@article{165ff195a0f54ca7baccfd54a2d2f698,
title = "Hierarchical reactivation of transcription during mitosis-to-G1 transition by Brn2 and Ascl1 in neural stem cells",
abstract = "During mitosis, chromatin condensation is accompanied by a global arrest of transcription. Recent studies suggest transcriptional reactivation upon mitotic exit occurs in temporally coordinatedwaves, but the underlying regulatory principles have yet to be elucidated. In particular, the contribution of sequence-specific transcription factors (TFs) remains poorly understood. Here we report that Brn2, an important regulator of neural stem cell identity, associates with condensed chromatin throughout cell division, as assessed by live-cell imaging of proliferating neural stem cells. In contrast, the neuronal fate determinant Ascl1 dissociates from mitotic chromosomes. ChIP-seq analysis reveals that Brn2 mitotic chromosome binding does not result in sequence-specific interactions prior to mitotic exit, relying mostly on electrostatic forces. Nevertheless, surveying active transcription using single-molecule RNAFISH against immature transcripts reveals differential reactivation kinetics for key targets of Brn2 and Ascl1, with transcription onset detected in early (anaphase) versus late (early G1) phases, respectively. Moreover, by using a mitotic-specific dominant-negative approach, we show that competing with Brn2 binding during mitotic exit reduces the transcription of its target gene Nestin. Our study shows an important role for differential binding of TFs to mitotic chromosomes, governed by their electrostatic properties, in defining the temporal order of transcriptional reactivation during mitosis-to-G1 transition.",
keywords = "Ascl1, Brn2, M-G1 transition, Mitotic bookmarking, Neural stem cell, Transcription",
author = "Soares, {M{\'a}rio A. F.} and Soares, {Diogo S.} and Vera Teixeira and Abeer Heskol and Bressan, {Raul Bardini} and Pollard, {Steven M.} and Oliveira, {Raquel A.} and Castro, {Diogo S.}",
note = "Funding Information: We thank Michael Wegner for providing the Oct6-GFP, DBD (Oct6)-eGFP, and DBD (Brn4)-eGFP plasmids. We thank the technical support of Instituto Gulbenkian de Ci{\^e}ncia{\textquoteright}s (IGC) Advanced Imaging Facility (AIF-UIC), which is supported by the national Portuguese funding (PPBI-POCI-01-0145-FEDER-022122), cofinanced by Lisboa Regional Operational Programme (Lisboa 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) and Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia (FCT; Portugal). In particular, we thank Nuno Pimp{\~a}o and Gabriel Martins for excellent assistance with imaging acquisition and data analysis. We thank the IGC Genomics Facility for guidance with library synthesis and NGS and the IGC Flow Cytometry Facility. We also acknowledge the support of i3S Scientific Platform Advanced Light Microscopy, member of the national infrastructure PPBI-Portuguese Platform of BioImaging (supported by POCI-01-0145-FEDER-022122). In particular, we thank Maria Azevedo for excellent assistance. This work was funded by FCT grant PTDC/BIA-BID/29663/2017 to D.S.C., a FCT doctoral fellowship PD/BD/105999/2014 to M.A.F.S., an EMBO installation grant IG2778 to R.A.O., and CEE-Cind from FCT (CEECIND/01092/2017) to R.A.O. Publisher Copyright: {\textcopyright} 2021 Soares et al.",
year = "2021",
month = jul,
day = "1",
doi = "10.1101/GAD.348174.120",
language = "English",
volume = "35",
pages = "1020--1034",
journal = "Genes & development",
issn = "0890-9369",
publisher = "Cold Spring Harbor Laboratory Press",
number = "13",
}