Role of cloned carotenoid genes expressed in Escherichia coli in protecting against inactivation by near-UV light and specific phototoxic molecules

Tuveson, R. W.; Larson, Richard A.; Kagan, Jacques

doi:10.1128/jb.170.10.4675-4680.1988

Cited by 104 publications

(64 citation statements)

References 43 publications

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“…Furthermore, it is apparent that bacteria also possess the capacity to acquire mechanisms to repair damage to DNA induced by UVR. Another protecting mechanism which may be operative is the synthesis of UV-absorbing compounds, which apparently do decrease cellular damage induced by UVR in many eucaryotic and procaryotic organisms (Dunlap et al 1986, Tuveson et al 1988, Karentz et al 1991, Garcia-Pichel & Castenholz 1993, Garcia-Pichel et al 1993, but this has not yet been studied for heterotrophic bacteria in Antarctic waters. Our data suggest that the effects of solar UVR on bacterioplankton in Antarctic waters should receive further attention, especially in regard to the mechanisms of UV-B induced damage, the degree to which cells can adapt to increased fluences of UVR, and to effects of vertical mixing processes in the upper water column.…”

Section: Discussionmentioning

confidence: 99%

Bacterioplankton viability in Antarctic waters as affected by solar ultraviolet radiation

Ew¹,

Er²,

Ve³

et al. 1995

Mar. Ecol. Prog. Ser.

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The effect of solar ultraviolet radiation (UVR) on viability of natural bactenoplankton assemblages from Antarctic waters, as well as on 2 cultures of isolated bacterial strains (Acinetobacter sp. and BaciUus sp.), was determined by both in situ and temperature-controlled incubator experiments. When natural assemblages were incubated in situ at 0.5 m depth, the mean percentage survival fractions (of the bacteria forming colonies on agar) were 13% when the sample was exposed to all UVR, 27 % when UV-B radiation was eliminated with a prefilter, and 85 % when all UVR was excluded. The magnitude of UVR-induced inhibition decreased with depth so that there was no significant inhibition at 9.5 m. There was very little effect of photosynthetically available radiation (PAR), even at 0.5 m depth. The loss of viability due to UVR or PAR was much greater for the 2 isolated strains than for the natural bacterial assemblages. Exposure of the Bacillus sp. to incident PAR, PAR + UV-A, and PAR + UV-A + UV-B resulted in survival values of 9, 0.4, and 0.1 %, respectively; when irradiance to the sample was reduced to about 3% of the ~ncident value, the corresponding values were 80. 50, and 24 %, respectively. With Acinetobactersp., the corresponding values were 60, 13, and 1.5 % with direct exposure to solar radiation, while at 1 2 % of incident radiation no inhibition by either UVR or PAR could be detected . The SOS-repair system could be induced in both bacterial strains studied with the result that the loss in viability due to UVR radiation was much reduced, but both strains still showed some loss of viability when compared to the control samples.

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Section: Discussionmentioning

confidence: 99%

Bacterioplankton viability in Antarctic waters as affected by solar ultraviolet radiation

Ew¹,

Er²,

Ve³

et al. 1995

Mar. Ecol. Prog. Ser.

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“…2) (50, 67). Accumulation of carotenoids in E. coli carrying the E. herbicola EholO crt genes requires cyclic AMP and is repressed by glucose (77,92).…”

Section: Genetics Of Carotenoid Biosynthesis In Eubacteriamentioning

confidence: 99%

“…In nonphotosynthetic organisms and tissues, carotenoids, often protein bound, occur in cytoplasmic or cell wall membranes, oil droplets, crystals, and fibrils (21,31,40). Carotenoids provide crucial protection against photooxidative damage resulting from the combination of visible or near-UV light, singlet oxygen, and endogenous lipophilic photosensitizers, such as Bchl, Chl, heme, and protoporphyrin IX (22,41,92 (21,40). During photosynthesis, carotenoids also absorb light and transfer the energy to Bchl and Chl, dissipate excess radiant energy, and preserve the structural integrity of pigment-protein complexes (22,56).…”

