COOH-terminal processing of polypeptide D1 of the photosystem II reaction center of Scenedesmus obliquus is necessary for the assembly of the oxygen-evolving complex.

Diner, Bruce A.; Ries, D F; Cohen, Bennett N.; Metz, James G.

doi:10.1016/s0021-9258(18)68403-0

Cited by 163 publications

(23 citation statements)

References 51 publications

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“…5 B, this protein is also found in fractions corresponding to the top region of the gradient (lanes 5-8), where D1, as shown in B of Fig. 3 (lanes [15][16][17][18] is not present. Immunodetection of CP43 in this region of the gradient was not observed in the dark control thylakoids (Fig.…”

Section: Light-induced Dissociation Of Psl and Psiimentioning

confidence: 71%

“…Encoded by the plastidial psbA gene (13), the protein is translated on 70S ribosomes on the stroma-exposed surface of the thylakoid membrane (23), into which the protein is inserted in the form of a precursor containing an extra se-quence of 9-10 amino acid residues at the COOH-terminus (33,46). A number of posttranslational modifications such as COOH-terminal proteolytic processing to its definitive molecular size (18,33), palmitoylation (34), and phosphorylation (37,53) are involved in the maturation of the protein. As a result, the protein migrates from the stroma-exposed membranes to the grana compartment, where it is found assembled with other core proteins to form a functional PSII center.…”

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confidence: 99%

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Structural changes and lateral redistribution of photosystem II during donor side photoinhibition of thylakoids.

Barbato

Friso

Rigoni

et al. 1992

The Journal of Cell Biology

147

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Abstract. The structural and topological stability of thylakoid components under photoinhibitory conditions (4,500/zE.m-2.s -t white light) was studied on Mn depleted thylakoids isolated from spinach leaves. After various exposures to photoinhibitory light, the chlorophyll-protein complexes of both photosystems I and II were separated by sucrose gradient centrifugation and analysed by Western blotting, using a set of polyclonals raised against various apoproteins of the photosynthetic apparatus. A series of events occurring during donor side photoinhibition are described for photosystem II, including: (a) lowering of the oligomerization state of the photosystem H core; (b) cleavage of 32-kD protein D1 at specific sites; (c) dissociation of chlorophyll-protein CP43 from the photosystem II core; and (d) migration of damaged photosystem II components from the grana to the stroma lamellae. A tentative scheme for the succession of these events is illustrated. Some effects of photoinhibition on photosystem I are also reported involving dissociation of antenna chlorophyll-proteins LHCI from the photosystem I reaction center.I NHIBITION of photosynthesis by light, a phenomenon referred to as photoinhibition (44), is a common feature of all oxygenic organisms. At the molecular level, one main target of photoinhibition is photosystem II (PSII), ~ whose electron transport activity is severely impaired by excess illumination. Two different photoinhibition mechanisms have been suggested to be operative under different experimental conditions: an acceptor side mechanism involving over-reduction of the plastoquinone acceptors which depends on the presence of oxygen (32, 50, 52), and a donor side mechanism, involving accumulation of the strongly oxidant species Tyrz + and/or P6s0 + and independent of the presence of oxygen (27,54). Irrespective of the particular mechanism for electron transport damage, photoinhibition is accompanied by an increased rate of degradation of the reaction center 7,24,26,51). In the light D1 turns over at a rate higher than any other polypeptide of the thylakoid membrane and this increases with light intensity (35). After this observation the loss of PSII activity under photoinhibitory conditions has been attributed to accelerated degradation, exceeding the biosynthetic rate of Dl-protein (40). According to this hypothesis, recovery from photoinhibition depends on the substitution of damaged Dl-protein with the newly synthesized one within the PSH structure (30). Biosynthesis of the 32-kD D1 polypeptide has been widely studied. Encoded by the plastidial psbA gene (13), the protein is translated on 70S ribosomes on the stroma-exposed surface of the thylakoid membrane (23), into which the protein is inserted in the form of a precursor containing an extra se-1. Abbreviations used in this paper: CP, chlorophyll protein; LHC, light harvesting complex; OEE, oxygen evolving enhancer; PS, photosystem. quence of 9-10 amino acid residues at the COOH-terminus (33,46). A number of posttranslational modifications...

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Section: Light-induced Dissociation Of Psl and Psiimentioning

confidence: 71%

mentioning

confidence: 99%

Structural changes and lateral redistribution of photosystem II during donor side photoinhibition of thylakoids.

Barbato

Friso

Rigoni

et al. 1992

The Journal of Cell Biology

147

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“…We observed previously that such antenna and to the LHC is symbolized by diamonds. Interaction sites between OEE subunits and the PSH core are drawn taking into account the various reports on OEE binding sites (5,16,17,26). Proper OEE binding is not a prerequisite for PSH core (as well as for PSII unit) assembly and is therefore drawn in dashed lines.…”

Section: Discussionmentioning

confidence: 99%

“…3 A. Most of the t~ and B subunits of the ATP synthase were found at the bottom part of the gradient (lane 5) whereas cytochromefand cytochrome b6 were located in the middle of the gradient (lanes [15][16][17][18][19].…”

Section: Assembly Of the Psii Core Subunits: A Ps/di/d2/l8 Stepmentioning

confidence: 99%

Posttranslational events leading to the assembly of photosystem II protein complex: a study using photosynthesis mutants from Chlamydomonas reinhardtii.

