Global proteomic characterization of photosystem II complexes from Synechocystis 6803
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ABSTRACT:
ORGANISM(S): Synechocystis sp. PCC 6803
PROVIDER: GSE9577 | GEO | 2008/08/18
SECONDARY ACCESSION(S): PRJNA103405
REPOSITORIES: GEO
Similar Datasets
Project description:Photosystem II (PSII) is the most thermally sensitive component of photosynthesis. Thermal acclimation of this complex activity is likely to be critically important to the ability of photosynthetic organisms to tolerate temperature changes in the environment. We have analysed gene expression using whole-genome microarrays and monitored alterations in physiology during acclimation of PSII to elevated growth temperature in Synechocystis sp. PCC 6803. PSII acclimation is complete within 480 minutes of exposure to elevated temperature and is associated with a highly dynamic transcriptional response. 176 genes were identified and classified into seven distinct response profile groups. Response profiles suggest the existence of an early transient phase and a sustained phase to the acclimation response. The early phase was characterised by induction of general stress response genes, including heat shock proteins, which are likely to influence PSII thermal stability. The sustained phase consisted of acclimation-specific alterations that are involved in other cellular processes. Sustained responses included genes involved in phycobillisome structure and modification, photosynthesis, respiration, lipid metabolism and motility. Approximately 60% of genes with sustained altered expression levels have no known function. The potential role of differentially expressed genes in thermotolerance and acclimation is discussed. We have characterised the acclimation physiology of selected gene ‘knockouts’ to elucidate possible gene function in the response. All mutants show lower PSII rates under normal growth conditions. Basal PSII thermotolerance was affected by mutations in clpB1, cpcC2, hspA, htpG and slr1674. Final PSII thermotolerance was affected by mutations in cpcC2, hik34, hspA and hypA1, suggesting that these gene products play roles in long-term thermal acclimation of PSII.
2010-04-09 | GSE21133 | GEO
Project description:Photosystem II (PSII) is the most thermally sensitive component of photosynthesis. Thermal acclimation of this complex activity is likely to be critically important to the ability of photosynthetic organisms to tolerate temperature changes in the environment. We have analysed gene expression using whole-genome microarrays and monitored alterations in physiology during acclimation of PSII to elevated growth temperature in Synechocystis sp. PCC 6803. PSII acclimation is complete within 480 minutes of exposure to elevated temperature and is associated with a highly dynamic transcriptional response. 176 genes were identified and classified into seven distinct response profile groups. Response profiles suggest the existence of an early transient phase and a sustained phase to the acclimation response. The early phase was characterised by induction of general stress response genes, including heat shock proteins, which are likely to influence PSII thermal stability. The sustained phase consisted of acclimation-specific alterations that are involved in other cellular processes. Sustained responses included genes involved in phycobillisome structure and modification, photosynthesis, respiration, lipid metabolism and motility. Approximately 60% of genes with sustained altered expression levels have no known function. The potential role of differentially expressed genes in thermotolerance and acclimation is discussed. We have characterised the acclimation physiology of selected gene ‘knockouts’ to elucidate possible gene function in the response. All mutants show lower PSII rates under normal growth conditions. Basal PSII thermotolerance was affected by mutations in clpB1, cpcC2, hspA, htpG and slr1674. Final PSII thermotolerance was affected by mutations in cpcC2, hik34, hspA and hypA1, suggesting that these gene products play roles in long-term thermal acclimation of PSII. Gene expression levels were compared during a time-course (up to 8 hours) of thermal acclimation (from 25C to 38C) of a wild-type strain grown under continuous illumination and bubbled with CO2 -enriched air. Up to four independent biological replicates were generated and analysed. Each array: replicate matched time-point vs. 0hr control.
2010-04-09 | E-GEOD-21133 | biostudies-arrayexpress
Project description:Global proteomic characterization of photosystem II complexes from Synechocystis 6803
| PRJNA103405 | ENA
Project description:We have investigated the response of the cyanobacterium Synechocystis sp. PCC 6803 during growth at very low O2 concentration (bubbled with 99.9% N2/0.1% CO2). Significant transcriptional changes upon low O2 incubation included up-regulation of a cluster of genes that contained psbA1 and an operon that includes a gene encoding the two-component regulatory histidine kinase, Hik31. This regulatory cluster is of particular interest, since there are virtually identical copies on both the chromosome and on plasmid pSYSX. We used a knockout mutant lacking the chromosomal copy of hik31 and studied differential transcription during the aerobic- low O2 transition in this ΔHik31 strain and the wild type. We observed two distinct responses to this transition, one Hik31 dependent, the other Hik31 independent. The Hik31 independent responses included the psbA1 induction and genes involved in chlorophyll biosynthesis. In addition, there were changes in a number of genes that may be in involved in assembling or stabilizing Photosystem II (PSII), and the hox operon and the LexA-like protein (Sll1626) were up-regulated during low O2 growth. This family of responses mostly focused on PSII and overall redox control. There was also a large set of genes that responded differently in the absence of the chromosomal Hik31. In the vast majority of these cases, Hik31 functioned as a repressor and transcription was enhanced when Hik31 was deleted. Genes in this category encoded both core and peripheral proteins for Photosystem I and PS II, the main phycobilisome proteins, chaperones, the ATP synthase cluster and virtually all of the ribosomal proteins. These findings, coupled with the fact that ΔHik31 grew better than the wild-type under low O2 conditions, suggested that Hik31 helped to regulate growth and overall cellular homeostasis. We detected changes in the transcription of other regulatory genes that may compensate for the loss of Hik31. We conclude that Hik31 regulates an important series of genes that relate to energy production and growth and that helps to determine how Synechocystis responds to changes in O2 conditions.
