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Henri Niskanen

@henriniskanen

Postdoc @ Hnisz lab | Max Planck Institute for Molecule Genetics, Berlin | Condensates & Gene regulation | Past: PhD (Molecular Medicine, Uni. East Finland) MSc (biochemistry, Uni. Turku)

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01.12.2024
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Latest posts by Henri Niskanen @henriniskanen

Redirecting

Our most recent work on the “function and evolution” of #nuclear-speckles is now online at Cell @cp-cell.bsky.social
doi.org/10.1016/j.ce...
Read the thread👇 for the highlights of our findings.

25.02.2026 16:01 👍 122 🔁 60 💬 9 📌 5

I’m thrilled to share that my PhD work has been just published in Cell. After a long and bumpy ride, we uncovered the core function of nuclear speckles -splicing of GC-levelled exons- and traced the evolution of this gene architecture and condensates themselves to amniotes.

25.02.2026 16:53 👍 71 🔁 19 💬 0 📌 2
Preview
Transcriptional and post-transcriptional regulation of transposable elements and their roles in development and disease - Nature Reviews Molecular Cell Biology Transposable elements (TEs) comprise nearly half of the human genome. This Review discusses transcriptional and post-transcriptional mechanisms that repress TE activity, how TEs escape this suppressio...

We wrote a review on Transposable Elements (TEs) and almost all aspects of TE silencing and their roles in biological processes & disease.
www.nature.com/articles/s41...

30.06.2025 13:11 👍 142 🔁 69 💬 2 📌 3
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⚠️ I am really excited to share the work of Anastasios Balaskas, an excellent PhD candidate in the lab, with the wider world. Tasos made a significant advance: generating a stem cell-based embryo model that contains both posterior and anterior neural tissues of the late-stage gastrulating embryo.

23.06.2025 07:51 👍 124 🔁 45 💬 4 📌 7
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This is a piece that I and @karsten-rippe.bsky.social discussing a lot, and a topic that is very close to my heart. The editors @naturerevgenet.bsky.social gave us the stage to do so, and the final version of our review is now available under this link: rdcu.be/erP1u

A short thread follows 1/n

19.06.2025 16:37 👍 95 🔁 39 💬 3 📌 2
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‘Killswitch’ protein lets scientists study immobilized cellular droplets Synthetic peptide fixes biomolecular condensates, revealing how these enigmatic cell structures actually work.

Check out a technology feature in @nature.com by Elie Dolgin regarding our recent 'Killswitch' publication
www.nature.com/articles/d41...

Thank you for the comments and first impressions by Rick Young, Isaac Klein, @danfengcai.bsky.social @superscijew.bsky.social
@yaotianzhang.bsky.social

17.06.2025 19:43 👍 9 🔁 3 💬 0 📌 0
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Probing condensate microenvironments with a micropeptide killswitch - Nature Targeting a non-natural micropeptide ‘killswitch’ to several biomolecular condensates altered condensate compositions and revealed condensate functions in human cells

Nature research paper: Probing condensate microenvironments with a micropeptide killswitch

https://go.nature.com/4mMlGyc

09.06.2025 12:34 👍 19 🔁 6 💬 0 📌 0

Work is a collaboration with @matthewkraushar.bsky.social, @aktast.bsky.social and the MPIMG Service Groups FACS, microscopy, sequencing and mass spec, as well as researchers from Austria, the US and Switzerland. Link to the publication:
www.nature.com/articles/s41...

06.06.2025 08:29 👍 3 🔁 2 💬 0 📌 0
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In @nature.com Yaotian Zhang and @henriniskanen.bsky.social from the Hnisz Lab discovered a micropeptide, the "Killswitch," which alters the physical state of biomolecules in condensates. This tool solidifies dynamic, liquid-like droplets, affecting their function.
--> www.molgen.mpg.de/4884827

06.06.2025 08:27 👍 21 🔁 6 💬 1 📌 0
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Probing condensate microenvironments with a micropeptide killswitch - Nature Targeting a non-natural micropeptide ‘killswitch’ to several biomolecular condensates altered condensate compositions and revealed condensate functions in human cells

A bottleneck for studying the biological function of biomolecular condensates is unavailability of tools to selectively probe them within living cells. @nature, researchers report one such tool, showcasing its use in various contexts including disease. www.nature.com/articles/s41...

05.06.2025 09:02 👍 3 🔁 1 💬 0 📌 0
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7/7
In summary, the killswitch is a versatile tool that alters condensate material properties in live cells. It revealed that condensate composition and functions rely on their microenvironments, paving the way for new biology and therapeutic strategies

04.06.2025 15:29 👍 1 🔁 0 💬 0 📌 0

6/7
In zebrafish embryos, killswitch targeted to transcriptional condensates via NANOG suppressed miRNA transcription. Across models, killswitch reveals functional consequences of changing condensate material property, without dissolving the structures themselves.

