Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O<sub>2</sub>-Evolving System in Flash-Grown Wheat Leaves

Ono, Tetsuya; Kajikawa, H.; Inoue, Yorinao

doi:10.1104/pp.80.1.85

Cited by 39 publications

(13 citation statements)

References 23 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As postulated for the activating mechanism (8,21,25), those protonations may occur in the cleft holding the Mn cluster. Such a concept would be consistent with the observation that the presence of functional Mn is a prerequisite for the binding of the two small extrinsic polypeptides (3,32,34 The different effectivenesses of Cl-and substituting monovalent anions can be explained by differences of size (2) and hydration energies, which would affect their access to the binding sites, and the binding strength (37). Furthermore, studies of the response of the water oxidizing mechanism to F (13) and investigations of Cl-binding with 35C1-NMR (10) have suggested that the population of binding sites is heterogeneous.…”

Section: Discussionsupporting

confidence: 68%

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Homann¹

1988

Plant Physiol.

View full text Add to dashboard Cite

To further our understanding of the role of Cl-and certain other monovalent anions in the oxygen evolving photosystem II of chloroplasts, dissociating and stabilizing anion effects on the extrinsic 17 and 23 kilodalton polypeptides of the photosynthetic water oxidizing complex were investigated. It was found that (a) the dissociation of the two polypeptides in Cl-free media of pH -7 was enhanced by millimolar concentrations of the divalent anion S042-and also by divalent cations like Mg2" and Ca2"; (b) the dissociation was opposed by relatively low concentrations of monovalent anions with an order of effectiveness Cl-= Br-> N03-> F > C104-; (c) at molar concentrations, S042-stabilized the binding of the 23 kilodalton polypeptide, while Cl-and Br-became dissociating agents, in agreement with studies by Blough and Sauer (1984 Biochim Biophys Acta 767: 377-381); (d) the binding of the polypeptides was strengthened at room temperature relative to 0°C, indicating an involvement of hydrophobic forces. It is suggested that a specific binding of Cl-, or certain substitutes, organizes the protein surfaces and/or the adjacent water layers in the water oxidizing complex in a way that not only stabilizes its assembly, but is essential for the catalytic mechanism as well. Binding of, or charge screening by, divalent ions interferes with this process. At high salt concentrations, all these effects are overridden by "lyotropic" actions of the solutes that affect the integrity of the water oxidizing protein complex by stabilizing or disrupting critical hydrophobic domains.Removal of Cl-from PSII of chloroplast thylakoids causes an aberration and interruption of the normal progress of charge accumulation in and perhaps around the Mn-cluster ofthe water oxidizing complex (for reviews, see Refs. 15, 17, and 21). However, the exact function of Cl-is not understood. Sandusky and Yocum (33) have proposed that an essential step in the mechanism of water oxidation is a ligation of Cl-to the Mn-cluster itself. This concept was developed on the basis of their finding that Cl-, in a competitive fashion, protected the water oxidizing mechanism from the inhibitory action of NH3 and various amines, the action of which was attributed to a binding to the oxidant storing Mn-complex. Taking an alternative view, Govindjee's group (8, 17) and we (19,21) have proposed various mechanistic versions for a role of protein-bound Cl-in the deprotonation events accompanying water oxidation. Such an indirect participation of the anion in the catalytic process was postulated because of precedents in other enzyme systems (8,14) and to account for the reported need of more than one Cl-per ' Supported by grant DMB 8304416 from the National Science Foundation.water oxidizing complex (35), the unique pH dependence of Clbinding (21), the complex pattern of 35Cl-NMR line broadening (2, 10), and the ability of other monovalent anions such as NO3 to serve as rather efficient substitutes for 18,24,28).The Cl-relations of PSII are known to be greatly influenc...

show abstract

Section: Discussionsupporting

confidence: 68%

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Homann¹

1988

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Conversion of etioplasts to chloroplasts occurs when the shoot emerges from the soil and is exposed to light. Coordination of several phytochrome-mediated events is required for this conversion (Hendricks and Van der Woude, 1993) and includes transformation of prolamellar bodies into thylakoids (Gunning and Steer, 1975), photoreduction of protochlorophyllide to chlorophyllide and subsequent addition of the polyisoprene-phytyl moiety to yield chlorophyll (Klein, Katz, and Neeman, 1977;Castelfranco and Beale, 1983), and synthesis of the four major protein complexes of the thylakoid membranes: photosystem (PS) II, PS I, cytochrome-B 6 f complex, and ATP synthase (Ono, Kajikawa, and Inoue, 1986;Mullet, 1988).…”

mentioning

confidence: 99%

Development of photosystem‐II activity during irradiance of etiolated Helianthus (Asteraceae) seedlings

Lebkuecher

Haldeman

Harris

et al. 1999

American J of Botany

View full text Add to dashboard Cite

Light-induced development of photosystem (PS)-II activity was followed during irradiance of etiolated Helianthus annuus (sunflower) cotyledons using chlorophyll a fluorescence. Cotyledons from seedlings grown in continuous darkness for 6 d were exposed to 100 μmol photons·m(-2)·s(-1) for time periods of 1, 3, 6, and 12 h. Associated with increased time of irradiance exposure were significant: (1) increases in concentration of PS II, (2) increases in quantum efficiency of PS II, (3) decreases in the ratio of PS-II quinone(B) (Q(B))-nonreducing centers to total PS-II centers (PS-II Q(B)-nonreducing centers + PS-II Q(B)-reducing centers), and (4) decreases in the ratio of slow PS-II Q(B)-reducing centers to total PS-II Q(B)-reducing centers (fast PS-II Q(B)-reducing centers + slow PS-II Q(B)-reducing centers). The results support the hypotheses that development of PS II involves assembly of complexes which initially cannot reduce Q(B) and that heterogeneous aspects of PS-II pools during chloroplast maturation may represent different developmental states.

