A bacterial nucleolus for cold adaptation
- 1Biozentrum, University of Basel, Basel, Switzerland
Abstract
Compartmentalisation enables cells to spatially organise essential biochemical processes. This is exemplified by the eukaryotic nucleolus, which concentrates the machinery for ribosome biogenesis. Bacteria are generally thought to lack an equivalent compartment. Here we discover a nucleolus-like condensate in Escherichia coli that emerges at rDNA loci during cold adaptation to spatially organise and promote ribosome biogenesis. Low temperatures, which stabilise RNA secondary structures, induce accumulation of the RNA-remodelling enzyme CsdA. This raises the cellular CsdA concentration above its condensation threshold, driving condensate formation at rDNA loci when rRNA transcription is active. CsdA compartments enrich the rRNA transcription machinery and ribosome-biogenesis factors, spatially linking rRNA synthesis to downstream processing and assembly. Disrupting CsdA condensation impairs ribosome maturation and reduces bacterial adaptation to cold temperature, demonstrating functional importance of condensate formation. Comparative genomics suggests that analogous condensate-forming RNA remodelling enzymes have evolved repeatedly across diverse bacterial lineages. Our findings establish biomolecular condensates as a unifying organisational principle of ribosome biogenesis across the tree of life and suggest that adaptive compartmentalisation can emerge when environmental conditions challenge the efficiency of essential biochemical processes.
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BibTeX
@misc{gut2026bacterial,
title = {{A bacterial nucleolus for cold adaptation}},
author = {M. J. Gut and K. Dorner and S. Abegg and N. S. Qureshi and K. Ramachandran and A. Loynton-Ferrand and R. Prakapaite and A. Schmidt and T. A. Williams and O. Duss and M. Hondele},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.17.752289},
url = {https://www.biorxiv.org/content/10.64898/2026.09.17.752289v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - A bacterial nucleolus for cold adaptation
AU - M. J. Gut
AU - K. Dorner
AU - S. Abegg
AU - N. S. Qureshi
AU - K. Ramachandran
AU - A. Loynton-Ferrand
AU - R. Prakapaite
AU - A. Schmidt
AU - T. A. Williams
AU - O. Duss
AU - M. Hondele
PY - 2026
DA - 2026/09/17
PB - bioRxiv
DO - 10.64898/2026.09.17.752289
UR - https://www.biorxiv.org/content/10.64898/2026.09.17.752289v1
AB - Compartmentalisation enables cells to spatially organise essential biochemical processes. This is exemplified by the eukaryotic nucleolus, which concentrates the machinery for ribosome biogenesis. Bacteria are generally thought to lack an equivalent compartment. Here we discover a nucleolus-like condensate in Escherichia coli that emerges at rDNA loci during cold adaptation to spatially organise and promote ribosome biogenesis. Low temperatures, which stabilise RNA secondary structures, induce accumulation of the RNA-remodelling enzyme CsdA. This raises the cellular CsdA concentration above its condensation threshold, driving condensate formation at rDNA loci when rRNA transcription is active. CsdA compartments enrich the rRNA transcription machinery and ribosome-biogenesis factors, spatially linking rRNA synthesis to downstream processing and assembly. Disrupting CsdA condensation impairs ribosome maturation and reduces bacterial adaptation to cold temperature, demonstrating functional importance of condensate formation. Comparative genomics suggests that analogous condensate-forming RNA remodelling enzymes have evolved repeatedly across diverse bacterial lineages. Our findings establish biomolecular condensates as a unifying organisational principle of ribosome biogenesis across the tree of life and suggest that adaptive compartmentalisation can emerge when environmental conditions challenge the efficiency of essential biochemical processes.
ER -