Project description:To study the function of Chd5 in neuronal differentiation, we cultured primary neural stem cells from WT and Chd5 deficient embryos.
Project description:CHD5 is frequently deleted in neuroblastoma, and appears to be a tumor suppressor gene; however, little is known about the role of CHD5. We found CHD5 mRNA was restricted to brain; by contrast most other remodeling ATPases were broadly expressed. CHD5 protein isolated from mouse brain was associated with HDAC2, p66, MTA3 and RbAp46 in a megadalton complex. CHD5 protein was detected in several rat brain regions and appeared to be enriched in neurons. CHD5 protein was predominantly nuclear in primary rat neurons and brain sections. Microarray analysis revealed genes that were upregulated and downregulated when CHD5 was depleted from primary neurons. CHD5 depletion altered expression of neuronal genes, transcription factors, and brain-specific subunits of the SWI/SNF remodeling enzyme. Aging and Alzheimers gene sets were strongly affected by CHD5 depletion from primary neurons. Chromatin immunoprecipitation revealed CHD5 bound to these genes, suggesting the regulation was direct. Together, these results indicate that CHD5 is found in a NuRD-like multi-protein complex. CHD5 is restricted to the brain, unlike the closely related family members CHD3 and CHD4. CHD5 regulates expression of neuronal genes, cell cycle genes and remodeling genes. CHD5 is linked to regulation of aging and Alzheimer’s genes.
Project description:The chromatin remodeler CHD5 is expressed in neural tissue and is frequently deleted in aggressive neuroblastoma. Very little is known about the function of CHD5 in the nervous system or its mechanism of action. Here we report that depletion of Chd5 in the developing murine neocortex blocks neuronal differentiation and leads to an accumulation of undifferentiated progenitors. CHD5 binds a large cohort of genes and is required for facilitating the activation of neuronal genes. It also binds a cohort of Polycomb targets and is required for the maintenance of H3K27me3 on these genes. Interestingly, the chromodomains of CHD5 directly bind H3K27me3 and are required for neuronal differentiation. In the absence of CHD5, a subgroup of Polycomb-repressed genes becomes aberrantly expressed. These findings provide new insights into the regulatory role of CHD5 during neurogenesis and suggest how inactivation of this candidate tumor suppressor might contribute to neuroblastoma. Examination of genome-wide binding/occupancy of CHD5 in the SH-SY5Y cell line
Project description:CHD5 is frequently deleted in neuroblastoma, and appears to be a tumor suppressor gene; however, little is known about the role of CHD5. We found CHD5 mRNA was restricted to brain; by contrast most other remodeling ATPases were broadly expressed. CHD5 protein isolated from mouse brain was associated with HDAC2, p66, MTA3 and RbAp46 in a megadalton complex. CHD5 protein was detected in several rat brain regions and appeared to be enriched in neurons. CHD5 protein was predominantly nuclear in primary rat neurons and brain sections. Microarray analysis revealed genes that were upregulated and downregulated when CHD5 was depleted from primary neurons. CHD5 depletion altered expression of neuronal genes, transcription factors, and brain-specific subunits of the SWI/SNF remodeling enzyme. Aging and Alzheimers gene sets were strongly affected by CHD5 depletion from primary neurons. Chromatin immunoprecipitation revealed CHD5 bound to these genes, suggesting the regulation was direct. Together, these results indicate that CHD5 is found in a NuRD-like multi-protein complex. CHD5 is restricted to the brain, unlike the closely related family members CHD3 and CHD4. CHD5 regulates expression of neuronal genes, cell cycle genes and remodeling genes. CHD5 is linked to regulation of aging and Alzheimer’s genes. CHD5 KD shRNA sequences were designed according to the instructions for the pLKO.1 system (Addgene). Control was as described (Sci307-1098,2005) Scramble, clone 1864 from Addgene). Virus was packaged using HEK-293T cells, pLKO.1 vector with shRNA inserts for CHD5, and the control. 48 hours after transfection of 293 cells, medium containing virus was filtered (0.45 micron), then applied for 6 hours to primary cortical neurons one day after the neurons were plated (Day 1). Medium was removed, and replaced with Neural Basal Medium, and the cells were cultured until Day 5, 9 or 12. RNA was harvested from 3 replicates of the treated primary cortical neurons at each time point. RNA was isolated using RNAeasy Kit (Qiagen), Quality and quantity of the total RNA was checked with the Agilent 2100 bioanalyzer using RNA 6000 Nano chips. RNA was labeled using the standard Illumina protocol and Illumina TotalPrep RNA Amplification Kit (Ambion; Austin, TX, cat # IL1791) Biotin labeled cRNA was hybridized to Illumina's Sentrix Rat Ref-12 v1 Expression BeadChips.
