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 P-3B-ATPase, 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+ P-3A-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.

Autore Pugliese

• Di Sansebastiano Gian Pietro

Tutti gli autori

• Faraco M. , Spelt C. , Bliek M. , Verweij W. , Hoshino A. , Espen L. , Prinsi B. , Jaarsma R. , Tarhan E. , de Boer A.H , Di Sansebastiano G.P. , Koes R. , Quattrocchio F.M.

Titolo volume/Rivista

CELL REPORTS

Anno di pubblicazione

2014

ISSN

2211-1247

ISBN

Non Disponibile

Numero di citazioni Wos

36

Ultimo Aggiornamento Citazioni

28/04/2018

Numero di citazioni Scopus

37

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile