Nucleosome positioning in promoters is important for gene transcription regulation. In this paper, with a nucleosome prediction model, curvature profile, the characteristics of nucleosome positioning in promoters are ...Nucleosome positioning in promoters is important for gene transcription regulation. In this paper, with a nucleosome prediction model, curvature profile, the characteristics of nucleosome positioning in promoters are analyzed for miRNA genes and protein-coding genes. In the vicinity of transcription start site (TSS), there is a nucleosome-free region (NFR) followed by a positioned nucleosome at ～200 bp downstream of TSS. A similar characteristic is observed in independent intronic promoters and intergenic promoters, namely, both types of promoters have a longer NFR in 0—-400 bp upstream of TSS. Moreover, transcription factor binding sites (TFBSs) locate in the NFR with a high concentration. However, nucleosome pattern in dependent intronic promoters are like that in protein-coding promoters, with two nucleosomes positioned at -200—-400 bp and -400—-600 bp upstream of TSS. The results indicate nucleosome positioning is probably different in independent miRNA promoters and protein-coding promoters; and positioning seems to be an important factor not only in regulation of protein-coding gene, but also in that of miRNA gene.展开更多
基金supported by the National Natural Science Foundation of China (60671018 and 30800209)
文摘Nucleosome positioning in promoters is important for gene transcription regulation. In this paper, with a nucleosome prediction model, curvature profile, the characteristics of nucleosome positioning in promoters are analyzed for miRNA genes and protein-coding genes. In the vicinity of transcription start site (TSS), there is a nucleosome-free region (NFR) followed by a positioned nucleosome at ～200 bp downstream of TSS. A similar characteristic is observed in independent intronic promoters and intergenic promoters, namely, both types of promoters have a longer NFR in 0—-400 bp upstream of TSS. Moreover, transcription factor binding sites (TFBSs) locate in the NFR with a high concentration. However, nucleosome pattern in dependent intronic promoters are like that in protein-coding promoters, with two nucleosomes positioned at -200—-400 bp and -400—-600 bp upstream of TSS. The results indicate nucleosome positioning is probably different in independent miRNA promoters and protein-coding promoters; and positioning seems to be an important factor not only in regulation of protein-coding gene, but also in that of miRNA gene.
