Activation of the H+-ATP synthase in thylakoid vesicles from the cyanobacterium Synechococcus 6716 by Δ\̄gmH+. Including a comparison with chloroplasts, and introducing a new method to calibrate light-induced Δ\̄gmH+

Krab, Klaas; Bakels, R.H.A.; Scholts, M.J.C.; Walraven, H.S. van

doi:10.1016/0005-2728(93)90043-f

Cited by 20 publications

(14 citation statements)

References 16 publications

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“…It has been suggested that in the preparation of broken chloroplasts, a factor necessary for deactivation of the chloroplast ATP synthase is washed away (10). Immediately upon isolation, broken chloroplasts from barley show an ATP synthase with ATP hydrolysis activity, in contrast to spinach chloroplasts where the ATP synthase is not active (31). In isolated broken chloroplasts from barley, the ATP hydrolysis rate slowly decreased when chloroplasts were stored on ice in the dark (Fig.…”

Section: -3-3 Rapidlymentioning

confidence: 93%

“…ATP hydrolysis activities were determined by scalar proton release measured with a sensitive pH electrode, as described in Krab et al (31). The reaction medium (2 ml) contained 2 mM Tricine-NaOH, 5 mM MgCl 2 , 50 mM KCl, 50 mM NaCl and 2.5 mM K 2 HPO 4 at pH 8.0.…”

Section: Purification Of Mitochondrial (M)fof1 and Chloroplast (C)fofmentioning

confidence: 99%

“…In contrast to the mitochondrial enzyme, the chloroplast ATP synthase shows a complex regulation of catalytic activity (5,31). A high value of the proton motive force (⌬ Hϩ ) across the thylakoid membrane favors a high rate of ATP synthesis.…”

Section: -3-3 Rapidlymentioning

confidence: 99%

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14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase

Bunney

Walraven

Boer

2001

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

182

124

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Mitochondrial and chloroplast ATP synthases are key enzymes in plant metabolism, providing cells with ATP, the universal energy currency. ATP synthases use a transmembrane electrochemical proton gradient to drive synthesis of ATP. The enzyme complexes function as miniature rotary engines, ensuring energy coupling with very high efficiency. Although our understanding of the structure and functioning of the synthase has made enormous progress in recent years, our understanding of regulatory mechanisms is still rather preliminary. Here we report a role for 14-3-3 proteins in the regulation of ATP synthases. These 14-3-3 proteins are highly conserved phosphoserine͞phosphothreonine-binding proteins that regulate a wide range of enzymes in plants, animals, and yeast. Recently, the presence of 14-3-3 proteins in chloroplasts was illustrated, and we show here that plant mitochondria harbor 14-3-3s within the inner mitochondrial-membrane compartment. There, the 14-3-3 proteins were found to be associated with the ATP synthases, in a phosphorylation-dependent manner, through direct interaction with the F 1 ␤-subunit. The activity of the ATP synthases in both organelles is drastically reduced by recombinant 14-3-3. The rapid reduction in chloroplast ATPase activity during dark adaptation was prevented by a phosphopeptide containing the 14-3-3 interaction motif, demonstrating a role for endogenous 14-3-3 in the down-regulation of the CF oF1 activity. We conclude that regulation of the ATP synthases by 14-3-3 represents a mechanism for plant adaptation to environmental changes such as light͞dark transitions, anoxia in roots, and fluctuations in nutrient supply.

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Section: -3-3 Rapidlymentioning

confidence: 93%

Section: Purification Of Mitochondrial (M)fof1 and Chloroplast (C)fofmentioning

confidence: 99%

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14-3-3 protein is a regulator of the mitochondrial and chloroplast ATP synthase

Bunney

Walraven

Boer

2001

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

182

124

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“…For mutants the medium was supplemented with 25 mg/l kanamycin, because kanamycin resistance was used as a selection marker [8]. For this reason control experiments were also performed with a Light-induced ATP synthesis activity was measured by the uptake of scalar protons measured with a sensitive pH electrode [ 121 in a setup as described by Krab et al [5]. The reaction medium contained 2 mM Tricine/NaOH (pH 8.0) with 5 mM MgC12, 50 mM KCl, 50 mM NaCl, 2.5 mM K2HP04, 50 pM phenazinemethosulphate, 1 mM 6-amino-n-caproic acid, 100 pM PMSF and 1.5 mM ADP.…”

Section: Methodsmentioning

confidence: 99%

“…Functionally the cyanobacterial enzyme (FIFO) resembles the reduced form of CFIFo in that the A,&+ required for activation is low, and the active form is quite stable [5].…”

Section: Introductionmentioning

confidence: 99%