Upregulation of vacuolar H(+)-translocating pyrophosphatase by phosphate starvation of Brassica napus (rapeseed) suspension cell cultures.
The influence of phosphate (Pi) deprivation on the vacuolar H(+)-translocating pyrophosphatase (PPiase) and ATPase in tonoplast vesicles from Brassica napus suspension cells was assessed. Pi starvation significantly elevated the ratios of PPi-:ATP-dependent H(+) translocation rate and H(+)-PPiase:H(+)-ATPase hydrolytic activities. These increases were reversed 36 h following resupply of 2.5 mM Pi to the Pi-starved cells. Immunoblotting indicated that Pi starvation also induced a two-fold increase in the amount of H(+)-PPiase protein, whereas the amount of H(+)-ATPase remained unchanged. It is proposed that H(+)-PPiase facilitates the conservation of limited ATP pools, and Pi recycling during Pi stress.
Palma
D A
DA
Department of Biology, Queen's University, Kingston, Canada.
Blumwald
E
E
Plaxton
W C
WC
D000135:Acid Phosphatase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001692:Biological Transport; D001937:Brassica / Q000201:enzymology*; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division; D002478:Cells, Cultured; D003470:Culture Media; D006859:Hydrogen / Q000378:metabolism; D006868:Hydrolysis; D043564:Inorganic Pyrophosphatase; D010710:Phosphates / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011755:Pyrophosphatases / Q000378:metabolism*; D015854:Up-Regulation; D025262:Vacuolar Proton-Translocating ATPases
D003470:Culture Media; D010710:Phosphates; D006859:Hydrogen; D000255:Adenosine Triphosphate; D000135:Acid Phosphatase; D011755:Pyrophosphatases; D025262:Vacuolar Proton-Translocating ATPases; D043564:Inorganic Pyrophosphatase; D006180:Proton-Translocating ATPases