Form and Function of Cytochrome b-559

Whitmarsh, John; Pakrasi, Himadri B.

doi:10.1007/0-306-48127-8_13

Cited by 40 publications

(46 citation statements)

References 103 publications

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“…On a protein basis, about 5-8% of the total cellular contents of D1, D2, and MSP were present in the plasma membrane fraction. In contrast, 15-20% of the two subunits of cytochrome b559, a protein that has been postulated to be a nucleation center during the assembly PSII (24,25), were found in this membrane sample. However, the chlorophyll binding proteins CP47 and CP43, comprising the inner light-harvesting antenna of PSII, were not detected in the plasma membrane preparation and found exclusively in the thylakoids.…”

Section: Resultsmentioning

confidence: 57%

The initial steps of biogenesis of cyanobacterial photosystems occur in plasma membranes

Zak

Norling

Maitra

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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177

160

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During oxygenic photosynthesis in cyanobacteria and chloroplasts of plants and eukaryotic algae, conversion of light energy to biologically useful chemical energy occurs in the specialized thylakoid membranes. Light-induced charge separation at the reaction centers of photosystems I and II, two multisubunit pigment-protein complexes in the thylakoid membranes, energetically drive sequential photosynthetic electron transfer reactions in this membrane system. In general, in the prokaryotic cyanobacterial cells, the thylakoid membrane is distinctly different from the plasma membrane. We have recently developed a two-dimensional separation procedure to purify thylakoid and plasma membranes from the genetically widely studied cyanobacterium Synechocystis sp. PCC 6803. Immunoblotting analysis demonstrated that the purified plasma membrane contained a number of protein components closely associated with the reaction centers of both photosystems. Moreover, these proteins were assembled in the plasma membrane as chlorophyll-containing multiprotein complexes, as evidenced from nondenaturing green gel and low-temperature fluorescence spectroscopy data. Furthermore, electron paramagnetic resonance spectroscopic analysis showed that in the partially assembled photosystem I core complex in the plasma membrane, the P700 reaction center was capable of undergoing light-induced charge separation. Based on these data, we propose that the plasma membrane, and not the thylakoid membrane, is the site for a number of the early steps of biogenesis of the photosynthetic reaction center complexes in these cyanobacterial cells.

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Section: Resultsmentioning

confidence: 57%

The initial steps of biogenesis of cyanobacterial photosystems occur in plasma membranes

Zak

Norling

Maitra

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

177

160

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“…These included the core proteins, D1 and D2 for PSII and PsaA and PsaB for PSI, which are generally accepted as being essential (Nechushtai et al, 1996;Satoh, 1996). Chl-binding proteins (CP-43 and CP-47) are also typically found associated with the PSII complex (Bricker and Ghanotakis, 1996), as well as cyt b 559 (Whitmarsh and Pakrasi, 1996). Antibodies to CP-43 and heme staining for cyt b 559 revealed that both were present at relatively high levels throughout the entire symbiotic association.…”

Section: Discussionmentioning

confidence: 99%

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

et al. 2000

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Early in its life cycle, the marine mollusc Elysia chlorotica Gould forms an intracellular endosymbiotic association with chloroplasts of the chromophytic alga Vaucheria litorea C. Agardh. As a result, the dark green sea slug can be sustained in culture solely by photoautotrophic CO 2 fixation for at least 9 months if provided with only light and a source of CO 2 . Here we demonstrate that the sea slug symbiont chloroplasts maintain photosynthetic oxygen evolution and electron transport activity through photosystems I and II for several months in the absence of any external algal food supply. This activity is correlated to the maintenance of functional levels of chloroplast-encoded photosystem proteins, due in part at least to de novo protein synthesis of chloroplast proteins in the sea slug. Levels of at least one putative algal nuclear encoded protein, a light-harvesting complex protein homolog, were also maintained throughout the 9-month culture period. The chloroplast genome of V. litorea was found to be 119.1 kb, similar to that of other chromophytic algae. Southern analysis and polymerase chain reaction did not detect an algal nuclear genome in the slug, in agreement with earlier microscopic observations. Therefore, the maintenance of photosynthetic activity in the captured chloroplasts is regulated solely by the algal chloroplast and animal nuclear genomes.

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“…Cytochrome b559 is a heme protein and an essential component of all photosystem II reaction centers. If the membrane lacks cytochrome, a stable PS II reaction center cannot be formed [69]. It was also found that copper ions oxidized directly the low potential form cyt b559 at low concentrations (1-10 µM) and the high potential form at higher concentrations (10-100 µM), probably by deprotonation of this labile cyt b559 form [7].…”

Section: Plants and Algaementioning

confidence: 98%

Copper and Copper-Containing Pesticides: Metabolism, Toxicity and Oxidative Stress

Husak

2015

jpnu

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Abstract. The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals), because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD), and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

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Form and Function of Cytochrome b-559

Cited by 40 publications

References 103 publications

The initial steps of biogenesis of cyanobacterial photosystems occur in plasma membranes

The initial steps of biogenesis of cyanobacterial photosystems occur in plasma membranes

Mollusc-Algal Chloroplast Endosymbiosis. Photosynthesis, Thylakoid Protein Maintenance, and Chloroplast Gene Expression Continue for Many Months in the Absence of the Algal Nucleus

Copper and Copper-Containing Pesticides: Metabolism, Toxicity and Oxidative Stress

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