Krzysztof Herka
@kherka.bsky.social
66 followers 180 following 16 posts
PhD student, Balasubramanian lab, Cancer Research UK - Cambridge Institute (@cruk-ci.bsky.social)
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kherka.bsky.social
How does (local #DNA) structure affect (3D #genome) structure? Can mutating G4s abolish #enhancers key for #blood function?

In the second part of our explorations of #G4s in gene regulation, we show how abolishing G-quadruplex structures in the genome disrupts enhancers. 1/9
doi.org/10.1186/s130...
DNA G-quadruplex structures act as functional elements in α- and β-globin enhancers - Genome Biology
Background Enhancer elements interact with target genes at a distance to modulate their expression, but the molecular details of enhancer–promoter interaction are incompletely understood. G-quadruplex...
doi.org
kherka.bsky.social
Lots of exciting chromatin biology - and great recaps!
triggerloop.bsky.social
Eva Nogales @nogaleslab.bsky.social introducing the 2025 CSH Mechanisms of Eukaryotic Transcription Meeting. Co-organizing with Wendy Bickmore @wbickmor.bsky.social and Joanna Wysocka. Will intermittently try to update as allowed
Reposted by Krzysztof Herka
cruk-ci.bsky.social
Beyond carrying out vital research, our staff are involved in lots of science outreach activities every year.

Recently, we hosted pupils for our annual Careers Lab. This programme is designed to inspire the next generation of STEM scientists & supporters.

More: www.cruk.cam.ac.uk/students/car...
kherka.bsky.social
Many thanks especially to Colm Doyle (now at @embl.org), who began this work with his beta globin locus study and @seanflynn.bsky.social (now of sites.google.com/view/flynnlab/ at @exeter.ac.uk - great things to come) for an incredible journey, as well as all authors at @cruk-ci.bsky.social! 9/9
Flynn Lab
FLYNNLAB Chromatin biology
sites.google.com
kherka.bsky.social
....then edited them out to show how the regulation of genes in 3D contact was affected. 8/9
kherka.bsky.social
How do G4s function at enhancers? In our #proteomics pulldowns, RNA polymerase II subunits were enriched, together with known G4 binding proteins - but not some common architectural factors (e.g. YY1, CTCF) - we confirmed that some RNAPII subunits specifically bind G4s (Fig. 4A, F). 6/9
kherka.bsky.social
For the beta HS2 enhancer, this effect is masked by hyper activation of the neighbouring enhancer, HS3 - removing HS3 unveils a similar effect (Figure 3A-D for alpha, Figure 3E-H for beta). 4/9
kherka.bsky.social
What happened? In the alpha HS-40 enhancer, such a mutation (seven G-to-T mutations) was sufficient to reduce globin gene expression to levels observed when the whole enhancer region (of around 350 bases) is deleted. Enhancer-promoter contacts and local #chromatin accessibility is also reduced. 3/9
We found a G4 in HS-40, the dominant enhancer of the alpha-globin locus regulatory region, replaced it with a sequence that can no longer form a G4; cognate gene expression, chromatin accessibility, and enhancer-promoter contacts were reduced. We then introduced a different G4-forming sequence - enhancer activity was restored.
kherka.bsky.social
Using the classic #globin #superenhancer systems, we discovered two G4 structures in dominant enhancers in both the alpha globin and beta globin locus control systems - and replaced them with non-G4-forming sequences using CRISPR. 2/9
kherka.bsky.social
How does (local #DNA) structure affect (3D #genome) structure? Can mutating G4s abolish #enhancers key for #blood function?

In the second part of our explorations of #G4s in gene regulation, we show how abolishing G-quadruplex structures in the genome disrupts enhancers. 1/9
doi.org/10.1186/s130...
DNA G-quadruplex structures act as functional elements in α- and β-globin enhancers - Genome Biology
Background Enhancer elements interact with target genes at a distance to modulate their expression, but the molecular details of enhancer–promoter interaction are incompletely understood. G-quadruplex...
doi.org
Reposted by Krzysztof Herka
gensocuk.bsky.social
We heard about "Alternative DNA structures in enhancer-promoter communication" from @seanflynn.bsky.social from @uniofexeter.bsky.social #Epigenetics2025

@uniofexeternews.bsky.social
Reposted by Krzysztof Herka
cruk-ci.bsky.social
🚨 We’re Hiring!🚨

Passionate about cancer research? Join Madzia Crossley's team to investigate how R-loop dysregulation contributes to cancer.

We have two exciting opportunities:
Research Associate: jobs.cam.ac.uk/job/50675/
Senior Scientific Associate: jobs.cam.ac.uk/job/50689/
kherka.bsky.social
A great opportunity to work on #epigenetics, #genetics and gene regulation in #neuroscience with an inspirational young PI - please share and apply!
seanflynn.bsky.social
We have a funded PhD position available in Exeter @exeter.ac.uk
Gene Regulation in Brain Development and Disease 🧬
Please share / repost

www.exeter.ac.uk/study/fundin...
Award details | Funding and scholarships for students | University of Exeter
www.exeter.ac.uk
Reposted by Krzysztof Herka
cruk-ci.bsky.social
Congratulations to @isabelesain.bsky.social, who is awarded the 2024 CRUK Cambridge Institute PhD Thesis Prize.

In her doctoral research, Bel discovered a new molecular mechanism in cancer gene regulation opening up a new therapeutic window for cancer treatments.

www.cruk.cam.ac.uk/news/bel-esa...
Dr Isabel Esain Garcia receives Cancer Research UK Cambridge Institute 2024 PhD Thesis Prize
kherka.bsky.social
A great #PhD opportunity for anyone interested in #epigenetics in #neurons and the broader context of #neuroscience - having worked with @seanflynn.bsky.social and Jack, they are brilliant choices for mentors!
seanflynn.bsky.social
If you are interested in #Epigenetics apply for a PhD with Jack Hardwick and Jonathan Hanley in Bristol, and our group in Exeter.

Elucidating the role of DNA modifications in neurons
Funded by #SWBio DTP
Deadline: Dec 4
To apply: www.swbio.ac.uk/programme/ho...
kherka.bsky.social
Thank you @seanflynn.bsky.social - looking forward to sharing science (mostly #epigenetics, #G4, gene regulation and #chromatin) with everyone, especially great work from the Flynn Lab!