Regulation of Arabidopsis thaliana plasma membrane glucose-responsive regulator (AtPGR) expression by A. thaliana storekeeper-like transcription factor, AtSTKL, modulates glucose response in Arabidopsis

Plant Physiol Biochem. 2016 Jul;104:155-64. doi: 10.1016/j.plaphy.2016.03.029. Epub 2016 Mar 23.


Biochemical, genetic, physiological, and molecular research in plants has demonstrated a central role of glucose (Glc) in the control of plant growth, metabolism, and development, and has revealed networks that integrate light, stresses, nutrients, and hormone signaling. Previous studies have reported that AtPGR protein as potential candidates for Glc signaling protein. In the present study, we characterized transcription factors that bind to the upstream region of the AtPGR gene isolated using the yeast one-hybrid screening with an Arabidopsis cDNA library. One of the selected genes (AtSTKL) appeared to confer elevated sensitivity to Glc response. Overexpression of AtSTKLs (AtSTKL1 and AtSTKL2) increased the sensitivity to Glc during the post-germination stages. In contrast, atstkl1 and atstkl2 antisense lines displayed reduced sensitivity to high Glc concentration during the early seedling stage. Furthermore, we showed that the two AtSTKLs bind to the 5'-GCCT-3' element of the upstream promoter region of the AtPGR gene in vitro and repress the beta-glucuronidase (GUS) activity in AtPGR promoter-GUS (P999-GUS) transgenic plants. Green fluorescent protein (GFP)-tagged AtSTKLs were localized in the nuclei of transgenic Arabidopsis cells. Collectively, these results suggest that AtSTKL1 and AtSTKL2 function both as repressors of AtPGR transcription and as novel transcription factors in the Glc signaling pathway.

Keywords: AtPGR; AtSTKL; Glucose-responsive element; Repressor; Transcription factor.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / drug effects
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Cotyledon / drug effects
  • Cotyledon / genetics
  • DNA, Plant / genetics
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Plant* / drug effects
  • Genes, Plant
  • Glucose / pharmacology*
  • Glucuronidase / metabolism
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Molecular Sequence Data
  • Phylogeny
  • Plants, Genetically Modified
  • Promoter Regions, Genetic
  • Protein Binding / drug effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Repressor Proteins / chemistry
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Sequence Alignment
  • Sequence Deletion
  • Transcription, Genetic / drug effects
  • Transcriptional Activation / drug effects
  • Transcriptional Activation / genetics


  • Arabidopsis Proteins
  • DNA, Plant
  • Membrane Proteins
  • PGR protein, Arabidopsis
  • RNA, Messenger
  • Repressor Proteins
  • STKL1 protein, Arabidopsis
  • STKL2 protein, Arabidopsis
  • Glucuronidase
  • Glucose