Functional identification of ATP‐driven Ca2+ pump in the peribacteroid membrane of broad bean root nodules

FEBS Letters

Dubrovo, Pavel N.¹  Krylova, Valeria V.¹  Izmailov, Stanislav F.¹  Andreev, Igor M.¹ 

[1]Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow 127276, Russia

关键词: ATP-dependent Ca2+ transport;    Ca2+-ATPase;    Symbiosome;    Peribacteroid membrane;    Vicia faba L;    PBM;    peribacteroid membrane;    ATP;    adenosine-5′-triphosphate;    EGTA;    ethylene glycol-bis(β-aminoethyl ether)-N;    N;    N′;    N′-tetraacetic acid;    CTC;    chlortetracycline;    BTP;    1;    3-bis(tris(hydroxymethyl)methylamino)propane;    HEPES;    N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid;    MES;    2-[N-morpholino]ethanesulfonic acid;    FCCP;    carbonylcyanide-p-trifluoromethoxy-phenylhydrazone;    oxonol YI;    bis93-propyl-5-oxoisoxazol-4-yl)pentamethine oxonol;    Δψ;    membrane potential;    ΔpH;    transmembrane pH difference;   

DOI  :  10.1016/S0014-5793(99)00262-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A Ca²⁺ indicator arsenazo III was used to demonstrate calcium uptake activity of symbiosomes and the peribacteroid membrane (PBM) vesicles isolated from broad bean root nodules and placed in the medium containing ATP and Mg²⁺ ions. This process was shown to be rapidly stopped by vanadate, completely reversed in the presence of the calcium ionophore A23187 but insensitive to agents abolishing electrical potential or pH difference across the PBM. The presence of an endogenous calcium pool within isolated symbiosomes and bacteroids was detected using a Ca²⁺ indicator chlortetracycline. These results prove a primary active transport of Ca²⁺ through the PBM of legume root nodules and provide the first functional identification of an ATP-driven Ca²⁺-pump, most likely Mg²⁺-dependent Ca²⁺-translocating ATPase, in this membrane.

【 授权许可】

Unknown