show abstract

“…Abundances ofthe three proteins, relative to the 47 kD Chl-carrying protein, in PSII membranes were comparable to those in the thylakoid membranes. In contrast to the thylakoids, about (17). The absence of the two proteins in PSII membranes from dark, chillingtreated cucumber leaves cannot be ascribed to proteolytic digestion of the proteins during the treatment because the two proteins were still present in the thylakoid membranes isolated from treated leaves.…”

Section: Resultsmentioning

confidence: 98%

“…The Mn atoms are considered to be located on the Dl and D2 proteins of the PSII reaction center complex (13,19). Three extrinsic proteins of 33, 23, and 17 kD, which are associated with the lumenal side ofthe thylakoid membranes, are also essential for oxygen evolution. The 33-kD protein is needed to maintain the functional conformation of the Mn cluster, whereas the extrinsic 23-and 17-kD proteins have regulatory roles in oxygen evolution (8).…”

mentioning

confidence: 99%

Cause for Dark, Chilling-Induced Inactivation of Photosynthetic Oxygen-Evolving System in Cucumber Leaves

Shen¹,

Terashima²,

Katoh³

1990

Plant Physiol.

View full text Add to dashboard Cite

Effects on oxygen evolution of the storage of detached cucumber (Cucumis sativus) leaves at 0°C in the dark were investigated with thylakoids and oxygen-evolving photosystem 11 membranes isolated from stored leaves. The cold and dark treatment of leaves selectively inactivated electron transport on the oxidizing side of photosystem I. Photosystem II membranes isolated from treated leaves were largely depleted of two proteins of 20 and 14 kilodaltons, which correspond to the extrinsic 23-and 17-kilodalton proteins of spinach functioning in oxygen evolution. The manganese content of photosystem 11 membranes was also markedly reduced by the treatment. Thus, the inactivation of oxygen evolution induced by the dark, chilling treatment is ascribed to solubilization of the 20-and 14-kilodalton proteins and extraction of manganese.Photosynthetic oxygen evolution takes place in a discrete multiprotein complex of thylakoid membranes, which carries Chl a, carotenoids, and various reaction components or cofactors. Among others, four Mn atoms bound to the complex play a central role in cleavage of water molecules, which leads to the production of molecular oxygen. The Mn atoms are considered to be located on the Dl and D2 proteins of the PSII reaction center complex (13,19). Three extrinsic proteins of 33, 23, and 17 kD, which are associated with the lumenal side ofthe thylakoid membranes, are also essential for oxygen evolution. The 33-kD protein is needed to maintain the functional conformation of the Mn cluster, whereas the extrinsic 23-and 17-kD proteins have regulatory roles in oxygen evolution (8). Removal of the two proteins from inside-out thylakoid vesicles or PSII membranes, with a high concentration of NaCl, strongly suppresses oxygen evolution (1), but the lost activity is largely restored by addition of Ca2' and Cl- (6,14,16 cluster becomes unstable in the presence of exogenous reductants (7).Treatment of cucumber (Cucumis sativus L.) leaves at 0°C in the dark is known to inactivate selectively the oxygenevolving system because thylakoid membranes isolated from treated leaves are capable of photoreducing DCIP3 only in the presence of exogenous electron donors, such as DPC (4,10,20). Fluorescence induction determined at 77 K and 25°C also demonstrated that the chilling-sensitive site is not the PSII reaction center but electron transport on the oxidizing side of the reaction center (4, 20). The mechanism of the inactivation, however, still remains unclear. Kaniuga et al. (I 1) have shown that the Mn content of isolated chloroplasts decreased by 40 to 50% upon the cold and dark storage of tomato leaves, concomitant with an almost complete inactivation of the Hill reaction, and the changes were largely reversed by illumination of the treated leaves. The results suggest that loss of the Mn is the cause of inactivation. However, Mn atoms present in chloroplasts are heterogeneous in terms of both function and binding stability and there is a significant amount of Mn not related to photosynthetic oxygen evoluti...

show abstract

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Cited by 39 publications

References 23 publications

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Development of photosystem‐II activity during irradiance of etiolated Helianthus (Asteraceae) seedlings

Cause for Dark, Chilling-Induced Inactivation of Photosynthetic Oxygen-Evolving System in Cucumber Leaves

Contact Info

Product

Resources

About

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O2-Evolving System in Flash-Grown Wheat Leaves

Cited by 39 publications

References 23 publications

Structural Effects of Cl− and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Structural Effects of Cl− and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Development of photosystem‐II activity during irradiance of etiolated Helianthus (Asteraceae) seedlings

Cause for Dark, Chilling-Induced Inactivation of Photosynthetic Oxygen-Evolving System in Cucumber Leaves

Contact Info

Product

Resources

About

Changes in Protein Composition and Mn Abundance in Photosystem II Particles on Photoactivation of the Latent O₂-Evolving System in Flash-Grown Wheat Leaves

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II

Structural Effects of Cl⁻ and Other Anions on the Water Oxidizing Complex of Chloroplast Photosystem II