Project description:The chromatin remodeler CHD5 is expressed in neural tissue and is frequently deleted in aggressive neuroblastoma. Very little is known about the function of CHD5 in the nervous system or its mechanism of action. Here we report that depletion of Chd5 in the developing murine neocortex blocks neuronal differentiation and leads to an accumulation of undifferentiated progenitors. CHD5 binds a large cohort of genes and is required for facilitating the activation of neuronal genes. It also binds a cohort of Polycomb targets and is required for the maintenance of H3K27me3 on these genes. Interestingly, the chromodomains of CHD5 directly bind H3K27me3 and are required for neuronal differentiation. In the absence of CHD5, a subgroup of Polycomb-repressed genes becomes aberrantly expressed. These findings provide new insights into the regulatory role of CHD5 during neurogenesis and suggest how inactivation of this candidate tumor suppressor might contribute to neuroblastoma.
Project description:To search for factors regulating neuronal differentiation, we performed a genome-wide loss-of-function CRISPR/Cas9 screen in haploid human ESCs. The regulators were identified by the quantification of depletion of their mutant clones within a pooled loss-of-function library upon neuronal differentiation.
Project description:Gene duplication enables the emergence of new functions by lowering the general evolutionary pressure. Previous studies have highlighted the role of specific paralog genes during cell differentiation, e.g., in chromatin remodeling complexes. It remains unexplored whether similar mechanisms extend to other biological functions and whether the regulation of paralog genes is conserved across species. Here, we analyze the expression of paralogs across human tissues, during development and neuronal differentiation in fish, rodents and humans. While ~80% of paralog genes are co-regulated, a subset of paralogs shows divergent expression profiles, contributing to variability of protein complexes. We identify 78 substitutions of paralog eggNOG pairs that occur during neuronal differentiation and are conserved across species. Among these, we highlight a substitution between the paralogs Sec23a and Sec23b subunits of the COPII complex. Altering the ratio between these two genes via silencing-RNA knockdown was able to influence neuronal differentiation in different ways. We propose that remodeling of the vesicular transport system via paralog substitutions is an evolutionary conserved mechanism enabling neuronal differentiation.
Project description:Gene duplication enables the emergence of new functions by lowering the general evolutionary pressure. Previous studies have highlighted the role of specific paralog genes during cell differentiation, e.g., in chromatin remodeling complexes. It remains unexplored whether similar mechanisms extend to other biological functions and whether the regulation of paralog genes is conserved across species. Here, we analyze the expression of paralogs across human tissues, during development and neuronal differentiation in fish, rodents and humans. While ~80% of paralog genes are co-regulated, a subset of paralogs shows divergent expression profiles, contributing to variability of protein complexes. We identify 78 substitutions of paralog eggNOG pairs that occur during neuronal differentiation and are conserved across species. Among these, we highlight a substitution between the paralogs Sec23a and Sec23b subunits of the COPII complex. Altering the ratio between these two genes via silencing-RNA knockdown was able to influence neuronal differentiation in different ways. We propose that remodeling of the vesicular transport system via paralog substitutions is an evolutionary conserved mechanism enabling neuronal differentiation.