Induction of SULTR1;1 sulfate transporter in Arabidopsis roots involves protein phosphorylation/dephosphorylation circuit for transcriptional regulation.
SULTR1;1 high-affinity sulfate transporter is highly regulated by sulfur deficiency (-S) in the epidermis and cortex of Arabidopsis roots. The regulatory mechanism of SULTR1;1 expression was studied using inhibitors for transcription, translation, protein phosphorylation and dephosphorylation. The induction of SULTR1;1 mRNA during -S was blocked by the addition of actinomycin D in the medium, suggesting that SULTR1;1 is transcriptionally regulated. Cycloheximide repressed the -S induction of SULTR1;1, but enhanced the basal mRNA level of SULTR1;1 under sulfur replete (+S) condition. In addition, the induction of SULTR1;1 by -S was significantly blocked by okadaic acid (OKA) and calyculin A (CalyA). Regulation of SULTR1;1 was further confirmed in transgenic plants expressing green fluorescent protein (GFP) under the control of SULTR1;1 promoter. Accumulation of GFP during -S was dependent to SULTR1;1 promoter, and the effects of OKA and CalyA were reproducible in the SULTR1;1 promoter-GFP plants. These results suggested that the up-regulation of SULTR1;1 by -S requires protein phosphatase as an upstream regulatory factor.
Maruyama-Nakashita
Akiko
A
RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan.
Nakamura
Yumiko
Y
Watanabe-Takahashi
Akiko
A
Yamaya
Tomoyuki
T
Takahashi
Hideki
H
D027321:Anion Transport Proteins; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008387:Marine Toxins; D026901:Membrane Transport Proteins; D019319:Okadaic Acid / Q000494:pharmacology; D010080:Oxazoles / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D000076988:Sulfate Transporters; D013455:Sulfur / Q000172:deficiency / Q000378:metabolism
D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D008164:Luminescent Proteins; D008387:Marine Toxins; D026901:Membrane Transport Proteins; D010080:Oxazoles; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; C455459:Sultr1;1 protein, Arabidopsis; D049452:Green Fluorescent Proteins; D003609:Dactinomycin; D019319:Okadaic Acid; D013455:Sulfur; C059041:calyculin A; D003513:Cycloheximide