The acidification of endomembrane compartments is essential for enzyme activities, sorting, trafficking, and trans-membrane transport of various compounds. Vacuoles are mildly acidic inmost plant cells because of the action of V-ATPase and/or pyrophosphatase proton pumps but are hyperacidified in specific cells by mechanisms that remained unclear. Here, we show that the blue petal color of petunia ph mutants is due to a failure to hyperacidify vacuoles. We report that PH1 encodes a P3BATPase, hitherto known as Mg2+ transporters in bacteria only, that resides in the vacuolar membrane (tonoplast). In vivo nuclear magnetic resonance and genetic data show that PH1 is required and, together with the tonoplast H+ P3A-ATPase PH5, sufficient to hyperacidify vacuoles. PH1 has no H+ transport activity on its own but can physically interact with PH5 and boost PH5 H+ transport activity. Hence, the hyperacidification of vacuoles in petals, and possibly other tissues, relies on a heteromeric P-ATPase pump.
Hyperacidification of Vacuoles by the Combined Action of Two Different P-ATPases in the Tonoplast Determines Flower Color / M. Faraco, C. Spelt, M. Bliek, W. Verweij, A. Hoshino, L. Espen, B. Prinsi, R. Jaarsma, E. Tarhan, A.H. de Boer, G. Di Sansebastiano, R. Koes, F.M. Quattrocchio. - In: CELL REPORTS. - ISSN 2211-1247. - 6:1(2014 Jan 16), pp. 32-43. [10.1016/j.celrep.2013.12.009]
Hyperacidification of Vacuoles by the Combined Action of Two Different P-ATPases in the Tonoplast Determines Flower Color
L. Espen;B. Prinsi;
2014
Abstract
The acidification of endomembrane compartments is essential for enzyme activities, sorting, trafficking, and trans-membrane transport of various compounds. Vacuoles are mildly acidic inmost plant cells because of the action of V-ATPase and/or pyrophosphatase proton pumps but are hyperacidified in specific cells by mechanisms that remained unclear. Here, we show that the blue petal color of petunia ph mutants is due to a failure to hyperacidify vacuoles. We report that PH1 encodes a P3BATPase, hitherto known as Mg2+ transporters in bacteria only, that resides in the vacuolar membrane (tonoplast). In vivo nuclear magnetic resonance and genetic data show that PH1 is required and, together with the tonoplast H+ P3A-ATPase PH5, sufficient to hyperacidify vacuoles. PH1 has no H+ transport activity on its own but can physically interact with PH5 and boost PH5 H+ transport activity. Hence, the hyperacidification of vacuoles in petals, and possibly other tissues, relies on a heteromeric P-ATPase pump.File | Dimensione | Formato | |
---|---|---|---|
1-s2.0-S2211124713007547-main.pdf
accesso aperto
Tipologia:
Publisher's version/PDF
Dimensione
2.42 MB
Formato
Adobe PDF
|
2.42 MB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.