VIRP1 protein shapes nuclear condensates and facilitates potato spindle tuber viroid infection
Researchers identified how VIRP1, a host protein in potato plants, forms nuclear condensates and promotes infection by potato spindle tuber viroid (PSTVd). VIRP1 is the only Solanaceae BET protein with a proline-rich domain that binds PSTVd RNA, and its bromodomain and nuclear localization are critical for efficient viroid accumulation. The findings reveal a mechanism linking chromatin regulation, phase separation, and early viroid infection establishment.
A new study on bioRxiv demonstrates that VIRP1, a bromodomain-containing protein in potato plants, plays a central role in facilitating potato spindle tuber viroid (PSTVd) infection through nuclear condensate formation. The researchers found that VIRP1 is uniquely positioned among Solanaceae BET proteins due to its proline-rich domain overlapping the PSTVd-binding site. VIRP1-deficient plants showed delayed flowering and increased sensitivity to the stress hormone ABA, with altered expression of stress-related genes. Functional studies revealed that VIRP1 forms phase-separated condensates both in living cells and in vitro, with condensate morphology altered by PSTVd RNA and mutations in conserved bromodomain residues. The bromodomain and nuclear localization of VIRP1 proved essential for efficient viroid accumulation, particularly during early infection stages, though the intrinsically disordered C-terminal domain was dispensable. These results suggest VIRP1 acts as a host nuclear factor integrating chromatin functions with early viroid infection mechanisms.
What's missing
The study does not discuss potential agricultural or practical applications for controlling PSTVd infection through VIRP1 manipulation, nor does it address whether findings in Solanaceae plants might generalize to viroid infections in other plant families.
What different sources said
- bioRxivCenter
VIRP1 bromodomain shapes nuclear condensate formation and has a positive effect on PSTVd accumulation
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.