bioRxiv Science⌕ Search

Biology subjects

Vukic, M.

Publications and source records attributed to Vukic, M..

3 recordsLinked to original sources

The epigenetic reader MORC3 is required for T cell development in the thymus

Cell fate decisions are orchestrated by an interplay of epigenetic factors in collaboration with transcriptional activators and repressors. The epigenetic reader MORC3 is known as a silencer of endogenous retroviruses in mouse embryonic stem cells. Here, we show that mouse MORC3 is expressed in the thymus and reveal that MORC3 loss of function leads to a severe arrest in T cell development at the DN1 stage, accompanied by an expansion of natural killer and myeloid cells. MORC3 function in thymus depends on its ATPase and its ability to bind H3K4me via the CW-type zinc finger domain. We find altered chromatin accessibility at regulatory elements of key T cell transcription factors in DN1 cells and show that re-expressing TCF1 in MORC3-deficient progenitor cells, rescues T cell development. Our work indicates a novel function for MORC3 in modulating regulatory sites essential for T cell lineage commitment at the level of chromatin.

genetics↗

Identification of SENP7 and UTF1/VENTX as new loci influencing clusteredprotocadherin methylation across blood and brain using a genome-wide associationstudy

The epigenetic regulation of clustered protocadherin (cPCDH) genes is tightly linked to their function as specific cell surface barcodes for neural self-nonself discrimination. Differential cPCDH DNA methylation in both blood and brain has been implicated in diverse human traits and diseases ranging from BMI, aging, cancer and brain disorders. However, the unique regulation of cPCDH methylation remains poorly understood. Therefore, we performed a genome-wide association study to evaluate the association of >7 million genetic variants with DNA methylation at 607 cPCDH CpGs measured in whole blood of 3777 individuals and validated findings in prefrontal cortex samples obtained from 523 brain donors. We observed concordant cPCDH methylation patterns in blood and prefrontal cortex, which switched between hypo-, intermediate and hypermethylation over short distances with the former overlapping with the promoter regions of each cPCDH member. Through methylation quantitative trait locus (meQTL) analysis in trans, we first confirmed the broad effect of the candidate gene SMCHD1 on cPCDH methylation in blood which validated in prefrontal cortex. Through a genome-wide analysis, we next identified the SENP7 and UTF1/VENTX loci to have widespread, subcluster-specific effects on cPCDH methylation in blood which was validated in prefrontal cortex. While SENP7 can indirectly affect DNA methylation through the deSUMOylation of the chromatin repressor KAP1, UTF1 and VENTX are two genes involved in embryonic development not previously implicated in epigenetic regulation. Our findings shed new light on the processes involved in cPCDH methylation that may underlie associations with disease.

genetics↗

Zbtb24 binding protects promoter activity by antagonizing DNA methylation in mESCs

DNA methylation is a key epigenetic modification essential for normal development. How particular factors control DNA methylation patterns and activity of a given locus is incompletely understood. The zinc finger protein Zbtb24 has been implicated in transcriptional activation/repression and the DNA methylation maintenance pathway. Here, using whole genome bisulfite sequencing in mouse embryonic stem cells, we report that besides a general trend towards DNA hypomethylation, many genomic sites gain methylation in the absence of Zbtb24 and they include promoters of actively transcribed genes. DNA hypomethylation is not generally associated with gene expression changes, suggesting that additional epigenetic safeguards are in place that ensure silencing of the affected loci. Remarkably, we identify a set of genes that is particularly susceptible to Zbtb24 occupancy. At these sites, Zbtb24 binding is not only required for gene activity but also required for maintaining the unmethylated state of the promoter.

molecular biology↗