Granum revisited. A three-dimensional model ? where things fall into place

Mustárdy, László; Garab, Győző

doi:10.1016/s1360-1385(03)00015-3

Cited by 180 publications

(161 citation statements)

References 45 publications

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“…This internal membrane system is laterally differentiated into densely stacked domains (grana) and unstacked regions (stroma lamellae) (Mustárdy and Garab, 2003;Shimoni et al, 2005;Mustárdy et al, 2008;Austin and Staehelin, 2011;Kouril et al, 2011). The thylakoid membrane is a highly dynamic system capable of adapting to changing environmental conditions.…”

Section: Introductionmentioning

confidence: 99%

“…As mentioned above, the thylakoid membranes in plant chloroplasts are involved in the formation of unique threedimensional structures characterized by the membrane stacks called grana, connected by the thylakoid membrane of the stroma region (Mustárdy and Garab, 2003;Goral et al, 2012). Precise microscopy studies have largely elucidated the architecture of thylakoid membranes.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Architecture of Plant Thylakoids under Physiological and Light Stress Conditions: A Study of Lipid-Light-Harvesting Complex II Model Membranes

et al. 2013

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In this study, we analyzed multibilayer lipid-protein membranes composed of the photosynthetic light-harvesting complex II (LHCII; isolated from spinach [Spinacia oleracea]) and the plant lipids monogalcatosyldiacylglycerol and digalactosyldiacylglycerol. Two types of pigment-protein complexes were analyzed: those isolated from dark-adapted leaves (LHCII) and those from leaves preilluminated with high-intensity light (LHCII-HL). The LHCII-HL complexes were found to be partially phosphorylated and contained zeaxanthin. The results of the x-ray diffraction, infrared imaging microscopy, confocal laser scanning microscopy, and transmission electron microscopy revealed that lipid-LHCII membranes assemble into planar multibilayers, in contrast with the lipid-LHCII-HL membranes, which form less ordered structures. In both systems, the protein formed supramolecular structures. In the case of LHCII-HL, these structures spanned the multibilayer membranes and were perpendicular to the membrane plane, whereas in LHCII, the structures were lamellar and within the plane of the membranes. Lamellar aggregates of LHCII-HL have been shown, by fluorescence lifetime imaging microscopy, to be particularly active in excitation energy quenching. Both types of structures were stabilized by intermolecular hydrogen bonds. We conclude that the formation of trans-layer, rivet-like structures of LHCII is an important determinant underlying the spontaneous formation and stabilization of the thylakoid grana structures, since the lamellar aggregates are well suited to dissipate excess energy upon overexcitation.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Architecture of Plant Thylakoids under Physiological and Light Stress Conditions: A Study of Lipid-Light-Harvesting Complex II Model Membranes

et al. 2013

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“…The thylakoid membrane in plants is divided into grana, which are composed of stacks of membrane disks, and stroma lamellae, which connect the various grana in the choroplast (Mustardy and Garab 2003;Shimoni et al 2005;Mustardy et al 2008;Daum et al 2010;Kouril et al 2011). PSII is located in the grana (Andersson and Anderson 1980) whereas PSI is mainly present in the stroma lamellae (together with the ATP synthase).…”

Section: Introductionmentioning

confidence: 99%

Light-Harvesting in Photosystem II

Amerongen¹,

Dekker

2003

Light-Harvesting Antennas in Photosynthesis

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Water oxidation in photosynthesis takes place in photosystem II (PSII). This photosystem is built around a reaction center (RC) where sunlight-induced charge separation occurs. This RC consists of various polypeptides that bind only a few chromophores or pigments, next to several other cofactors. It can handle far more photons than the ones absorbed by its own pigments and therefore, additional excitations are provided by the surrounding light-harvesting complexes or antennae. The RC is located in the PSII core that also contains the inner light-harvesting complexes CP43 and CP47, harboring 13 and 16 chlorophyll pigments, respectively. The core is surrounded by outer light-harvesting complexes (Lhcs), together forming the so-called supercomplexes, at least in plants. These PSII supercomplexes are complemented by some ''extra'' Lhcs, but their exact location in the thylakoid membrane is unknown. The whole system consists of many subunits and appears to be modular, i.e., both its composition and organization depend on environmental conditions, especially on the quality and intensity of the light. In this review, we will provide a short overview of the relation between the structure and organization of pigment-protein complexes in PSII, ranging from individual complexes to entire membranes and experimental and theoretical results on excitation energy transfer and charge separation. It will become clear that time-resolved fluorescence data can provide invaluable information about the organization and functioning of thylakoid membranes. At the end, an overview will be given of unanswered questions that should be addressed in the near future.

