Chromatin distribution alterations of histone modifacations and PRC2 complex caused by Rack7 deletion in primary astrocyte [ChIP-Seq]

Dysregulation of epigenetic mechanisms play crucial roles in brain development and disease. Emerging evidence suggests that RACK7, an epigenetic reader protein, may play a role in brain development, but in vivo exploration of RACK7 in neural development and the underlying mechanisms are still lacking. Here, we established a conditional knock-out Rack7 mouse model and show that Rack7-deficient mice exhibit overt developmental defects. Multicomplex immunofluorescence staining (mIF) of cell-type specific markers indicates that the developmental defects are associated with compromised astrocyte development. Mechanistically, we surprisingly found RACK7 interacts with PRC2 complex, which acts as the histone H3K27 methyltransferase. Our results suggest RACK7 binding with PRC2 complex helps to establish the proper genomic location of histone H3K27me3 modification. Deletion of Rack7 in astrocyte leads to a remarkable decrease of H3K27me3 chromatin enrichment. genome-wide?. Functionally, we found RACK7 works together with H3K27me3 to prevent overactivation of Wnt signaling pathway and other astrocyte differentiation genes. Collectively, our study provides new insights into the cellular and molecular mechanisms underlying brain development regulated by RACK7. To gain insight into the molecular mechanisms underlying Rack7 function in astrocytes, we performed chromatin immunoprecipitation coupled with deep sequencing (ChIP-seq) to analyze the chromatin distribution of histone modifations related to Rack7,including enhancer marker (H3K4me1/H3K27ac), H3K4me3, and H3K27me3. We also analyzed the genome occupancy of PRC2 complex using ChIP-seq in primary astrocyte, which acts as the histone H3K27 methyltransferase.