Singlet Oxygen Stress in Microorganisms

Glaeser, Jens; Nuss, Aaron M.; Berghoff, Bork A.; Klug, Gabriele

doi:10.1016/b978-0-12-381043-4.00004-0

Cited by 121 publications

(142 citation statements)

References 127 publications

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“…Fatty acids are targets for direct or indirect damage by ROS (1,(5)(6)(7)(8)16), particularly when ROS are produced by integral membrane enzymes in the respiratory chain or the photosynthetic apparatus (1,7,8,16,18). The R. sphaeroides σ E protein activates a transcriptional stress response to 1 O 2 , a ROS that is generated by integral membrane proteins of the photosynthetic apparatus (16,17,19). At least one ORF, which is a known member of the σ E regulon, RSP2144, encodes a protein with amino acid similarity to an enzyme predicted to modify fatty acids (16,17,(19)(20)(21).…”

Section: Resultsmentioning

confidence: 99%

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Synthesis and scavenging role of furan fatty acids

Lemke¹,

Peterson²,

Ziegelhoffer³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Fatty acids play important functional and protective roles in living systems. This paper reports on the synthesis of a previously unidentified 19 carbon furan-containing fatty acid, 10,13-epoxy-11-methyl-octadecadienoate (9-(3-methyl-5-pentylfuran-2-yl)nonanoic acid) (19Fu-FA), in phospholipids from Rhodobacter sphaeroides. We show that 19Fu-FA accumulation is increased in cells containing mutations that increase the transcriptional response of this bacterium to singlet oxygen ( 1 O 2 ), a reactive oxygen species generated by energy transfer from one or more light-excited donors to molecular oxygen. We identify a previously undescribed class of S-adenosylmethionine-dependent methylases that convert a phospholipid 18 carbon cis unsaturated fatty acyl chain to a 19 carbon methylated trans unsaturated fatty acyl chain (19M-UFA). We also identify genes required for the O 2 -dependent conversion of this 19M-UFA to 19Fu-FA. Finally, we show that the presence of 1 O 2 leads to turnover of 19Fu-Fa in vivo. We propose that furan-containing fatty acids like 19Fu-FA can act as a membrane-bound scavenger of 1 O 2 , which is naturally produced by integral membrane enzymes of the R. sphaeroides photosynthetic apparatus.radical scavenger | oxygenated fatty acid | fatty acyl methylase

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Section: Resultsmentioning

confidence: 99%

“…In this and other phototrophs, 1 O 2 is a byproduct of light energy capture in integral membrane complexes of the photosynthetic apparatus (5,16,17). Consequently, fatty acids or other membrane components are likely targets for damage by 1 O 2 (16,17).…”

mentioning

confidence: 99%

Synthesis and scavenging role of furan fatty acids

Lemke¹,

Peterson²,

Ziegelhoffer³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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“…During the intraerythrocytic phase the volume of the parasite increases up to 20-fold with respect to the invasive merozoit (22). To enable the analysis of these rapidly growing stages under comparable conditions, a new method was established in which the parasites of an asynchronous culture are categorized into three main groups.…”

Section: Discussionmentioning

confidence: 99%

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

et al. 2012

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The malaria parasite Plasmodium falciparum proliferates within human erythrocytes and is thereby exposed to a variety of reactive oxygen species (ROS) such as hydrogen peroxide, hydroxyl radical, superoxide anion, and highly reactive singlet oxygen ( 1 O 2 ). While most ROS are already well studied in the malaria parasite, singlet oxygen has been neglected to date. In this study we visualized the generation of 1 O 2 by live cell fluorescence microscopy using 3-(p-aminophenyl) fluorescein as an indicator dye. While 1 O 2 is found restrictively in the parasite, its amount varies during erythrocytic schizogony. Since the photosensitizer cercosporin generates defined amounts of 1 O 2 we have established a new cytometric method that allows the stage specific quantification of 1 O 2 . Therefore, the parasites were first classified into three main stages according to their respective pixel-area of 200-600 pixels for rings, 700-1,200 pixels for trophozoites and 1,400-2,500 pixels for schizonts. Interestingly the highest mean concentration of endogenous 1 O 2 of 0.34 nM is found in the trophozoites stage, followed by 0.20 nM (ring stage) and 0.10 nM (schizont stage) suggesting that 1 O 2 derives predominantly from the digestion of hemoglobin. ' 2012 International Society for Advancement of Cytometry

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“…Upon illumination, photosensitizer molecules such as flavin and tetrapyrroles, which are present in both phototrophic and non-phototrophic bacteria, generate highly reactive species such as 1 O 2 , which damages biomolecules (Glaeser et al, 2011). Several light-inducible genes identified in this study appear to be associated with 1 O 2 production.…”

Section: Discussionmentioning

confidence: 85%

“…Our study revealed that LitR was involved in the light-induced transcription of an extracytoplasmic function sigma factor litS that directed the transcription of crt operons (Takano et al, 2005). Interestingly, LitR homologues are widely distributed in phylogenetically divergent genera of non-phototrophic bacteria (Takano et al, 2005, 2006a, b, 2011, Ortiz-Guerrero et al, 2011, frequently flanked by genes for Crt biosynthesis and DNA photolyase (Phr).…”

Section: Introductionmentioning

confidence: 99%

LdrP, a cAMP receptor protein/FNR family transcriptional regulator, serves as a positive regulator for the light-inducible gene cluster in the megaplasmid of Thermus thermophilus

et al. 2014

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LdrP (TT_P0055) (LitR-dependent regulatory protein) is one of the four cAMP receptor protein (CRP)/FNR family transcriptional regulators retained by the extremely thermophilic bacterium Thermus thermophilus. Previously, we reported that LdrP served as a positive regulator for the light-induced transcription of crtB, a carotenoid biosynthesis gene encoded on the megaplasmid of this organism. Here, we showed that LdrP also functions as an activator of the expression of genes clustered around the crtB gene under the control of LitR, an adenosyl B12-bound light-sensitive regulator. Transcriptome analysis revealed the existence of 19 LitR-dependent genes on the megaplasmid. S1 nuclease protection assay confirmed that the promoters preceding TT_P0044 (P44), TT_P0049 (P49) and TT_P0070 (P70) were activated upon illumination in the WT strain. An ldrP mutant lost the ability to activate P44, P49 and P70, whilst disruption of litR resulted in constitutive transcription from these promoters irrespective of illumination, indicating that these genes were photo-dependently regulated by LdrP and LitR. An in vitro transcription experiment demonstrated that LdrP directly activated mRNA synthesis from P44 and P70 by the Thermus RNA polymerase holocomplex. The present evidence indicated that LdrP was the positive regulator essential for the transcription of the T. thermophilus light-inducible cluster encoded on the megaplasmid.

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Singlet Oxygen Stress in Microorganisms

Cited by 121 publications

References 127 publications

Synthesis and scavenging role of furan fatty acids

Synthesis and scavenging role of furan fatty acids

Cytometric quantification of singlet oxygen in the human malaria parasitePlasmodium falciparum

LdrP, a cAMP receptor protein/FNR family transcriptional regulator, serves as a positive regulator for the light-inducible gene cluster in the megaplasmid of Thermus thermophilus

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