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“…Under electron microscopy, cylindrical grana consisting of 10 -20 layers of thylakoids have been observed. They have a diameter of 300 -600 nm and are interconnected by lamellae of several hundred nm in length (1,2). The structure of grana in the chloroplasts of higher plants is well known, but the precise role of grana is incompletely understood.…”

mentioning

confidence: 99%

“…It comprises Ͼ25 protein subunits and other low molecular weight cofactors, including chlorophylls, carotenoids, plastoquinones, and manganeses. In the chloroplasts of higher plants, PSII complexes and the associated light-harvesting antenna complex LHCII are not present throughout the thylakoid membranes but are abundant in the grana (2,14). A densely packed array of PSII complexes in the grana was visualized by electron microscopy (8,15).…”

mentioning

confidence: 99%

Quality Control of Photosystem II

Khatoon

Inagawa

Pospı́šil

et al. 2009

Journal of Biological Chemistry

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Photosystem II is vulnerable to light damage. The reaction center-binding D1 protein is impaired during excessive illumination and is degraded and removed from photosystem II. Using isolated spinach thylakoids, we investigated the relationship between light-induced unstacking of thylakoids and damage to the D1 protein. Under light stress, thylakoids were expected to become unstacked so that the photodamaged photosystem II complexes in the grana and the proteases could move on the thylakoids for repair. Excessive light induced irreversible unstacking of thylakoids. By comparing the effects of light stress on stacked and unstacked thylakoids, photoinhibition of photosystem II was found to be more prominent in stacked thylakoids than in unstacked thylakoids. In accordance with this finding, EPR spin trapping measurements demonstrated higher production of hydroxyl radicals in stacked thylakoids than in unstacked thylakoids. We propose that unstacking of thylakoids has a crucial role in avoiding further damage to the D1 protein and facilitating degradation of the photodamaged D1 protein under light stress.In the chloroplasts of higher plants and green algae, thylakoid membranes are closely associated and stack to form grana. Under electron microscopy, cylindrical grana consisting of 10 -20 layers of thylakoids have been observed. They have a diameter of 300 -600 nm and are interconnected by lamellae of several hundred nm in length (1, 2). The structure of grana in the chloroplasts of higher plants is well known, but the precise role of grana is incompletely understood. Their possible functions in primary photochemical reactions and subsequent events have been discussed extensively (3-9). Photosystem I (PSI) 3 and II (PSII) complexes are segregated from each other in thylakoids, showing lateral heterogeneity in their distribution. The PSII complex is a multisubunit pigment-protein complex responsible for the photochemical oxidation of water and reduction of plastoquinone (8, 10 -13). It comprises Ͼ25 protein subunits and other low molecular weight cofactors, including chlorophylls, carotenoids, plastoquinones, and manganeses. In the chloroplasts of higher plants, PSII complexes and the associated light-harvesting antenna complex LHCII are not present throughout the thylakoid membranes but are abundant in the grana (2, 14). A densely packed array of PSII complexes in the grana was visualized by electron microscopy (8, 15). Grana formation is more prominent in shade leaves (or shade plants) than in sun leaves (or sun plants), so it has been suggested that enrichment of the PSII⅐LHCII complex in grana is a strategy of plants to collect excitation energy by PSII under weak light (16). The grana structure probably provides an organized environment for PSII. PSI and ATP synthase are located exclusively in the stroma-exposed thylakoids, including the stroma thylakoids, grana end membranes, and grana margins, because these complexes protrude into the stroma. Cytochrome b 6 /f complexes without this protrusion are present unif...

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Granum revisited. A three-dimensional model ? where things fall into place

Cited by 180 publications

References 45 publications

Molecular Architecture of Plant Thylakoids under Physiological and Light Stress Conditions: A Study of Lipid-Light-Harvesting Complex II Model Membranes

Molecular Architecture of Plant Thylakoids under Physiological and Light Stress Conditions: A Study of Lipid-Light-Harvesting Complex II Model Membranes

Light-Harvesting in Photosystem II

Quality Control of Photosystem II

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