Arabidopsis protein kinase PKS5 inhibits the plasma membrane H⁺ -ATPase by preventing interaction with 14-3-3 protein

TY - JOUR

T1 - Arabidopsis protein kinase PKS5 inhibits the plasma membrane H+ -ATPase by preventing interaction with 14-3-3 protein

AU - Fuglsang, Anja Thoe

AU - Guo, Yan

AU - Cuin, Tracey A.

AU - Qiu, Quansheng

AU - Song, Chunpeng

AU - Kristiansen, Kim Anker

AU - Bych, Katrine

AU - Schulz, Alexander

AU - Shabala, Sergey

AU - Schumaker, Karen S.

AU - Palmgren, Michael Gjedde

AU - Zhu, Jian-Kang

PY - 2007

Y1 - 2007

N2 - Regulation of the trans-plasma membrane pH gradient is an important part of plant responses to several hormonal andenvironmental cues, including auxin, blue light, and fungal elicitors. However, little is known about the signalingcomponents that mediate this regulation. Here, we report that an Arabidopsis thaliana Ser/Thr protein kinase, PKS5, is anegative regulator of the plasma membrane proton pump (PM Hþ-ATPase). Loss-of-function pks5 mutant plants are moretolerant of high external pH due to extrusion of protons to the extracellular space. PKS5 phosphorylates the PM Hþ-ATPaseAHA2 at a novel site, Ser-931, in the C-terminal regulatory domain. Phosphorylation at this site inhibits interaction betweenthe PM Hþ-ATPase and an activating 14-3-3 protein in a yeast expression system. We show that PKS5 interacts with thecalcium binding protein SCaBP1 and that high external pH can trigger an increase in the concentration of cytosolic-freecalcium. These results suggest that PKS5 is part of a calcium-signaling pathway mediating PM Hþ-ATPase regulation.

AB - Regulation of the trans-plasma membrane pH gradient is an important part of plant responses to several hormonal andenvironmental cues, including auxin, blue light, and fungal elicitors. However, little is known about the signalingcomponents that mediate this regulation. Here, we report that an Arabidopsis thaliana Ser/Thr protein kinase, PKS5, is anegative regulator of the plasma membrane proton pump (PM Hþ-ATPase). Loss-of-function pks5 mutant plants are moretolerant of high external pH due to extrusion of protons to the extracellular space. PKS5 phosphorylates the PM Hþ-ATPaseAHA2 at a novel site, Ser-931, in the C-terminal regulatory domain. Phosphorylation at this site inhibits interaction betweenthe PM Hþ-ATPase and an activating 14-3-3 protein in a yeast expression system. We show that PKS5 interacts with thecalcium binding protein SCaBP1 and that high external pH can trigger an increase in the concentration of cytosolic-freecalcium. These results suggest that PKS5 is part of a calcium-signaling pathway mediating PM Hþ-ATPase regulation.

U2 - 10.1105/tpc.105.035626

DO - 10.1105/tpc.105.035626

M3 - Journal article

C2 - 17483306

SN - 1040-4651

VL - 19

SP - 1617

EP - 1634

JO - Plant Cell

JF - Plant Cell

IS - 5

ER -