that CBU1241 is not multifunctional, at least in vitro, and that CBU0823 also does not synthesize lactate. Although critical for normal central carbon metabolism of C. burnetii, loss of CBU0823 did not significantly impair replication of the bacterium inside cells.

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Section: Loss Of Cbu0823 Alters Central Carbon Metabolism Of C Burnetiisupporting

confidence: 89%

Section: Plos Onementioning

confidence: 99%

Characterisation of putative lactate synthetic pathways of Coxiella burnetii

et al. 2021

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“…In addition, CLEOA does not encode genes for an acid phosphatase and two sterol reductases that likely modify host proteins and cholesterol, respectively, to protect C. burnetii from host-induced oxidative stress ( Seshadri et al 2003 ; Gilk et al 2010 ; Hill and Samuel 2011 ; Gilk 2012 ). Finally, C. burnetii is thought to compensate for the lack of the oxidative branch of pentose phosphate pathway (PPP)—a major source of NADPH, by utilizing alternative NADPH-regenerating enzymes such as short-chain dehydrogenases and sterol reductases, and by salvaging NAD + from the host ( Bitew et al 2018 , 2020 ). In CLEOA, all four short-chain dehydrogenases, the two eukaryote-like sterol reductases, and the nicotinate-salvaging protein have become nonfunctional.…”

Section: Resultsmentioning

confidence: 99%

Coxiella burnetii and Related Tick Endosymbionts Evolved from Pathogenic Ancestors

Brenner

Muñoz-Léal

Sachan

et al. 2021

Genome Biology and Evolution

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Both symbiotic and pathogenic bacteria in the family Coxiellaceae cause morbidity and mortality in humans and animals. For instance, Coxiella-like endosymbionts (CLEs) improve the reproductive success of ticks — a major disease vector, while Coxiella burnetii causes human Q fever, and uncharacterized coxiellae infect both animals and humans. To better understand the evolution of pathogenesis and symbiosis in this group of intracellular bacteria, we sequenced the genome of a CLE present in the soft tick Ornithodoros amblus (CLEOA) and compared it to the genomes of other bacteria in the order Legionellales. Our analyses confirmed that CLEOA is more closely related to C. burnetii, the human pathogen, than to CLEs in hard ticks, and showed that most clades of CLEs contain both endosymbionts and pathogens, indicating that several CLE lineages have evolved independently from pathogenic Coxiella. We also determined that the last common ancestor of CLEOA and C. burnetii was equipped to infect macrophages, and that even though horizontal gene transfer (HGT) contributed significantly to the evolution of C. burnetii, most acquisition events occurred primarily in ancestors predating the CLEOA-C. burnetii divergence. These discoveries clarify the evolution of C. burnetii, which previously was assumed to have emerged when an avirulent tick endosymbiont recently gained virulence factors via HGT. Finally, we identified several metabolic pathways, including heme biosynthesis, that are likely critical to the intracellular growth of the human pathogen but not the tick symbiont, and show that the use of heme analog is a promising approach to controlling C. burnetii infections.

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“…Of significance, the short-chain dehydrogenase SdrA (CBU1276, C. burnetii RSA493) was recently identified as a physiologically significant NADPH-regenerating enzyme in C. burnetii (Bitew et al . 2020 ). Predicted proteins with similarity to SdrA are found in other organisms, suggesting SdrA-dependent regeneration of NADPH is not unique to C. burnetii .…”

Section: Discussionmentioning

confidence: 99%

Conditional impairment of Coxiella burnetii by glucose-6P dehydrogenase activity

Sanchez

Omsland

2021

Pathogens and Disease

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Coxiella burnetii is a bacterial obligate intracellular parasite and the etiological agent of Query (Q) fever. While the C. burnetii genome has been reduced to approximately 2 Mb as a likely consequence of genome streamlining in response to parasitism, components for a nearly complete central metabolic machinery are encoded by the genome. However, lack of a canonical hexokinase for phosphorylation of glucose and an apparent absence of the oxidative branch of the pentose phosphate pathway, a major mechanism for regeneration of the reducing equivalent NADPH, have been noted as potential metabolic limitations of C. burnetii. By complementing C. burnetii with the zwf gene encoding the glucose-6-phosphate (G6P)-consuming and NADPH-producing enzyme glucose 6-phosphate dehydrogenase (G6PD), we demonstrate a severe metabolic fitness defect for C. burnetii under conditions of glucose limitation. Supplementation of the medium with the gluconeogenic carbon source glutamate did not rescue the growth defect of bacteria complemented with zwf. Absence of G6PD in C. burnetii therefore likely relates to the negative effect of its activity under conditions of glucose limitation. C. burnetii central metabolism with emphasis on glucose, NAD+, NADP+ and NADPH is discussed in a broader perspective, including comparisons to other bacterial obligate intracellular parasites.

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SdrA, an NADP(H)‐regenerating enzyme, is crucial for Coxiella burnetii to resist oxidative stress and replicate intracellularly

Cited by 12 publications

References 38 publications

Characterisation of putative lactate synthetic pathways of Coxiella burnetii

Characterisation of putative lactate synthetic pathways of Coxiella burnetii

Coxiella burnetii and Related Tick Endosymbionts Evolved from Pathogenic Ancestors

Conditional impairment of Coxiella burnetii by glucose-6P dehydrogenase activity

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