Study reveals NANOG protein forms self-limiting structures that regulate DNA dynamics in stem cells
Researchers report that NANOG, a transcription factor critical for embryonic stem cell pluripotency, assembles into self-limiting micelles at high concentrations and drives a sol-gel transition that modulates DNA dynamics. Unlike other intrinsically disordered proteins that form unbounded condensates, NANOG forms structured micelles with exposed DNA-binding domains, a finding established through molecular dynamics simulations, mass photometry, and Cryo-EM. The results suggest NANOG may regulate gene expression by generating local gel-like environments that restrict genome dynamics and could encode mechanical memory in gene regulatory networks.
A preprint study posted simultaneously to arXiv and bioRxiv investigates the rheological properties of NANOG, a transcription factor essential for maintaining pluripotency in embryonic stem cells. Using a combination of molecular dynamics simulations, mass photometry, and Cryo-EM imaging, the researchers found that at high concentrations NANOG forms macroscopic aging gels whose formation depends on its intrinsically disordered domain. Crucially, rather than forming the unbounded condensates typical of other intrinsically disordered proteins, NANOG assembles into self-limiting micelles that keep their DNA-binding domains exposed on the surface. These micelles were shown to stabilize DNA entanglements and thereby modulate DNA dynamics in ways that could influence gene regulation. The authors conjecture that NANOG contributes to gene expression control by creating localized gel-like microenvironments that restrict genome mobility. They further propose that the aging behavior of these gels could imprint a form of mechanical memory into gene regulatory networks, potentially influencing cell fate decisions over time.
What's missing
The study is a preprint and has not yet undergone peer review. Key open questions include whether the self-limiting micelle behavior and sol-gel transition observed in vitro occur at physiologically relevant NANOG concentrations inside living cells, and whether the conjectured mechanical memory in gene regulatory networks has any measurable functional consequence in vivo. The causal link between NANOG gel formation and actual gene expression changes remains to be experimentally demonstrated.
What different sources said
- arXiv physicsCenter
NANOG assembles into self-limiting aging micelles that drive a sol-gel transition and modulate DNA dynamics
- bioRxivCenter
NANOG assembles into self-limiting aging micelles that drive a sol-gel transition and modulate DNA dynamics
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.