DNA microarrays bearing nearly all of the genes unicellular cyanobacterium Synechocystis sp PCC 6803 were used to examine temporal program gene expression during acclimation from low high light intensity. A complete pattern is provided a photosynthetic organism changing More than 160 responsive identified and classified into distinct sets. Genes involved in absorption photochemical reactions downregulated within 15 min exposure intensity, whereas those associated with CO2 fixation protection...

Whole-genome DNA microarrays were used to evaluate the effect of redox state photosynthetic electron transport chain on gene expression in Synechocystis sp. strain PCC 6803. Two specific inhibitors transport, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), added cultures, changes accumulation transcripts examined. About 140 genes highlighted as reproducibly affected by change chain. It was shown that some stress-responsive but not...

Capillary electrophoresis mass spectrometry (CE/MS) was applied for the comprehensive survey of changes in amounts metabolites upon shift from photoautotrophic to photomixotrophic conditions Synechocystis sp. PCC 6803. When glucose added photoautotrophically grown culture, increase oxidative pentose phosphate (OPP) pathway and glycolysis, together with decrease those Calvin cycle, observed. Concomitantly, respiratory activity photosynthetic took place wild-type cells. In pmgA-disrupted...

Carotenoids are important components of antioxidative systems in photosynthetic organisms. We investigated the roles zeaxanthin and echinenone protection PSII from photoinhibition Synechocystis sp. PCC 6803, using mutants cyanobacterium that lack these carotenoids. The activity mutant cells deficient either or was more sensitive to strong light than wild-type cells, both carotenoids hypersensitive light, indicating absence increased extent photoinhibition. Nonetheless, rate photodamage PSII,...

Most cyanobacterial genomes possess more than two copies of genes encoding cyAbrBs (cyanobacterial AbrB-like proteins) having an DNA-binding domain at their C-terminal region. Accumulating data suggest that a wide variety metabolic and physiologic processes are regulated by cyAbrBs. In this study, we investigated the function essential gene cyabrB1 (sll0359) in Synechocystis sp. PCC 6803 using CRISPR interference technology. The conditional knockdown caused increases cyAbrB2 transcript...

Abstract Previously, we identified a novel gene, pmgA, as an essential factor to support photomixotrophic growth of Synechocystis species PCC 6803 and reported that strain in which pmgA was deleted grew better than the wild type under photoautotrophic conditions. To gain insight into role investigated mutant phenotype detail. When low-light-grown (20 μE m−2 s−1) cells were transferred high light (HL [200μE m−2s−1]), mutants failed respond manner typically associated with Synechocystis....

Abstract Every cyanobacterial species possesses multiple genes encoding AbrB-like transcriptional regulators (cyAbrBs) distinct from those conserved among other bacterial species. In this study, two cyAbrBs in Synechocystis sp. PCC 6803, sll0359 and sll0822, were insertionally disrupted order to examine their physiological roles. A fully segregated mutant of sll0822 (Δsll0822 mutant) but not was obtained, although both mutants exhibited similar phenotypes (i.e. decreases growth rate pigment...

Summary In Synechocystis sp. strain PCC 6803, over 450 genes are upregulated following transfer of the cells from a high (1–5% CO 2 in air, HC) to low level (as air or lower, LC). This includes sbtA , ndhF3 and cmpA involved inorganic carbon (Ci) uptake. Earlier studies implicated NdhR regulation LC‐induced but there indications that additional components involved. Following extraction proteins grown under HC (NH4) SO 4 fractionation, we have identified LexA two AbrB‐like proteins, Sll0359...

All known cyanobacterial genomes possess multiple copies of genes encoding AbrB-like transcriptional regulators, as cyAbrBs, which are distinct from those conserved among other bacterial species. In this study, we addressed the physiological roles Sll0822 and Sll0359, two cyAbrBs in Synechocystis sp. strain PCC 6803, under nonstress conditions (20 μmol photons m⁻² s⁻¹ ambient CO₂). When sll0822 gene was disrupted, expression levels nitrogen-related such urtA, amt1, glnB significantly...

