A Model of Transcriptional Activation of DNA by Loosening of Chromatin Structure

As a model of transcriptional activation of DNA by loosening of chromatin structure, we have developed a polymeric complex of plasmid DNA and a cationic polymer (SRC-Y) bearing peptide moieties that are phosphorylatable by p60c-Src. After phosphorylation, the diffusion constant of DAPI-intercalated plasmid DNA in SRC-Y/DNA particles increased, concomitantly with initiation of transcription, meaning that the access of preinitiation complex, which recruits RNA polymerase II to promoter sequences, to chromatin-packaged DNA for transcriptional initiation is governed by DNA strand mobility.

Automated summary

This study demonstrates that by increasing the mobility of DNA strands, the preinitiation complex can better access chromatin-packaged DNA for transcriptional initiation.