Study reveals NANOG protein forms self-limiting structures that regulate DNA dynamics in stem cells
Researchers discovered that NANOG, a transcription factor crucial for embryonic stem cell pluripotency, assembles into self-limiting aging micelles at high concentrations rather than forming unbounded condensates like other disordered proteins. Using molecular dynamics simulations, mass photometry, and cryo-electron microscopy, the team found these micelles stabilize DNA entanglements and restrict genome dynamics. The findings suggest NANOG may regulate gene expression by creating localized gel-like environments and that its aging could imprint mechanical memory in gene regulatory networks.
A new study combining computational and experimental techniques reveals that the NANOG protein exhibits unusual assembly behavior compared to other intrinsically disordered proteins. At high concentrations, NANOG forms macroscopic aging gels dependent on its intrinsically disordered domain, but uniquely assembles into self-limiting micelles with exposed DNA-binding domains rather than forming unbounded condensates. Using molecular dynamics simulations, mass photometry, and cryo-electron microscopy, researchers demonstrated that these micelles can stabilize DNA entanglements and modulate DNA dynamics. The work suggests NANOG may contribute to gene regulation by establishing local gel-like environments that restrict genome dynamics, and proposes that the protein's aging process may create mechanical memory within gene regulatory networks. This discovery provides new insights into how transcription factors organize cellular environments to control gene expression in embryonic stem cells.
What's missing
The study's limitations regarding the in vivo relevance of high-concentration conditions used in experiments, the extent to which findings apply beyond embryonic stem cells, and the specific mechanisms by which mechanical memory in gene regulatory networks would functionally impact pluripotency maintenance are not detailed in the abstracts provided.
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.