Thanks a lot Filip, the perspective was really a wonderful surprise!

oops: a novel protein complex*

& blueskyless: Erica De Zan, Guizela Huelsz-Prince, Marleen Dekker, Alex Fish, Lona Kroese, Simon Linder, Miguel Hermandez-Quiles, Ji-Ying Song, Lodewyk Wessels, Sebastian Nijman 11/11

Thanks to all coauthors: @rborza.bsky.social @sgregoricchio.bsky.social @amazouzi.bsky.social @zwartlab.bsky.social @lindersimon.bsky.social @tassosperrakis.bsky.social @thijnbrummel.bsky.social

Please check the paper for more experiments and interesting findings and stay tuned, as I am convinced this fascinating complex will be connected to much more interesting biology in the future. 10/11

I'm truly excited to share this work with you today. Unraveling this fascinating complex was a rewarding challenge, made possible by the incredible teamwork behind it. I'm deeply grateful to all the brilliant collaborators who contributed their insights and energy to make this possible. 9/11

1) Zincore recognises the highly conserved ZNF fold, explaining its broad ZNF recognition, and 2) Zincore locks the ZNF onto DNA, stabilizing promoter binding. Revealing an entirely new mode of how ZNFs activate transcription. 8/11

CryoEM analysis of the Zincore bound to ZFP91 onto the DNA revealed a striking complex: instead of recognising an effector domain, Zincore binds to multiple DNA-bound ZNF domains directly, which revealed two peculiarities: 7/11 @rborza.bsky.social @tassosperrakis.bsky.social

Additionally, in vitro binding experiments demonstrated direct binding of Zincore to ZNFs on DNA. This depended on SEPHS1 Arg371, a residue which is mutated in patients with a neurodevelopment syndrome, and turned out to be critical for transcriptional activation. 6/11

Additional searches revealed different transcription factors to bring Zincore to chromatin: coincidentally all zinc finger transcription factors? 5/11

Using haploid genetics in this reporter cell line identified ZFP91, a zinc finger transcription factor, as Zincore partner. ChIP-seq showed Zincore is directly involved in gene expression via recruitment to chromatin by ZFP91, though this explains only a fraction of Zincore promoter binding. 4/11

As a PhD student, this was challenging. I worked on an uncharacterized protein complex, yet had no idea how it worked. RNAseq showed many genes were activated by QRICH1 and SEPHS1, but how? This gave us options! We made a reporter in one of Zincore's activated genes: GHDC. 3/11

From analysing haploid genetic screens carried out by our group for different phenotypes we found that QRICH1 and SEPHS1 affect phenotypes similarly. They form a complex that we name Zincore. 2/11