Project description:In this study we used mice lacking Evf2 (Evf2TS/TS) and mice expressing a truncated form of Evf2 (Evf1TS/TS) to determine UCE lncRNA epigenetic and chromosome toplogical control. We used 4Cseq to investigate how Evf2 regulates UCE interactions along chromosome 6 (where Evf2 is expressed). We used ChIpseq to compare histone methylation profiles from Evf2TS/TS and Evf1TS/TS. In addition, we used ChIPseq to determine Evf2-depedent regulation of cohesin subunit binding (SMC1 and SMC3) and histone H3K27acetylation. Together, these data support that Evf2 UCE lncRNA controls chromosome topology over multi-megabse distances, through cohesin binding and effects on histone methylation and acetylation. Also included is the ChIPseq profile of Dlx binding sites in SW (outbred strain of mice) from E13.5 GE.
Project description:Cullin-RING ubiquitin ligases (CRLs) control the degradation of a wide landscape of human proteins in combination with ubiquitin-carrying enzymes (UCEs). CRL expansion during evolution is apparent, with a few dozen in yeast that function with a single UCE and as many as 300 in humans that function with at least 8 UCEs. A major unaddressed question is why human CRL buildup has been accompanied by additional UCEs that function with CRLs. Here we demonstrate that human CRLs and UCEs can display specificity, resulting in increased affinity for each other and enhanced rates of ubiquitin transfer to substrates. To uncover the structural basis for CRL-UCE specificity, cryo-EM was performed on a CRL2 subfamily member with substrate receptor subunit FEM1C (CRL2FEM1C) in complex with a proxy for catalytically active UCE. The structure elucidated an extensive CRL-UCE interface that promotes proximity between the UCE active site and CRL2FEM1C-bound substrate. Unanticipated selectivity was also observed between the CRL substrate Lys ubiquitylation sites and the identity of the UCE. CRL-UCE specificity also manifests during targeted protein degradation by affecting the activities of drugs that induce ubiquitylation of neosubstrates. An emerging CRL code is revealed that drives selective formation of CRL-UCE complexes to promote rapid substrate ubiquitylation.
Project description:We perform a self hybridisation comprative genomic hybridization (CGH) in order to validate the probe tiling design we done on Trichoderma reesei. This hybridization was done using QM6a wild type strain.
Project description:Non-coding regulatory elements (NCRE) represent a major fraction of the human genome, play important roles in different biological pathways, and have the potential as genomic medicine targets. We developed a straightforward dual-CRISPR screening system capable of deleting thousands of NCREs genome-wide to study their functions in distinct biological contexts in K562 cells and 293T cells. We show that many NCREs, including ultraconserved elements (UCE), have silencer activity and play essential roles in cell growth and drug response. NCREs with redundant functions could also be identified from the screening data. This dual-CRISPR system is also compatible with single-cell sequencing. We identified that UCE PAX6_Tarzan might be critical in heart development, as removing it from human embryonic stem cells led to defects in cardiomyocyte differentiation. Our study provides further evidence that many NCREs have important biological functions contributing to human biology and diseases, and may serve as future drug targets.
