Mechanism of REST/NRSF regulation of clustered protocadherin α genes

Repressor element-1 silencing transcription factor (REST) or neuron-restrictive silencer factor (NRSF) is a zinc-finger (ZF) containing transcriptional repressor that recognizes thousands of neuron-restrictive silencer elements (NRSEs) in mammalian genomes. How REST/NRSF regulates gene expression remains incompletely understood. Here, we investigate the binding pattern and regulation mechanism of REST/NRSF in the clustered protocadherin (PCDH) genes. We find that REST/NRSF directionally forms base-specific interactions with NRSEs via tandem ZFs in an anti-parallel manner but with striking conformational changes. In addition, REST/NRSF recruitment to the HS5-1 enhancer leads to the decrease of long-range enhancer-promoter interactions and downregulation of the clustered PCDH alpha genes. Thus, REST/NRSF represses PCDH alpha gene expression through directional binding to a repertoire of NRSEs within the distal enhancer and variable target genes.

Automated summary

REST/NRSF is a transcriptional repressor that recognizes NRSEs and regulates gene expression. It forms base-specific interactions with NRSEs via tandem ZFs in an anti-parallel manner, leading to downregulation of clustered PCDH alpha genes.