title: Functional analysis of light-regulated promoter region of AtPolλ gene.
abstract: 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.
authors.affiliation: Department of Chemistry, Bose Institute, 93/1, Acharya Prafulla Chandra Road, Kolkata, 700 009 West Bengal, India. sujitroy2006@gmail.com
authors.forename: Sujit
authors.initials: S
authors.lastname: Roy
authors.forename: Swarup Roy
authors.initials: SR
authors.lastname: Choudhury
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Singh
authors.forename: Kali Pada
authors.initials: KP
authors.lastname: Das
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D019295:Computational Biology; D018548:Cotyledon / Q000235:genetics / Q000378:metabolism; D019951:DNA Polymerase beta / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D018744:DNA, Plant / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D008027:Light; D008969:Molecular Sequence Data; D059372:Nucleotide Motifs; D010936:Plant Extracts / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D010936:Plant Extracts; C415367:DNA polymerase beta2; D019951:DNA Polymerase beta