Tobias Williams

@tobiaswilliams.bsky.social

Post doc at @FMIscience in the Chao lab | formerly @PeterMacCC | Views are my own

The heatwave is finally over - just in time for our “Frosty Foci” to finally come online! ❄️🦠 We found that E. coli builds a transient nucleolus-like ribosome biogenesis compartment during cold adaptation, when RNA (mis)folding makes ribosome biogenesis challenging.

And mRNPs are not simply cargo. Super-resolution imaging reveals SON/SRRM2 scaffold networks that organize retained mRNPs and remodel with mRNP load, suggesting that nuclear speckle architecture is tightly coupled to this layer of mRNP quality control.

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🧵 New preprint! How does a chromatin remodeler know where to act? In our latest study, we show how the transcription factor ADNP targets CHD4 remodeling activity to silence transposons and block CTCF. 👇 A thread on the ChAHP complex and how it weaves chromatin 🧬🔬🧵 www.biorxiv.org/content/10.1...

Remodeling Activity of ChAHP Restricts Transcription Factor Access to Chromatin

Transcription in eukaryotes is regulated by chromatin-based mechanisms that control nucleosome occupancy, chromatin modifications, and transcription factor binding. We have previously shown that the transcription factor ADNP forms the ChAHP complex with the chromatin remodeler CHD4 and HP1 proteins, acting as a site-specific regulator of transcription and antagonist of CTCF binding. However, the molecular basis of these functions remained unclear. Here, we demonstrate that the CHD4 subunit is essential to antagonize CTCF and silence transcription of transposons, while HP1 proteins are dispensable. Although the remodeling activity of CHD4 is not required for ChAHP chromatin association, it is critical for both transposon repression and CTCF antagonism. Our findings support a model wherein ADNP recruits chromatin remodeling activity in a sequence-specific manner, enabling transcriptional control and local modulation of chromatin architecture. ### Competing Interest Statement The Friedrich Miescher Institute for Biomedical Research (FMI) receives significant financial contributions from the Novartis Research Foundation. Published research reagents from the FMI are shared with the academic community under a Material Transfer Agreement (MTA) having terms and conditions corresponding to those of the UBMTA (Uniform Biological Material Transfer Agreement). Novartis Research Foundation, n.a. Swiss National Science Foundation, grant 310030_188835

biorxiv.org