2010-10-28 | GSE24882 | GEO
Project description:Identification of Components Associated with Thermal Acclimation of Photosystem II in Synechocystis sp. PCC6803
| PRJNA126647 | ENA
Project description:To analyze the impact of photosynthetic redox signals, light sources with spectral qualities that preferentially excite either Photosystem I (PSI light) or Photosystem II (PSII light) were used. The light sources have been described in (Fey et al., 2005). Strong reduction and oxidation signals were induced by light shifts from PSI to PSII light (PSI-II) and the reverse light shift (PSII-I), respectivly. The acclimation responses were monitored at 0.5, 2, 8, and 48h after a light shift. Samples taken prior to changing the light quality (0h) served as control. Keywords: photosynthesis, redox regulation, light acclimation, retrograde signalling, long term response
2009-07-30 | GSE9235 | GEO
Project description:To analyze the impact of photosynthetic redox signals, light sources with spectral qualities that preferentially excite either Photosystem I (PSI light) or Photosystem II (PSII light) were used. The light sources have been described in (Wagner et al, Planta 2008). Strong reduction signals were induced by light shifts from PSI to PSII light (PSI-II). In order to find primary regulated genes the acclimation responses were monitored at 30 min and 60 min after a light shift. The control was continuous Psi light at the same time. We used stn7 (a thylakoid redox regulated kinase) to specifically block transduction of photosynthetic redox signal in order to compare “real” redox regulated with that of other light acclimation pathways. Keywords: photosynthesis, redox regulation, light acclimation, retrograde signalling, long term response
2015-03-23 | GSE42710 | GEO
Project description:Phycobilisomes capture light energy and feed into reaction centers in cyanobacteria and red algae. Their ability to capture light across a broad spectral range, distinct from those of the chlorophylls and carotenoids, expand photosynthetic solar energy transformation globally. The energy transfer from phycobilisome to reaction centers has been established for decades, however, remarkably little is known about the structural interface between the phycobilisome and the thylakoids membrane and the reaction centers. Here, we isolated a megacomplex composed of phycobilisome with its energy acceptors, i.e., photosystem I (PSI) and photosystem II (PSII). Functional analysis showed there are highly active oxygen-evolving PSII activity and O2 consumption activity from PSI in the megacomplex. Steady state fluorescence spectroscopy analysis indicated efficient excitation energy transfer from phycobilisome to both photosystems. LC-MS analysis preceded by cross-linking chemistry identified the close association of ApcE and CP43, and of ApcD and PsaA. Mass spectrometry also identified the structural proximity of ApcD and ApcE. Femto-second time resolved fluorescence spectroscopy were employed to study the kinetic energy transfer from phycobilisome to two reaction centers in the megacomplex.
2013-11-29 | PXD000545 | Pride
Project description:An increasing number of small proteins has been identified in the genomes of well-annotated model organisms including photosynthetic cyanobacteria such as Synechocystis sp. PCC 6803. A newly assigned protein comprising 37 amino acids was analyzed that is encoded upstream of the super-oxide dismutase SodB encoding gene. The initial hypothesis that this small protein might be functionally related to SodB could not be supported, instead we provide evidence that it fulfills important functions related to the organization of photosynthetic complexes. Therefore, we named it small light-induced protein of 4 kDa, SliP4. SliP4 is strongly induced under high-light-conditions and it is co-localized to photosystem I and II as well as NDH1 complexes on thylakoid membranes. Tagged SliP4 was used to purify NDH1 complexes, where it is especially associated with the subunits NdhF1 and NdhD1. Mutation of the protein-coding part in the sliP4 gene resulted in a high-light-sensitive phenotype, because the mutant was not further able to induce cyclic electron flow and state transitions under high-light conditions. Collectively our data indicate that SliP4 contributes to the association of NDH1 with the photosystem I and/or photosystem II complexes to facilitate different electron transfer modes under high light conditions.
2023-06-07 | PXD036788 | Pride
Project description:In cyanobacteria, increasing growth temperature decreases lipid unsaturation and the ratio of monomer/trimer photosystem I (PSI) complexes. In the present study we applied Fourier-transform infrared (FTIR) spectroscopy and lipidomic analysis to study the effects of PSI monomer/oligomer ratio on the physical properties and lipid composition of thylakoids. To enhance the presence of monomeric PSI, a Synechocystis sp. PCC6803/?psaL mutant strain (PsaL) was used which, unlike both trimeric and monomeric PSI-containing wild type (WT) cells, contain only the monomeric form. The protein-to-lipid ratio remained unchanged in the mutant but, due to an increase in the lipid disorder in its thylakoids, the gel to liquid-crystalline phase transition temperature (Tm) is lower than in the WT. In thylakoid membranes of the mutant, digalactosyldiacylglycerol (DGDG), the most abundant bilayer-forming lipid is accumulated, whereas those in the WT contain more monogalactosyldiacylglycerol (MGDG), the only non-bilayer-forming lipid in cyanobacteria. In PsaL cells, the unsaturation level of sulphoquinovosyldiacylglycerol (SQDG), a regulatory anionic lipid, has increased. It seems that merely a change in the oligomerization level of a membrane protein complex (PSI), and thus the altered protein-lipid interface, can affect the lipid composition and, in addition, the whole dynamics of the membrane. Singular value decomposition (SVD) analysis has shown that in PsaL thylakoidal protein-lipid interactions are less stable than in the WT, and proteins start losing their native secondary structure at much milder lipid packing perturbations. Conclusions drawn from this system should be generally applicable for protein-lipid interactions in biological membranes.
| S-EPMC6736520 | biostudies-literature