Functional analysis of light-regulated promoter region of AtPolλ gene

Planta. 2012 Feb;235(2):411-32. doi: 10.1007/s00425-011-1517-6. Epub 2011 Sep 25.


Genetic and molecular analyses mainly in Arabidopsis and in some other plants have demonstrated involvement of light signaling in cell cycle regulation. In this report, we show light-mediated activation of the promoter of AtPolλ gene, a homolog of mammalian DNA polymerase λ in Arabidopsis thaliana and an important component of DNA damage repair/recombination machinery in plants. Analyses of the light-mediated promoter activity using various deletion versions of AtPolλ promoter in transformed Arabidopsis and tobacco (Nicotiana tabaccum) plants indicate that a 130-bp promoter region between -536 and -408 of AtPolλ promoter is essential for light-induced regulation of AtPolλ expression. DNA-protein interaction studies reveal that an ATCT-motif and AE-box light-responsive elements in the light-regulated promoter region confer light responsiveness of AtPolλ promoter. DNA-binding analysis has identified a 63-kDa trans-acting protein factor which showed specific binding to ATCT-motif, while another trans-acting factor of ~52 kDa was found to bind specifically to both ATCT and AE-box sequences. The 52-kDa protein has been identified as B3-domain transcription factor by MALDI-TOF/MS analysis. Overall, our results provide novel information on the role of light signaling in regulation of expression of an important component of DNA repair machinery in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / enzymology
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / radiation effects*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Base Sequence
  • Cloning, Molecular
  • Computational Biology
  • Cotyledon / genetics
  • Cotyledon / metabolism
  • DNA Polymerase beta / genetics
  • DNA Polymerase beta / metabolism*
  • DNA Repair*
  • DNA, Plant / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genes, Reporter
  • Light*
  • Molecular Sequence Data
  • Nucleotide Motifs
  • Plant Extracts / genetics
  • Plant Extracts / metabolism
  • Plants, Genetically Modified / enzymology
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / growth & development
  • Plants, Genetically Modified / metabolism
  • Promoter Regions, Genetic*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods
  • Tobacco / genetics
  • Tobacco / metabolism


  • Arabidopsis Proteins
  • DNA, Plant
  • DNA-Binding Proteins
  • Plant Extracts
  • DNA polymerase beta2
  • DNA Polymerase beta