04.06.2025 15:29 👍 1 🔁 0 💬 1 📌 0

5/7
In adenoviral 52K condensates, killswitch reduced dynamics and blocked recruitment of capsid protein IIIa, despite preserved binding interfaces. Viral progeny production dropped >90%. The KS thus uncovers hidden roles of condensate microenvironments for condensate regulation.

04.06.2025 15:29 👍 0 🔁 0 💬 1 📌 0

4/7
Targeting BRD4::NUT condensates with killswitch disrupted RNA Pol II partitioning and reduced transcription. In NUP98::KDM5A-driven AML cells, killswitch caused proteasome-mediated degradation of fusion condensates and impaired leukemia cell growth.

04.06.2025 15:29 👍 0 🔁 0 💬 1 📌 0
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3/7
To analyze compositional changes, we developed NuFANCI, a FACS-based method to isolate nuclear condensates. Applied to killswitch-targeted nucleoli, mass spectrometry revealed selective depletion of ~20 RNA-binding proteins, demonstrating condensate-material-property–dependent partitioning.

04.06.2025 15:29 👍 0 🔁 0 💬 1 📌 0
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2/7
Using the nanobody system, killswitch can be targeted to a wide range of endogenous condensates, including nucleoli, nuclear speckles, chromocenters, and disease-specific condensates.

04.06.2025 15:29 👍 0 🔁 0 💬 1 📌 0
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1/7
Killswitch (KS) is a non-natural, self-associating micropeptide that can be genetically fused to condensate proteins or recruited via GFP-nanobody. It immobilizes scaffold proteins without affecting soluble pools—letting us perturb condensates selectively in live cells.

04.06.2025 15:29 👍 0 🔁 0 💬 1 📌 0

Special thanks to the great team that made this work possible: @idamarii.bsky.social Pablo Fernandez-Pernas, Melanie A, Matt C, Alex M, Melanie P-S @nvastenhouw.bsky.social ‪@weitzmanlab.bsky.social @floriangrebien.bsky.social @aktast.bsky.social @molgen.mpg.de @childrensphila.bsky.social

04.06.2025 15:29 👍 2 🔁 1 💬 1 📌 0

What controls condensate composition and function beyond binding stoichiometry? We show that condensate microenvironments play a key role, and can be probed by a micropeptide killswitch in live cells. www.nature.com/articles/s41... in @nature.com ‬ with @yaotianzhang.bsky.social Denes Hnisz & team.

04.06.2025 15:29 👍 16 🔁 7 💬 2 📌 4
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In summary, the killswitch is a versatile tool that alters condensate material properties in live cells. It revealed that condensate composition and functions rely on their microenvironments, paving the way for new biological insights and therapeutic strategies.

04.06.2025 15:23 👍 0 🔁 0 💬 0 📌 0

5/7
In adenoviral 52K condensates, killswitch reduced dynamics and blocked recruitment of capsid protein IIIa, despite preserved binding interfaces. Viral progeny production dropped >90%. The KS thus uncovers hidden roles of condensate microenvironments for condensate regulation.

04.06.2025 15:21 👍 0 🔁 0 💬 0 📌 0

4/7
Targeting BRD4::NUT condensates with killswitch disrupted RNA Pol II partitioning and reduced transcription. In NUP98::KDM5A-driven AML cells, killswitch caused proteasome-mediated degradation of fusion condensates and impaired leukemia cell growth.

04.06.2025 15:21 👍 0 🔁 0 💬 1 📌 0
Post image

3/7
To analyze compositional changes, we developed NuFANCI, a FACS-based method to isolate nuclear condensates. Applied to killswitch-targeted nucleoli, mass spectrometry revealed selective depletion of ~20 RNA-binding proteins, demonstrating condensate-material-property–dependent partitioning.

04.06.2025 15:21 👍 0 🔁 0 💬 1 📌 0
Post image

2/7
Using the nanobody system, killswitch can be targeted to a wide range of endogenous condensates, including nucleoli, nuclear speckles, chromocenters, and disease-specific condensates.

04.06.2025 15:21 👍 0 🔁 0 💬 1 📌 0
Post image

Killswitch (KS) is a non-natural, self-associating micropeptide that can be genetically fused to condensate proteins or recruited via GFP-nanobody. It immobilizes scaffold proteins without affecting soluble pools—letting us perturb condensates selectively in live cells.

04.06.2025 15:21 👍 0 🔁 0 💬 1 📌 0

Special thanks to the great team that made this work possible: @idamarii.bsky.social Pablo, Melanie, Matt, Alex, Melanie P-S. @nvastenhouw.bsky.social ‪‪ @floriangrebien.bsky.social @matthewkraushar.bsky.social @aktast.bsky.social @molgen.mpg.de

04.06.2025 15:21 👍 1 🔁 0 💬 1 📌 0

Congrats Julian!! 🤩🥳

02.04.2025 18:38 👍 1 🔁 0 💬 0 📌 0