The repair of photosystem II (PSII) is particularly sensitive to oxidative stress and the inhibition associated with damage translational elongation system in cyanobacterium Synechocystis sp. PCC 6803. However, molecular mechanisms underlying this are unknown. We previously demonstrated vitro that EF-Tu, a translation factor delivers aminoacyl-tRNA ribosome, inactivated by reactive oxygen species via oxidation Cys residue Cys-82. In study, we examined physiological role EF-Tu Synechocystis....

We characterized the photosynthetic properties of pmgA mutant Synechocystis PCC 6803, which cannot change its photosystem stoichiometry under a high-light condition (200 µmol m–2 s–1), in order to clarify physiological significance regulation stoichiometry. found that (1) PSII activity was inhibited more wild-type cells on first day conditions than cells. (2) The growth mutants following initial imposition high light faster (3) However, severely after third exposure light. (4) inhibition...

Abstract cyAbrB is a transcriptional regulator unique to and highly conserved among cyanobacterial species. A gene-disrupted mutant of cyabrB2 (sll0822) in Synechocystis sp. PCC 6803 exhibited severe growth inhibition abnormal accumulation glycogen granules within cells under photomixotrophic conditions. Within 6 h after the shift conditions, sodium bicarbonate-dependent oxygen evolution activity markedly declined ƊcyabrB2 mutant, but decrease methyl viologen-dependent electron transport was...

Oxygenic photosynthesis requires the coordination of environmental stimuli with regulation transcription. The transcription factor RpaB is conserved from simplest unicellular cyanobacteria to complex eukaryotic algae, representing more than 1 billion years evolution. To predict RpaB-controlled regulon in cyanobacterium Synechocystis, we analyzed positional distribution binding sites together high-resolution mapping data transcriptional start (TSSs). We describe 150 target promoters whose...

In photosynthetic organisms, the repair of photosystem II (PSII) is enhanced after acclimation to strong light, with resultant mitigation photoinhibition PSII. We previously reported that oxidation translation elongation factor EF-Tu, which delivers aminoacyl-tRNA ribosome, depresses PSII in cyanobacterium Synechocystis sp. PCC 6803. present study, we investigated role EF-Tu light. cells had been grown under both and synthesis proteins de novo were Moreover, levels elevated, whereas other...

The reason(s) for glucose sensitivity in certain cyanobacterial strains is poorly understood. Inactivation of genes encoding the putative sensor kinase Hik31 Synechocystis sp. strain PCC 6803 resulted a mutant unable to grow presence d -glucose. Sensitivities -glucose, its analogue 2-deoxy- and fructose, were alleviated mutants which glcP , transporter, was inactivated. These data indicate that permeation these substrates required inflict cell death. Δ hik31 glucose-sensitive do not possess...

LexA is a well-established transcriptional repressor of SOS genes induced by DNA damage in E. coli and other bacterial species. However, the cyanobacterium Synechocystis sp. PCC 6803 has been suggested not to be involved response. In this study, we performed RNA-seq analysis wild-type strain lexA-disrupted mutant obtain comprehensive view LexA-regulated Synechocystis. Disruption lexA positively or negatively affected expression related various cellular functions such as phototactic motility,...

To avoid the photodamage, cyanobacteria regulate distribution of light energy absorbed by phycobilisome antenna either to photosystem II or I (PSI) upon high acclimation process so-called state transition. We found that an alternative PSI subunit, PsaK2 (sll0629 gene product), is involved in this cyanobacterium Synechocystis sp. PCC 6803. An examination subunit composition purified reaction center complexes revealed was absent under low condition, but incorporated into during light. The...

The coordinated high-light response of genes encoding subunits photosystem I (PSI) is achieved by the AT-rich region located just upstream core promoter in Synechocystis sp. strain PCC 6803. element enhances basal activity under low-light conditions, whereas this positive regulation lost immediately after shift to conditions. In study, we focused on a regulatory 1 (HLR1) sequence included every PSI gene examined. A gel mobility assay revealed that regulator RpaB binds HLR1 promoters. Base...

Downregulation of photosystem I (PSI) content is an essential process for cyanobacteria to grow under high-light (HL) conditions. In a pmgA (sll1968) mutant Synechocystis sp. PCC 6803, the levels PSI content, chlorophyll and transcripts psaAB genes encoding reaction-centre subunits could not be maintained low during HL incubation, although causal relationship among these phenotypes remains unknown. this study, we modulated activity transcription or that synthesis estimate their contribution...