Oxidative phosphorylation in intact cyanobacteria

Nitschmann, Wolfgang H.; Peschek, Günter A.

doi:10.1016/0014-5793(82)80491-2

Cited by 48 publications

(19 citation statements)

References 26 publications

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“…The light requirement for restoration of PSII activity must exist for some step(s) subsequent to entry of Ca2+ (or Na+) into the cells. Sodium enters Anacystis readily in a passive process, dependent only upon concentration gradient (22). Once again, Na+ apparently parallels Ca2e flux, and we suggest that our interpretation of45Ca2+ data applies also in cases of Nae substitution for Ca2'.…”

Section: Restoration Oflost Photosynthetic 02 Evolution In Anacystis supporting

confidence: 52%

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺

Becker¹,

Brand²

1985

Plant Physiol.

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ABSTRACITAnacystis nidulans exhibits a total loss of photosystem II (PSII) activity upon incubation in a nutrient medium deficient in Ca2' and Na' and containing a divalent cation chelator. This loss of activity is lightdependent, which corresponds to an energy requirement. Likewise, Ca2' efflux takes place only in cells incubated in light. The loss of PSII activity is reversible by addition of submillimolar amounts of either Ca2' or Na' to the external medium but not by the addition of any other cation. Restoration of lost PSII activity also requires light. Light saturation curves for partially depleted cells demonstrate both lower maximum 02 evolution rates and decreased relative quantum yields when compared to control cells. Partial electron transport reactions isolate the site of the Ca2'/Na' effect to the reaction center itself or immediately on its oxidizing side and exclude the water-splitting complex. 02 flash yields decline during cation depletion, indicating a decrease in the number of functional PSII reaction centers, but the maximum turnover rate for still functional reaction centers does not decline. Thus, PSII of A. nidulans exhibits an all-or-none cation requirement, satisfied only by Ca2 or Na'.Early preparations of photosynthetic membranes from cyanobacteria required divalent cations for maximal activity (12,31 (7). We report here a full description of conditions necessary for the reversible loss of PSII activity in intact Anacystis, including the startling finding that Na+ substitutes for Ca2" in this system. We also demonstrate that the site of action for these cations is very near the reaction center. A summary of portions of this work has been presented at a symposium (4). MATERIALS AND METHODSCell Growth and Incubation Conditions. Cg-10 medium was prepared in 3-L batches from stock solutions as described in (32) except that the Fe-EDTA stock solution was prepared from the free acid form of EDTA and the final glycylycine concentration was 11 mm. Acid-washed (0.2 N HCI) glassware was used throughout to minimize cation contamination and the medium was sterilized by autoclaving prior to use. The pH was adjusted to 8.3 with KOH.Anacystis (UTEX 625, Collection of Algae, University of Texas, Austin) was grown at 39C in continuous culture in nutrient medium (28). Cell suspensions of approximately 2 x 108 cells ml-' were aerated continuously with 1.2% CO2 in air and illuminated at approximately 50 uE m-2 s-' PAR with F20T12-CW fluorescent lamps. Cells were harvested, pelleted at 2000g for 10 min, then resuspended to the original cell density in Cg-10 medium devoid of Ca2+. The suspension was pelleted a second time and resuspended in a small volume ofCa2`deficient

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Section: Restoration Oflost Photosynthetic 02 Evolution In Anacystis supporting

confidence: 52%

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺

Becker¹,

Brand²

1985

Plant Physiol.

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“…ATP levels reached within 5 s after the jump are given as % of corresponding steady-state levels dicated by the effect of p-chloromercuribenzoate (table 1) which conforms to previous findings with membrane-bound ATPases [24]. Complete lack of inhibition by carbon monoxide, which is a potent inhibitor of cyanobacterial terminal oxidases [25,26], safely excludes any ATP formation by oxidative phosphorylation [18,19] due to trace amounts of oxygen inadvertently introduced in the course of acid pulse experiments. Fig.3 attempts to summarize our present knowledge of membrane-bound bioenergetic mechanisms in cyanobacteria: Thylakoid membranes are shown to contain an electron transport system capable of serving both respiration and photosynthesis through common carriers, viz.…”

Section: Methodssupporting

confidence: 87%

“…plastoquinone and the cytochrome fIba complex [27,28]. In addition, the cytoplasmic membrane (of A. niduluns) appears to be endowed with respiratory functions [14][15][16][17][18][19]291. In particular, a cytoplasmic membrane-bound cytochrome oxidase, presumably of aa3-type [25,26,30], might establish a transmembrane proton electrochemical gradient through active proton extrusion [ similarly cytoplasmic membrane-bound ATPase to drive ATP synthesis as discussed here.…”

