Comparison of salt- and heat-induced alterations of protein synthesis in the cyanobacterium Synechocystis sp. PCC 6803

Hagemann, Martin; Techel, Dieter; Rensing, Ludger

doi:10.1007/bf00245354

Cited by 45 publications

(20 citation statements)

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“…Until now most of the proteins induced by salt stress were unknown. Many of them were also found after other stress treatments, therefore they can be regarded as general stress proteins (Fulda et al, 1999 ;Hagemann et al, 1991). The specific effect of salt, demonstrated in the phenotype of the SigF mutant, provides evidence that SigF represents a terminal element of a signal-transducing pathway sensing salt.…”

Section: Discussionmentioning

confidence: 96%

“…Since most saltstress proteins of Synechocystis are only transiently detectable (Hagemann et al, 1991), it may be concluded that those proteins are only important during the early acclimation phase. Therefore, investigations of the early salt acclimation process were performed using WT and SigF mutant cells (Fig.…”

Section: Salt Tolerance Of the Sigf Mutantmentioning

confidence: 99%

“…Fulda et al, 1999 ;Hagemann et al, 1991 ;Webb & Sherman, 1994). These stress proteins can be divided into two groups, special stress proteins, which are only induced by a defined stress, and general stress proteins, which are induced by several stresses (Hagemann et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

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Stress responses of Synechocystis sp. strain PCC 6803 mutants impaired in genes encoding putative alternative sigma factors

et al. 2000

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In the complete genome sequence of the cyanobacterium Synechocystis sp. strain PCC 6803 [Kaneko et al. (1996). DNA Res 3, 109-136] genes were identified encoding putative group 3 σ-factors SigH (Sll-0856), SigG (Slr-1545) and SigF (Slr-1564) and the regulatory protein RsbU (Slr-2031). Mutations in these genes were generated by interposon mutagenesis to study their importance in stress acclimation. For the genes sigH, sigF and rsbU, the loci segregated completely. However, attempts to mutagenize the sigG locus resulted in merodiploids. Under standard growth conditions only minor differences were detected between the mutants and wild-type. However, cells of the RsbU mutant showed a clear defect in regenerating growth after a nitrogen-and sulphur-starvation-induced stationary phase. After applying salt, heat and high-light shocks, stress protein synthesis was analysed by means of one-and two-dimensional electrophoresis. Cells of the SigF mutant showed a severe defect in the induction of salt stress proteins. Although the acclimation to moderate salt stress up to 684 mM NaCl was not significantly changed in this mutant, its ability to acclimate to higher concentrations of NaCl was reduced. Northern blot experiments showed a constitutive expression of the rsbU and sigF genes. The expression of the sigH gene was found to be stressstimulated, particularly in heat-shocked cells, whilst that of sigG was transiently decreased under stress conditions. Possible functions of these regulatory proteins in stress acclimation of Synechocystis cells are discussed.

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Section: Discussionmentioning

confidence: 96%

Section: Salt Tolerance Of the Sigf Mutantmentioning

confidence: 99%

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Stress responses of Synechocystis sp. strain PCC 6803 mutants impaired in genes encoding putative alternative sigma factors

et al. 2000

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“…PCC 6803 cells has been shown by Hagemann et al (1991). They demonstrated that salt stress by NaCl reduced the synthesis of most proteins to approximately 30% to 35% of the control level but specifically increased the synthesis of several proteins that might be related to salt stress.…”

Section: Protective Effects Of Light On the Nacl-induced Inactivationmentioning

confidence: 97%

Unsaturated Fatty Acids in Membrane Lipids Protect the Photosynthetic Machinery against Salt-Induced Damage inSynechococcus

