Ca2+/H+ antiport as a possible mechanism of the Ca2+-translocating ATPase functioning in vesicles of bean root nodule’s symbiosome membrane
- Authors: Krylova V.V.1, Zartdinova R.F.1, Andreev I.M.1, Izmailov S.F.1
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Affiliations:
- Timiryazev Institute of Plant Physiology
- Issue: Vol 10, No 3 (2016)
- Pages: 218-222
- Section: Articles
- URL: https://journals.rcsi.science/1990-7478/article/view/213196
- DOI: https://doi.org/10.1134/S1990747816010074
- ID: 213196
Cite item
Abstract
Using vesicles of symbiosome membrane (SM), it was shown that the Ca2+-ATPase can function as an ATP-energized Ca2+/H+ antiporter. The initial rate of the acidic shift inside the vesicles, as well as the rate of the ITP-dependent alkalization of the medium inside them markedly increased in the presence of valinomycin. This process was rapidly stopped by eosin Y, a known inhibitor of the type IIB Ca2+-ATPase. ITP-dependent uptake of Ca2+ was blocked after the addition to the reaction mixture of nigericin in the presence of K+. Under these conditions, the alkaline shift of pH inside the vesicles occurred, leading to the inhibition of operation of the calcium pump in SM. Evaluation of the pH shifts inside the vesicles by using pH-indicator pyranine confirmed the ion-exchange mechanism of the Ca2+-ATPase functioning in the SM.
About the authors
V. V. Krylova
Timiryazev Institute of Plant Physiology
Author for correspondence.
Email: krylovavv@list.ru
Russian Federation, ul. Botanicheskaya 35, Moscow, 127276
R. F. Zartdinova
Timiryazev Institute of Plant Physiology
Email: krylovavv@list.ru
Russian Federation, ul. Botanicheskaya 35, Moscow, 127276
I. M. Andreev
Timiryazev Institute of Plant Physiology
Email: krylovavv@list.ru
Russian Federation, ul. Botanicheskaya 35, Moscow, 127276
S. F. Izmailov
Timiryazev Institute of Plant Physiology
Email: krylovavv@list.ru
Russian Federation, ul. Botanicheskaya 35, Moscow, 127276