lncRNA transcriptional initiation induces chromatin remodeling within a limited range in the fission yeast fbp1 promoter.

ABSTRACT

Long noncoding RNAs (lncRNAs) transcribed across gene promoters have been detected. These regulate transcription by mechanisms that have not been fully elucidated. We herein show that the chromatin configuration is altered into an accessible state within 290 bp downstream from the initiation site of metabolic-stress-induced lncRNAs (mlonRNAs) in the promoter of the fission yeast fbp1 gene, whose transcription is massively induced upon glucose starvation. Chromatin upstream from fbp1 is progressively altered into an open configuration, as a cascade of transcription of three overlapping mlonRNA species (-a, -b and -c in order) occurs with transcriptional initiation sites progressing 5' to 3' upstream of the fbp1 promoter. Initiation of the shortest mlonRNA (mlonRNA-c) induces chromatin remodeling around a transcription factor-binding site and subsequent massive induction of fbp1. We identify the cis-element required for mlonRNA-c initiation, and by changing the distance between mlonRNA-initiation site and the transcription factor-binding site, we show that mlonRNA-initiation effectively induces chromatin remodeling in a limited distance within 290 bp. These results indicate that mlonRNAs are transcribed across the fbp1 promoter as a short-range inducer for local chromatin alterations, and suggest that strict chromatin modulation is archived via stepwise mlonRNA-initiations.