Mechanism of the light state transition in photosynthesis. II. Analysis of phosphorylated polypeptides in the red alga, Porphyridium cruentum

Biggins, John; Campbell, Christine L.; Bruce, Doug

doi:10.1016/0005-2728(84)90088-4

Cited by 78 publications

(40 citation statements)

References 31 publications

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“…State transitions in cyanobacteria involve responses to fluctuations in the quantity and quality of incident light and the redistribution of energy harvested by phycobilisomes to mainly PSI or PSII (van Thor et al, 1998). The PSI/ PSII regions identified in Figures 5A, 5B, and 7 and Supplemental Figure 10 represent a functionally flexible array of traps where small adjustments in phycobilisome-photosystem interactions, either through local conformational changes in the phycobilisome or in underlying membrane proteins (Biggins et al, 1984) or through movement of phycobilisomes on the membrane surface (Joshua and Mullineaux, 2004), alter the destination for energy harvested by the phycobilisome. Whether the PSI-only zones in Figure 1A are also visited by phycobilisomes as part of the state transition mechanism is not known.…”

Section: Discussionmentioning

confidence: 99%

Lateral Segregation of Photosystem I in Cyanobacterial Thylakoids

et al. 2017

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Photosystem I (PSI) is the dominant photosystem in cyanobacteria and it plays a pivotal role in cyanobacterial metabolism. Despite its biological importance, the native organization of PSI in cyanobacterial thylakoid membranes is poorly understood. Here, we use atomic force microscopy (AFM) to show that ordered, extensive macromolecular arrays of PSI complexes are present in thylakoids from Thermosynechococcus elongatus, Synechococcus sp PCC 7002, and Synechocystis sp PCC 6803. Hyperspectral confocal fluorescence microscopy and three-dimensional structured illumination microscopy of Synechocystis sp PCC 6803 cells visualize PSI domains within the context of the complete thylakoid system. Crystallographic and AFM data were used to build a structural model of a membrane landscape comprising 96 PSI trimers and 27,648 chlorophyll a molecules. Rather than facilitating intertrimer energy transfer, the close associations between PSI primarily maximize packing efficiency; short-range interactions with Complex I and cytochrome b 6 f are excluded from these regions of the membrane, so PSI turnover is sustained by long-distance diffusion of the electron donors at the membrane surface. Elsewhere, PSI-photosystem II contact zones provide sites for docking phycobilisomes and the formation of megacomplexes. PSI-enriched domains in cyanobacteria might foreshadow the partitioning of PSI into stromal lamellae in plants, similarly sustained by long-distance diffusion of electron carriers.

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Section: Discussionmentioning

confidence: 99%

Lateral Segregation of Photosystem I in Cyanobacterial Thylakoids

et al. 2017

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“…However, a high NPQ appeared under this controlling condition (Figure 2), suggesting that a component of NPQ, independent from state transition or photo-inhibition, existed in the PSII complex, and was a fast component under high light conditions. GA has commonly been used to stabilize the PPPTM conformation such as PBS conformation [15,28], and GA also can stabilize all kinds of PPPTM including OCP. NPQ significantly increased at room temperature (25°C) in the presence of GA (Figure 2).…”

Section: Discussionmentioning

confidence: 99%

“…The maximum relative electron transport rate (rETR max ) plotted against different temperatures (30,28,26,24,22,20,18,16,14,12,10, and 8°C) showed a discontinuity point caused by change in the physical phase of the thylakoid membrane. Also, the maximum photochemical efficiency of PSII (F v /F m ) was plotted against decreasing temperature, where the temperature of the highest F v /F m value was used to suggest the phase-transition temperature of the thylakoid membrane.…”

Section: Phase-transition Temperature Of the Thylakoid Membranementioning

confidence: 99%

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Conformational changes in photosynthetic pigment proteins on thylakoid membranes can lead to fast non-photochemical quenching in cyanobacteria

Wang

Dong

2012

Sci. China Life Sci.

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A high non-photochemical quenching (NPQ) appeared below the phase transition temperature when Microcystis aeruginosa PCC7806 cells were exposed to saturated light for a short time. This suggested that a component of NPQ, independent from state transition or photo-inhibition, had been generated in the PSII complex; this was a fast component responding to high intensity light. Glutaraldehyde (GA), commonly used to stabilize membrane protein conformations, resulted in more energy transfer to PSII reaction centers, affecting the energy absorption and dissipation process rather than the transfer process of phycobilisome (PBS). In comparison experiments with and without GA, the rapid light curves (RLCs) and fluorescence induction dynamics of the fast phase showed that excess excitation energy was dissipated by conformational change in the photosynthetic pigment proteins on the thylakoid membrane (PPPTM). Based on deconvolution of NPQ relaxation kinetics, we concluded that the fast quenching component (NPQ f ) was closely related to PPPTM conformational change, as it accounted for as much as 39.42% of the total NPQ. We hypothesize therefore, that NPQ f induced by PPPTM conformation is an important adaptation mechanism for Microcystis blooms under high-intensity light during summer and autumn. In various cyanobacteria, harvested light energy absorbed by phycobilisomes (PBS) is transferred from L CM to the chlorophylls of photosystem II (PSII) and photosystem I (PSI) [1,2]. Some excitons are formed in the reaction center (RC) and are then deactivated through three pathways: photochemical reaction, fluorescence, and thermal dissipation or non-photochemical quenching (NPQ) [3,4]. NPQ is an indispensable pathway of deactivation and plays an important role in protecting PSII from photo-inhibition or photo-damage when exposed to stress conditions [5,6]. Rapid relaxation of NPQ in darkness suggests that algae have a strong vitality and adaptability to high intensity light. NPQ can be deconvoluted into three components based on the different relaxation times in dark periods after exposure to high intensity light [7][8][9]. These three components of NPQ were found to be (i) a fast quenching component (NPQ f ), which refers to the ΔpH-dependent process or high-energy state (qE); (ii) a medium quenching component (NPQ m ), related to the quenching of state transition process (qT); and (iii), a low quenching component (qI), resulting from photo-inhibition of photosynthesis. In cyanobacteria there is no qE dependence on a trans-thylakoid proton gradient [10], although this is the predominant component of NPQ in higher plants [11]. Since

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“…the spill-over, changes as a function of the state transition. Thus the spill-over mechanism seems to be common for state transitions both in PBS-containing alga and in green alga (see above), although it probably does not involve phosphorylation of a Chl-protein in the former (Biggins et al, 1984).…”

Section: Energy Transfer In Phycobiliprotein Containing Algaementioning

confidence: 99%