Section: Methodsmentioning

confidence: 99%

pH‐jump‐induced phosphorylation of ADP in the cyanobacterium Anacystis nidulans

Muchl

Peschek

1983

FEBS Letters

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The low ATP levels in dark anaerobic cells of the cyanobacterium Anacystis nidulans more than doubled within 5 s after rapid addition of HCl shifting external pH from 9.0 to 4.5. Steady-state levels of ATP and intracellular pH remained constant at 0.95 * 0.15 nmol/mg dry weight and 6.9 k 0.3, respectively. ApH-induced ATP synthesis was inhibited by dicyclohexylcarbodiimide and carbonyl cyanide mchlorophenylhydrazone but not by carbon monoxide. According to our results the cytoplasmic membrane of A. nidulans has to be regarded as an energy-transducing membrane bioenergetically similar to the thylakoid membrane. pH gradientProtonmotive force Cytoplasmic membrane

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“…The energyconsuming Na + extrusion reduces the efficiency of oxidative phosphorylation in A. nidulans and this has been correlated with its failure to grow in the dark while in two other facultatively chemoheterotrophic cyanobacteria, A . variabilis and Nostoc MAC, oxidative phosphorylation is much less sensitive to Na' [12]. It is noteworthy that A .…”

Section: Discussionmentioning

confidence: 86%

“…The respiratory and photosynthetic electron transport chains are generally believed to be located on the thylakoids in cyanobacteria [29] and presumably can not generate a proton gradient. Recently a plasmalemma-bound respiratory aa3 type of cytochrome oxidase has been implicated as a non-ATP-requiring proton pump in cyanobacteria [12] although the evidence is not unequivocal. From the present study of two N2-fixing Anahaena spp.…”

Section: Discussionmentioning

confidence: 99%

Membrane electrogenesis and sodium transport in filamentous nitrogen-fixing cyanobacteria

Apte

Thomas

1986

Eur J Biochem

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Transport of Na+ and its relationship with membrane potential (ΔΨm) was examined in Anabaena L‐31 (a fresh water cyanobacterium) and Anabaena torulosa (a brackish water cyanobacterium) which require Na+ for diazotrophic growth. The data on the effect of N,N′‐dicyclohexylcarbodiimide indicated that ΔΨm was generated by electrogenic proton extrusion predominantly mediated by ATPase(s). In addition, operation of a plasmalemmabound, non‐ATP‐requiring, H+ ‐pumping terminal oxidase was suggested by the sensitivity of ΔΨm to anaerobiosis, cyanide and azide, all of which inhibit aerobic respiration. The response of ΔΨm to external pH and external Na+ or K+ concentrations indicated that a diffusion potential of Na+ or K+ may not contribute significantly to ΔΨm. Kinetic studies showed that Na+ influx was unlikely to be a result of Na+/Na+ exchange but was a carrier‐mediated secondary active transport insensitive to low concentrations (< 10 mM) of external K+. There was a close correspondence between changes in ΔΨm and Na+ influx; all the treatments which caused depolarisation (such as low temperature, dark, cyanide, azide, anaerobiosis, ATPase inhibitors) lowered Na+ influx whereas treatments which caused hyperpolarisation (such as 2,4‐dinitrophenol, nigericin) enhanced Na+ influx. Remarkably low intracellular Na+ concentrations were maintained by these cyanobacteria by means of active efflux of the cation. The basic mechanism of Na+ transport in the fresh water and the brackish water cyanobacterium was similar but the latter demonstrated less influx, more efficient efflux, more affinity of carriers for Na+ and less accumulation of Na+, all attributes favouring salt tolerance.

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Oxidative phosphorylation in intact cyanobacteria

Cited by 48 publications

References 26 publications

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺

pH‐jump‐induced phosphorylation of ADP in the cyanobacterium Anacystis nidulans

Membrane electrogenesis and sodium transport in filamentous nitrogen-fixing cyanobacteria

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Oxidative phosphorylation in intact cyanobacteria

Cited by 48 publications

References 26 publications

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca2+ or Na+

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca2+ or Na+

pH‐jump‐induced phosphorylation of ADP in the cyanobacterium Anacystis nidulans

Membrane electrogenesis and sodium transport in filamentous nitrogen-fixing cyanobacteria

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Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺

Anacystis nidulans Demonstrates a Photosystem II Cation Requirement Satisfied Only by Ca²⁺ or Na⁺