Identification of a calmodulin-regulated autoinhibited Ca2+-ATPase (ACA11) that is localized to vacuole membranes in Arabidopsis.
In plant cells, the vacuole functions as a major calcium store. Although a calmodulin-regulated Ca2+-ATPase (ACA4) is known to be present in prevacuolar compartments, the presence of an ACA-type Ca2+-ATPase in the mature vacuole of a plant cell has not been verified. Here we provide evidence that ACA11 localizes to the vacuole membrane. ACA11 tagged with GFP was expressed in stable transgenic plants, and visualized in root cells and protoplasts by confocal microscopy. A Ca2+-ATPase function for ACA11 was confirmed by complementation of yeast mutants. A calmodulin binding domain was identified within the first 37 residues of the N-terminal autoinhibitory region.
Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea.
Sang Min
SM
Lee
Ho Soo
HS
Kim
Hay Ju
HJ
Han
Byeong Cheol
BC
Moon
Cha Young
CY
Kim
Jeffery F
JF
Harper
Woo Sik
WS
Chung
D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D005816:Genetic Complementation Test; D018613:Microscopy, Confocal; D018517:Plant Roots / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000502:physiology; D011523:Protoplasts / Q000166:cytology / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014617:Vacuoles / Q000201:enzymology* / Q000235:genetics
D029681:Arabidopsis Proteins; D002147:Calmodulin; C523484:ACA11 protein, Arabidopsis; C419649:ACA4 protein, Arabidopsis; D000252:Calcium-Transporting ATPases