Abstract
It was shown before (Wooten, D. C., and Dilley, R. A. (1993) J. Bioenerg. Biomembr. 25, 557–567; Zakharov, S. D., Li, X., Red'ko, T. P., and Dilley, R. A. (1996) J. Bioenerg. Biomembr. 28, 483–493) that pH dependent reversible Ca2+ binding near the N- and C-terminal end of the 8 kDa subunit c modulates ATP synthesis driven by an applied pH jump in chloroplast and E. coli ATP synthase due to closing a “proton gate” proposed to exist in the F0 H+ channel of the F0F1 ATP synthase. This mechanism has further been investigated with the use of membrane vesicles from mutants of the cyanobacterium Synechocystis 6803. Vesicles from a mutant with serine at position 37 in the hydrophilic loop of the c-subunit replaced by the charged glutamic acid (strain plc 37) has a higher H+/ATP ratio than the wild type and therefore shows ATP synthesis at low values of Δμ H +. The presence of 1 mM CaCl2 during the preparation and storage of these vesicles blocked acid–base jump ATP formation when the pH of the acid side (inside) was between pH 5.6 and 7.1, even though the ΔpH of the acid–base jump was thermodynamically in excess of the necessary energy to drive ATP formation at an external pH above 8.28. That is, in the absence of added CaCl2, ATP formation did occur under those conditions. However, when the base stage pH was 7.16 and the acid stage below pH 5.2, ATP was formed when Ca2+ was present. This is consistent with Ca2+ being displaced by H+ ions from the F0 on the inside of the thylakoid membrane at pH values below about 5.5. Vesicles from a mutant with the serine of position 3 replaced by a cysteine apparently already contain some bound Ca2+ to F0. Addition of 1 mM EGTA during preparation and storage of those vesicles shifted the otherwise already low internal pH needed for onset of ATP synthesis to higher values when the external pH was above 8. With both strains it was shown that the Ca2+ binding effect on acid–base induced ATP synthesis occurs above an internal pH of about 5.5. These results were corroborated by 45Ca2+- ligand blot assays on organic solvent soluble preparations containing the 8 kDa F0 subunit c from the S-3-C mutant ATP synthase, which showed 45Ca2+ binding as occurs with the pea chloroplast subunit III. The phosphorylation efficiency (P/2e), at strong light intensity, of Ca2+ and EGTA treated vesicles from both strains were almost equal showing that Ca2+ or EGTA have no other effect on the ATP synthase such as a change in the proton to ATP ratio. The results indicate that the Ca2+ binding to the F0 H+ channel can block H+ flux through the channel at pH values above about 5.5, but below that pH protons apparently displace the bound Ca2+, opening the CF0 H+ channel between the thylakoid lumen and H+ conductive channel.
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REFERENCES
Arakaki, N., Ueyama, Y., Hirose, M., Himeda, T., Shibata, H., Futaki, S., Kitagawa, K., and Higuti, T. (2001). Biochim. Biophys. Acta 1504, 220–228.
Arnon, D. I., McSwain, B. D., Tsujimoto, H. Y., and Wada, K. (1974). Biochim. Biophys. Acta 357, 231–245.
Beard, W. A., and Dilley, R. A. (1988). J. Bioeneg. Biomembr. 20, 129–154.
Bergmeyer, H. U. (1970). Method der Enzymatische Analyse, Verlag Chemie, Weinheim, Germany.
Berry, S., and Rumberg, B. (1999). Biochim. Biophys. Acta 1410, 248–261.
Chiang, G. G., and Dilley, R. A. (1987). Biochemistry 26, 4911–4916.
Chiang, G., Wooten, D., and Dilley, R. A. (1992). Biochemistry 31, 5808–5819.
Demmig-Adams, B. (1990). Biochim. Biophys. Acta 1020, 1–24.
Dilley, R. A. (1991). Curr. Top. Bioenerg. 16, 265–317.
Dilley, R. A., and Chiang, G. G. (1989). Ann. NY Acad. Sci. 574, 246–267.
Dilley, R. A., Theg, S. M., and Beard, W. A. (1987). Annu. Rev. Plant Physiol. 38, 348–389.
Fillingame, R. H., Jiang, W., Dmitriev, O. Y., and Jones, P. C. (2000). Biochim. Biophys. Acta 1458, 387–403.
Gilmore, A. M. (1997). Physiol. Plantarum 99, 197–209.
Hangarter, R. P., Grandoni, P., and Ort, D. R. (1987). J. Biol. Chem. 262, 13513–13519.
Jagendorf, A. T., and Avron, M. (1959). Arch. Biochem. Biophys. 80, 246–257.
Junesch, U., and Gräber, P. (1985). Biochim. Biophys. Acta 809, 429–434.
Krab, K., Bakels, R. H. A.,Scholts, M. J. C., and Van Walraven, H. S. (1993). Biochim. Biophys. Acta 1141, 197–205.
Krab, K., and Van Wezel, J. (1992). Biochim. Biophys. Acta 1098, 172–176.
Krenn, B. E., Van Walraven, H. S., Scholts, M. J. C., and Kraayenhof, R. (1993). Biochem. J. 294, 705–709.
Krieger, A., and Weis, E. (1993). Photosynth. Res. 37, 117–130.
Lubberding, H. J., and Bot, P. V. M. (1984). Arch. Microbiol. 137, 115–120.
Maruyama, K., Mikawa, T., and Ebashi, S. (1984). J. Biochem. (Tokyo) 95, 511–519.
Massom, L., Lee, H., and Jarrett, H. W. (1990). Biochemistry 29, 671–681.
Mc Phelan, C. A., Strynadka, N. J. C., and James, M. N. G. (1991). Adv Protein Chem. 42, 77–144.
Moody, M. F., Jones, P. T., Carver, J. A., Boyd, J., and Campbell, I. D. (1987). J. Mol. Biol. 193, 759–774.
Pan, R. S., and Dilley, R. A. (2000). Photosynth. Res. 65, 141–154.
Prozialeck, W. C., Cimino, M., and Weiss, B. (1981). Mol. Pharmacol. 19, 264–269.
Roberts, D. M., Lukas, T. J., and Watterson, D. M. (1986). CRC Rev. Plant Sci. 4, 311–339.
Scholts, M. J. C., Aardewijn, P., and Van Walraven, H. S. (1996). Photosynth. Res. 47, 301–305.
VanWalraven, H. S., Scholts, M. J. C., Lill, H., Matthijs, H. C. P., Dilley, R. A., and Kraayenhof, R. (2002). J. Bioenerg. Biomembr. 34, 455–464.
Weber, J., and Senior, A.E. (1997). Biochim. Biophys. Acta 1319, 19–58.
Wooten, D. C., and Dilley, R. A. (1993). J. Bioenerg. Biomembr. 25, 557–567.
Zakharov, S. D., Ewy, R. G., and Dilley, R. A. (1993). FEBS Lett. 336, 95–99.
Zakharov, S. D., Ewy, R. G., and Dilley, R. A. (1995). Protoplasma 184, 42–49
Zakharov, S. D., Li, X., Red'ko, T. P., and Dilley, R. A. (1996). J. Bioenerg. Biomembr. 28, 483–493.
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Walraven, H.S.V., Scholts, M.J.C., Zakharov, S.D. et al. pH-Dependent Ca2+ Binding to the F0 c-Subunit Affects Proton Translocation of the ATP Synthase from Synechocystis 6803. J Bioenerg Biomembr 34, 455–464 (2002). https://doi.org/10.1023/A:1022518109371
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DOI: https://doi.org/10.1023/A:1022518109371