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Sachin Kotak

@spindlebehavior.bsky.social

89 followers 117 following 17 posts

Cell Biologist interested in fundamental cell division processes working @iiscbangalore

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Sachin Kotak @spindlebehavior.bsky.social · 15/09/2026

Can light build centrosome-like activity? 💡🔬 Yes! We introduce LISA (Light-Induced Spindle Assembly), now in @emboreports.org. By clustering Aurora A with optogenetics, we build centrosome-like activity that nucleates microtubules and rescues spindle defects after centrosome loss. shorturl.at/9h3VQ

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Sachin Kotak @spindlebehavior.bsky.social · 13/09/2025

Finally, by tracking nucleolar organization and chromatin–chromatin contacts (via 4C analysis), we show that perturbing nuclear organization directly disrupts chromatin organization at mitotic exit. This work highlights the biological significance of spindle pole disassembly at mitotic exit.

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Sachin Kotak @spindlebehavior.bsky.social · 13/09/2025

NuMA accumulation at spindle poles depends on: • dynein/dynactin (trucks) • its coiled-coil domain (cranes), and • its ability to form multivalent cation-π interactions through its intrinsically disordered region (IDR) at the C-terminus (hooks in cyan).

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Sachin Kotak @spindlebehavior.bsky.social · 13/09/2025

When Aurora A is inactivated, we found that NuMA, a conserved spindle pole protein, undergoes a material state transition from dynamic to solid, and abnormally accumulates at the spindle poles. This abnormal “accumulation” causes NuMA segregated chromosomes/nuclei to bend around them.

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Sachin Kotak @spindlebehavior.bsky.social · 13/09/2025

- We found that Aurora A activity in anaphase is crucial for shaping the nucleus during mitotic exit. To probe this, we built a cyclin-B1-based degron tool that enables rapid, phase-specific degradation of Aurora A, right as cells exit mitosis.

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Sachin Kotak @spindlebehavior.bsky.social · 13/09/2025

Happy to share our work in @embojournal 👉 shorturl.at/zXNyn For decades, we’ve known cells dismantle & rebuild the nuclear envelope in sync with spindle poles. But why does this coordination matter? And how do pole material properties ensure error-free division? Follow this thread to know more 👇

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