Vitry

Olive

Drapier

et al. 1989

The Journal of Cell Biology

247

179

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Abstract. We studied the assembly of photosystem II (PSII) in several mutants from Chlamydomonas reinhardtii which were unable to synthesize either one PSII core subunit (P6 [43 kD], D1, or D2) or one oxygen-evolving enhancer (OEE1 or OEE2) subunit. Synthesis of the PSII subunits was analyzed on electrophoretograms of cells pulse labeled with [14C]acetate. Their accumulation in thylakoid membranes was studied on immunoblots, their chlorophyll-binding ability on nondenaturating gels, their assembly by detergent fractionation, their stability by pulse-chase experiments and determination of in vitro protease sensitivity, and their localization by immunocytochemistry.In Chlamydomonas, the PSII core subunits P5 (47 kD), D1, and D2 are synthesized in a concerted manner while P6 synthesis is independent. P5 and P6 accumulate independently of each other in the stacked membranes. They bind chlorophyll soon after, or concomitantly with, their synthesis and independently of the presence of the other PSII subunits. Resistance to degradation increases step by step: beginning with assembly of P5, D1, and D2, then with binding of P6, and, finally, with binding of the OEE subunits on two independent high affinity sites (one for OEE1 and another for OEE2 to which OEE3 binds). In the absence of PSII cores, the OEE subunits accumulate independently in the thylakoid lumen and bind loosely to the membranes; OEE1 was found on stacked membranes, but OEE2 was found on either stacked or unstacked membranes depending on whether or not P6 was synthesized.p HOTOSYSTEM IX (PSII) ~ is a major protein complex of the photosynthetic apparatus in oxygen-evolving species. Light-harvesting chlorophyll-protein complexes (LHCs) transfer excitons to PSII cores where primary photochemistry occurs. PSII complexes (PSII cores with oxygen-evolving enhancer [OEE] subunits) are able to carry out the oxidation of water.The PSII core comprises five main intrinsic chloroplastencoded subunits P5, P6, D1, D2, and cytochrome b559 (59). Their molecular masses vary slightly from one species to another. Two subunits of 4%50 and 43-47 kD, called P5 and P6 in Chlamydomonas reinhardtii or by their molecular mass in higher plants (respectively encoded by psbB and psbC genes), bind most of the PSII core chlorophylls (58) and form the core antenna (9, 44). The chlorophyll-P5 and chlorophyll-P6 complexes-called, respectively, CPIII and CPIV in C. reinhardtii or CP47 and CP43 in higher plantscan be separated by electrophoresis at 4°C (13, 21). D1 and D2 of 32-35 kD (encoded, respectively, by psbA and psbD genes [18,48,64]) cooperate in the binding of the primary 1. Abbreviations used in this paper: LHC, light-harvesting complex; OEE, oxygen-evolving enhancer; PSII, photosystem II; WT, wild type. reactants (44) and show sequence homologies with the subunits L and M of the reaction center from purple bacteria (39, 53). Three extrinsic polypeptides encoded by nuclear genes (12, 60) are involved in oxygen evolution; OEE1 (29-33 kD) stabilizes the association of manganese ions ...

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“…Coordination of the processing of the D1 C-terminal extension with the assembly of CP43 might be important for 'safe' ligation of the Mn cluster and subsequent photoactivation of the OEC, which have been shown to be extremely susceptible to inactivation by light (Rova et al 1998). Finally, the removal of the C-terminal extension makes possible the restoration of the water-splitting activity of PSII (Diner et al 1988;Bowyer et al 1992). It is noteworthy that the OEC proteins, released from PSII during its repair cycle, do not undergo rapid turnover and are thus not targeted for degradation when free in the lumen.…”

Section: (I) Psba Transcripts and Translation Initiationmentioning

confidence: 99%

Biogenesis, assembly and turnover of photosystem II units

Baena-González

Aro

2002

Phil. Trans. R. Soc. Lond. B

204

148

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Assembly of photosystem II, a multiprotein complex embedded in the thylakoid membrane, requires stoichiometric production of over 20 protein subunits. Since part of the protein subunits are encoded in the chloroplast genome and part in the nucleus, a signalling network operates between the two genetic compartments in order to prevent wasteful production of proteins. Coordinated synthesis of proteins also takes place among the chloroplast-encoded subunits, thus establishing a hierarchy in the protein components that allows a stepwise building of the complex. In addition to this dependence on assembly partners, other factors such as the developmental stage of the plastid and various photosynthesis-related parameters exert a strict control on the accumulation, membrane targeting and assembly of the PSII subunits. Here, we briefly review recent results on this field obtained with three major approaches: biogenesis of photosystem II during the development of chloroplasts from etioplasts, use of photosystem II-specific mutants and photosystem II turnover during its repair cycle.

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COOH-terminal processing of polypeptide D1 of the photosystem II reaction center of Scenedesmus obliquus is necessary for the assembly of the oxygen-evolving complex.

Cited by 163 publications

References 51 publications

Structural changes and lateral redistribution of photosystem II during donor side photoinhibition of thylakoids.

Structural changes and lateral redistribution of photosystem II during donor side photoinhibition of thylakoids.

Posttranslational events leading to the assembly of photosystem II protein complex: a study using photosynthesis mutants from Chlamydomonas reinhardtii.

Biogenesis, assembly and turnover of photosystem II units

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