Kettner, C. ; Obermeyer, G. ; Bertl, A. (2003)
Inhibition of the yeast V-type ATPase by cytosolic ADP.
In: FEBS letters, 535 (1-3)
doi: 10.1016/S0014-5793(02)03886-3
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The activity of the vacuolar H(+)-ATPase has been characterized in isolated vacuoles of the yeast Saccharomyces cerevisiae by means of the patch-clamp technique. With cytosolic calcium at virtually zero (<10(-9) M), Mg-ATP induced a transient, bafilomycin A(1)-sensitive current corresponding to the flow of positive charges from the cytoplasmic surface to the vacuolar lumen. The Mg-ATP-dependent current reached its maximum amplitude (30+/-8 mA m(-2) with 5 mM Mg-ATP, n=34) within 15-20 s and declined slowly over a period of about 15-20 min even in the continuous presence of Mg-ATP. This decline of pumping activity was independent of the cytosolic KCl concentration, suggesting an inhibitory mechanism different from the high salt-induced dissociation of V(0) and V(1) reported for the V-ATPase of plants and fungi. Cytosolic ADP was found to modulate the pump activity since Mg-ATP-induced pump current was smaller if monitored in the presence of 5 mM ADP and addition of 5 mM ADP in the presence of 5 mM Mg-ATP reduced the pump current by more than 50%. Furthermore, reduction of the cytosolic ADP concentration by the ATP-regenerating system creatine phosphate/creatine kinase partially relieved the endogenous inhibition of the V-ATPase, confirming that interaction of cytosolic ADP with the V-ATPase is the reason for the transient nature of the pump current in yeast vacuoles.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2003 |
| Autor(en): | Kettner, C. ; Obermeyer, G. ; Bertl, A. |
| Art des Eintrags: | Bibliographie |
| Titel: | Inhibition of the yeast V-type ATPase by cytosolic ADP. |
| Sprache: | Englisch |
| Publikationsjahr: | 2003 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | FEBS letters |
| Jahrgang/Volume einer Zeitschrift: | 535 |
| (Heft-)Nummer: | 1-3 |
| DOI: | 10.1016/S0014-5793(02)03886-3 |
| Kurzbeschreibung (Abstract): | The activity of the vacuolar H(+)-ATPase has been characterized in isolated vacuoles of the yeast Saccharomyces cerevisiae by means of the patch-clamp technique. With cytosolic calcium at virtually zero (<10(-9) M), Mg-ATP induced a transient, bafilomycin A(1)-sensitive current corresponding to the flow of positive charges from the cytoplasmic surface to the vacuolar lumen. The Mg-ATP-dependent current reached its maximum amplitude (30+/-8 mA m(-2) with 5 mM Mg-ATP, n=34) within 15-20 s and declined slowly over a period of about 15-20 min even in the continuous presence of Mg-ATP. This decline of pumping activity was independent of the cytosolic KCl concentration, suggesting an inhibitory mechanism different from the high salt-induced dissociation of V(0) and V(1) reported for the V-ATPase of plants and fungi. Cytosolic ADP was found to modulate the pump activity since Mg-ATP-induced pump current was smaller if monitored in the presence of 5 mM ADP and addition of 5 mM ADP in the presence of 5 mM Mg-ATP reduced the pump current by more than 50%. Furthermore, reduction of the cytosolic ADP concentration by the ATP-regenerating system creatine phosphate/creatine kinase partially relieved the endogenous inhibition of the V-ATPase, confirming that interaction of cytosolic ADP with the V-ATPase is the reason for the transient nature of the pump current in yeast vacuoles. |
| Fachbereich(e)/-gebiet(e): | 10 Fachbereich Biologie ?? fb10_botanik ?? 10 Fachbereich Biologie > Yeast Membrane Biology |
| Hinterlegungsdatum: | 29 Nov 2010 15:25 |
| Letzte Änderung: | 05 Mär 2013 09:41 |
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