Project description:R-loops are three-stranded nucleic acid structures consisting of a DNA-RNA hybrid and a displaced single-stranded DNA (ssDNA). R-loops are facilitators of gene expression and genome stability that play both regulatory and potentially deleterious roles in cells. To elucidate the protein-based mechanisms of R-loop regulation, we developed an APEX-based proximity proteomics using a catalytically inactive mutant of RNase H1 (APEX-RNH1D210N) to profile the proximal proteome of R-loops in cells. Our proteomics results identified a list of known and potential R-loop-binding proteins with diverse molecular functions, and confirmed YY1 as a novel R-loop-binding protein through a series of in-vitro binding assays. YY1 is a DNA-binding protein recognizing a consensus motif or G-quadruplex (G4) structure. Our binding results indicated YY1's notably stronger affinity for R-loops compared to RNA/DNA hybrid, DNA G4 and DNA without a consensus motif, implying R-loops' role in YY1 recruitment to genomic regions lacking a YY1-binding motif. To investigate YY1-R-loop interaction in cells, we introduced R-loop structures into specific genomic regions vis CRISPR-dCas9 targeting, followed by DRIP-qPCR, YY1-ChIP-qPCR and RT-qPCR experiments. Increased R-loop levels corresponded with heightened YY1 occupancy and differential gene expression, suggesting YY1-R-loop interactions contribute to transcriptional regulation. More importantly, our RNA-seq and YY1-ChIP-seq results revealed that the interactions between YY1 and promoter R-loops were involved in global transcriptional regulation, especially in the positive regulation of transcription. Together, we identified YY1 as a novel R-loop-binding protein and uncovered a mechanism wherein YY1-R-loop interactions regulate gene expression.
Project description:We mesured YY1 binding in isolated mouse crypt epihtelium using ChIP-seq Jejunal crypt epithelia were isolated and processed for ChIP using YY1 antibody Santa Cruz, SC-1703, lot E0511
Project description:Here we performed a ChIP-seq experiment for Zeb1 trancription factor on a sample of adherent cultures of human neural stem cells (Cb192 cell line) and of a human glioblastoma cancer stem-like cell line (NCH421k). The result is the generation of the genome-wide maps for Zeb1 binding to chromatin in human neural stem cells and glioblastoma stem-like cells.
Project description:This SuperSeries is composed of the following subset Series: GSE31784: Expression changes in Yy1 knock down mouse embryonic stem cells GSE31785: Yy1 occupancy of mouse ES cell genome Refer to individual Series
