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Biology subjects

Francastel, C.

Publications and source records attributed to Francastel, C..

2 recordsLinked to original sources

ZBTB24 is a conserved multifaceted transcription factor at genes and centromeres that governs the DNA methylation state and expression of satellite repeats

Since its discovery as an Immunodeficiency with Centromeric instability and Facial anomalies syndrome-causative gene, ZBTB24 has emerged as a key player in DNA methylation, immunity and development. By extensively analyzing ZBTB24 genomic functions in ICF-relevant mouse and human cellular models, we revealed here its multiple facets as a transcription factor, with key roles in immune response-related genes expression and also in early embryonic development. Using a constitutive Zbtb24 ICF-like mutant and an auxin-inducible degron system in mouse embryonic stem cells, we showed that ZBTB24 is recruited to centromeric satellite DNA where it is required to establish the correct DNA methylation patterns through the recruitment of DNMT3B. Thus, our results further revealed an essential role for ZBTB24 at human and mouse centromeric satellite arrays, as a transcriptional repressor. Together, we unveiled unprecedented functions of ZBTB24 at human and mouse centromeres by directly controlling DNA methylation and transcription of the underlying tandem satellite repeats.

genomics↗

Tunable DNMT1 degradation reveals cooperation of DNMT1 and DNMT3B in regulating DNA methylation dynamics and genome organization

DNA methylation (DNAme) is a key epigenetic mark that regulates critical biological processes maintaining overall genome stability. Given its pleiotropic function, studies of DNAme dynamics are crucial, but currently available tools to interfere with DNAme have limitations and major cytotoxic side effects. Here, we present untransformed and cancer cell models that allow inducible and reversible global modulation of DNAme through DNMT1 depletion. By dynamically assessing the effects of induced passive demethylation through cell divisions at both the whole genome and locus-specific level, we reveal a cooperative activity between DNMT1 and DNMT3B to maintain and control DNAme. Moreover, we show that gradual loss of DNAme is accompanied by progressive and reversible changes in heterochromatin abundance, compartmentalization, and peripheral localization. DNA methylation loss coincided with a gradual reduction of cell fitness due to G1 arrest, but with minor level of mitotic failure. Altogether, this powerful system allows DNMT and DNA methylation studies with fine temporal resolution, which may help to reveal the etiologic link between DNA methylation dysfunction and human disease.

molecular biology↗