Potassium as an intrinsic uncoupler of the plasma membrane H+-ATPase
Publikation: Konferencebidrag › Konferenceabstrakt til konference › Forskning
The plant plasma membrane proton pump (H(+)-ATPase) is stimulated by potassium, but it has remained unclear whether potassium is actually transported by the pump or whether it serves other roles. We now show that K(+) is bound to the proton pump at a site involving Asp(617) in the cytoplasmic phosphorylation domain, from where it is unlikely to be transported. Binding of K(+) to this site can induce dephosphorylation of the phosphorylated E(1)P reaction cycle intermediate by a mechanism involving Glu(184) in the conserved TGES motif of the pump actuator domain. Our data identify K(+) as an intrinsic uncoupler of the proton pump and suggest a mechanism for control of the H(+)/ATP coupling ratio. K(+)-induced dephosphorylation of E(1)P may serve regulatory purposes and play a role in negative regulation of the transmembrane electrochemical gradient under cellular conditions where E(1)P is accumulating.
Originalsprog | Engelsk |
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Publikationsdato | 2006 |
Antal sider | 1 |
Status | Udgivet - 2006 |
Begivenhed | Plant Transporters Meeting - Wye, Storbritannien Varighed: 4 sep. 2006 → 6 sep. 2006 |
Konference
Konference | Plant Transporters Meeting |
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Land | Storbritannien |
By | Wye |
Periode | 04/09/2006 → 06/09/2006 |
Bibliografisk note
Sider: 7
ID: 8048473