title: Distinct role of core promoter architecture in regulation of light-mediated responses in plant genes.
abstract: In the present study, we selected four distinct classes of light-regulated promoters. The light-regulated promoters can be distinctly grouped into either TATA-box-containing or TATA-less (initiator-containing) promoters. Further, using either native promoters or their swapped versions of core promoter elements, we established that TATA-box and Inr (Initiator) elements have distinct mechanisms which are involved in light-mediated regulation, and these elements are not swappable. We identified that mutations in either functional TATA-box or Inr elements lead to the formation of nucleosomal structure. The nucleotide diversity in either the TATA-box or Inr element in Arabidopsis ecotypes proposes that the nucleotide variation in core promoters can alter the gene expression. We show that motif overrepresentation in light-activated promoters encompasses different specific regulatory motifs present downstream of TSS (transcription start site), and this might serve as a key factor in regulating light promoters which are parallel with these elements. Finally, we conclude that the TATA-box or Inr element does not act in isolation, but our results clearly suggests the probable involvement of other distinct core promoter elements in concurrence with the TATA-box or Inr element to impart selectivity to light-mediated transcription.
authors.affiliation: Plant Molecular Biology and Genetic Engineering Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow-226001 (U.P.), India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Srivastava
authors.forename: Krishan Mohan
authors.initials: KM
authors.lastname: Rai
authors.forename: Meenal
authors.initials: M
authors.lastname: Srivastava
authors.forename: Verandra
authors.initials: V
authors.lastname: Kumar
authors.forename: Bindu
authors.initials: B
authors.lastname: Pandey
authors.forename: Sudhir P
authors.initials: SP
authors.lastname: Singh
authors.forename: Sumit K
authors.initials: SK
authors.lastname: Bag
authors.forename: Brahma Deo
authors.initials: BD
authors.lastname: Singh
authors.forename: Rakesh
authors.initials: R
authors.lastname: Tuli
authors.forename: Samir V
authors.initials: SV
authors.lastname: Sawant
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D008027:Light; D009707:Nucleosomes / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D009707:Nucleosomes
keywords: TATA-box; cis-regulatory elements; initiator element; light; nucleosome; nucleotide polymorphism; transcription.