Section: Introductionmentioning

confidence: 99%

Eubacteria show their true colors: genetics of carotenoid pigment biosynthesis from microbes to plants

Armstrong

1994

J Bacteriol

123

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The opportunities to understand eubacterial carotenoid biosynthesis and apply the lessons learned in this field to eukaryotes have improved dramatically in the last several years. On the other hand, many questions remain. Although the pigments illustrated in Fig. 2 represent only a small fraction of the carotenoids found in nature, the characterization of eubacterial genes required for their biosynthesis has not yet been completed. Identifying those eukaryotic carotenoid biosynthetic mutants, genes, and enzymes that have no eubacterial counterparts will also prove essential for a full description of the biochemical pathways (81). Eubacterial crt gene regulation has not been studied in detail, with the notable exceptions of M. xanthus and R. capsulatus (5, 33, 39, 45, 46, 84). Determination of the rate-limiting reaction(s) in carotenoid biosynthesis has thus far yielded species-specific results (12, 27, 47, 69), and the mechanisms of many of the biochemical conversions remain obscure. Predicted characteristics of some carotenoid biosynthesis gene products await confirmation by studying the purified proteins. Despite these challenges, (over)expression of eubacterial or eukaryotic carotenoid genes in heterologous hosts has already created exciting possibilities for the directed manipulation of carotenoid levels and content. Such efforts could, for example, enhance the nutritional value of crop plants or yield microbial production of novel and desirable pigments. In the future, the functional compatibility of enzymes from different organisms will form a central theme in the genetic engineering of carotenoid pigment biosynthetic pathways.

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“…Alternatively, the envelope might be compromised by oxidative damage to integral membrane proteins or to the biosynthesis of membrane or cell wall constituents. Other (10,20,25,28,38), but the site and nature of the causative lesion(s) were not determined.…”

Section: Methodsmentioning

confidence: 99%

Suppression of oxidative envelope damage by pseudoreversion of a superoxide dismutase-deficient mutant of Escherichia coli

Imlay

Fridovich

1992

J Bacteriol

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Mutants of Escherichia coli that are devoid of superoxide dismutase (SOD) fail to grow in aerobic minimal medium. This is largely because of the O2 sensitivities of several amino acid biosynthetic pathways, since amino acid supplements can restore growth, albeit at a slow rate. We now report that growth in amino acid-supplemented medium can be further stimulated by the presence of extracellular osmolytes. Osmolytes also partially suppress the amino acid requirements of the SOD mutant. These data suggest that the combination of oxidative inj]ury and turgor pressure permeabilizes the cell envelope and that critical metabolites, including the limiting products of damaged biosynthetic pathways, escape from the cell. External osmolytes may offer protection by countervailing the usual turgor pressure and thus stabilizing the damaged envelope. This model is consistent with the previous observation that deficiency of cell wall components is lethal to SOD mutants. A pseudorevertant that can grow at a moderate rate in normosmotic medium without amino acid supplementation has been obtained (J. A. Imlay and I. Fridovich, Mol. Gen. Genet. 228:410-416, 1991). Analysis suggests that the suppressor mutation allows the envelope either to resist or to tolerate oxidative lesions. Study of the pseudorevertant may illuminate the molecular basis of this oxidative envelope injury.

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Role of cloned carotenoid genes expressed in Escherichia coli in protecting against inactivation by near-UV light and specific phototoxic molecules

Cited by 104 publications

References 43 publications

Bacterioplankton viability in Antarctic waters as affected by solar ultraviolet radiation

Bacterioplankton viability in Antarctic waters as affected by solar ultraviolet radiation

Eubacteria show their true colors: genetics of carotenoid pigment biosynthesis from microbes to plants

Suppression of oxidative envelope damage by pseudoreversion of a superoxide dismutase-deficient mutant of Escherichia coli

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