et al. 2001

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In this study, the tolerance to salt stress of the photosynthetic machinery was examined in relation to the effects of the genetic enhancement of the unsaturation of fatty acids in membrane lipids in wild-type and desA ϩ cells of Synechococcus sp. PCC 7942. Wild-type cells synthesized saturated and mono-unsaturated fatty acids, whereas desA ϩ cells, which had been transformed with the desA gene for the ⌬12 acyl-lipid desaturase of Synechocystis sp. PCC 6803, also synthesized diunsaturated fatty acids. Incubation of wild-type and desA ϩ cells with 0.5 m NaCl resulted in the rapid loss of the activities of photosystem I, photosystem II, and the Na ϩ /H ϩ antiport system both in light and in darkness. However, desA ϩ cells were more tolerant to salt stress and osmotic stress than the wild-type cells. The extent of the recovery of the various photosynthetic activities from the effects of 0.5 m NaCl was much greater in desA ϩ cells than in wild-type cells. The photosystem II activity of thylakoid membranes from desA ϩ cells was more resistant to 0.5 m NaCl than that of membranes from wild-type cells. These results demonstrated that the genetically engineered increase in unsaturation of fatty acids in membrane lipids significantly enhanced the tolerance of the photosynthetic machinery to salt stress. The enhanced tolerance was due both to the increased resistance of the photosynthetic machinery to the salt-induced damage and to the increased ability of desA ϩ cells to repair the photosynthetic and Na ϩ /H ϩ antiport systems.Salt stress is one of the main environmental factors that limit the growth and productivity of plants and micro-organisms. We have been investigating the mechanisms of the hyperosmotic stress-induced and the salt stress-induced inactivation of the photosynthetic machinery, focussing on the oxygen-evolving machinery of the photosystem II complex, which is the system that is most susceptible to such environmental stress in Synechococcus sp. PCC 7942 (hereafter Synechococcus; Allakhverdiev et al., 2000aAllakhverdiev et al., , 2000b. Hyperosmotic stress due to 1.0 m sorbitol induces the efflux of water through water channels and reduces the volume of cells by more than 50%. This loss of water from the cytosol might be expected to increase the intracellular concentration of salts, and it leads to the rapid but reversible inactivation of the oxygenevolving machinery (Allakhverdiev et al., 2000b).Salt stress due to 0.5 m NaCl has both osmotic and ionic effects (Allakhverdiev et al., 2000a). The osmotic effect due to 0.5 m NaCl is not as strong as the effect of 1.0 m sorbitol and inactivates reversibly the oxygen-evolving machinery. The ionic effect of 0.5 m NaCl is caused by the influx of Na ϩ ions through K ϩ (Na ϩ ) channels and the resultant increase in the intracellular concentration of Na ϩ ions and counterpart anions that are mostly Cl Ϫ ions (Allakhverdiev et al., 2000a). These changes result in the irreversible inactivation of the oxygen-evolving machinery. As a consequence salt stress appears t...

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“…A comparison of the proteins highlighted here with those displaying di¡erential rates of synthesis in heat-and salt-shocked cells of Synechocystis PCC6803 has revealed a larger span of changes in the latter case [24]. Tentative comparisons from 2-D gel migration patterns in cells submitted to the di¡er-ent treatments did not reveal, within the limits of such comparisons, any general stress protein being a¡ected by the changes in Ci regime, and indicated that at least proteins I-1, I-2, I-5 and I-6 are not highlighted in salt-or heat-shocked cells.…”

Section: Protein Pattern During Stationary Phase Of Growthmentioning

confidence: 99%

Variations of protein profiles upon shifts in inorganic carbon regime in the cyanobacterium Synechocystis PCC6803

Maestri

1998

FEMS Microbiology Letters

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Reversible changes between limiting and high inorganic carbon regimes in Synechocystis PCC6803 maintained overall protein synthesis at a high level. The protein patterns of cells during or after adaptation to these regimes were detected by pulse labelling and identification after one-dimensional and two-dimensional electrophoreses. Several particular patterns were observed. Proteins specific for either the high or the limiting carbon conditions could be identified. The protein profiles of cells having reached the stationary phase of growth clearly differed from those of their exponentially growing counterparts. Accumulation of Rubisco, the key enzyme of the Calvin cycle, was not modified in the conditions tested. z

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Comparison of salt- and heat-induced alterations of protein synthesis in the cyanobacterium Synechocystis sp. PCC 6803

Cited by 45 publications

References 19 publications

Stress responses of Synechocystis sp. strain PCC 6803 mutants impaired in genes encoding putative alternative sigma factors

Stress responses of Synechocystis sp. strain PCC 6803 mutants impaired in genes encoding putative alternative sigma factors

Unsaturated Fatty Acids in Membrane Lipids Protect the Photosynthetic Machinery against Salt-Induced Damage inSynechococcus

Variations of protein profiles upon shifts in inorganic carbon regime in the cyanobacterium Synechocystis PCC6803

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