Bold opening: Nuclear shortcuts in our cells may quietly power viral spread. And this is the part most people miss: tiny nuclear structures could be pivotal players in how viruses modify and move their genetic messages. Here’s a clearer look at what researchers have found and why it matters.
Recent studies show that nuclear speckles—dynamic, membraneless hubs inside the nucleus—play a crucial part in editing viral messenger RNAs (mRNAs) and in ferrying them out of the nucleus. Because of this, nuclear speckles are a key topic for understanding how viral infections unfold.
When cells are infected by herpes simplex virus type 1 (HSV-1), the nucleus undergoes dramatic remodeling. The virus creates dedicated replication compartments and causes chromatin to shift toward the nuclear edge. In parallel, teams from the University of Jyväskylä and Bar-Ilan University found that HSV-1 infection also reshapes nuclear speckles, which are essential for processing messenger RNAs.
What exactly do nuclear speckles do? They act as dynamic gathering places where factors involved in gene expression are stored, assembled, and modified. Both the host’s and the virus’s messenger RNAs pass through these speckles for processing. When speckles disassemble, the export of viral mRNAs from the nucleus is severely hampered, according to Maija Vihinen-Ranta, Research Director at the University of Jyväskylä.
In summary, nuclear speckles appear to function as regulatory hubs that fine‑tune viral mRNA processing and control their journey from the nucleus to the rest of the cell. Without functional speckles, viral replication stalls, and infection cannot progress normally.
Understanding how viruses hijack host cells and leverage cellular machinery could open new avenues for treating and preventing viral diseases, notes Vihinen-Ranta.
This work was published in Proceedings of the National Academy of Sciences (PNAS) and was a collaborative effort with Professor Shav-Tal’s group at Bar-Ilan University (Israel). The study received support from the U.S. National Institutes of Health, the Jane and Aatos Erkko Foundation, the Academy of Finland, the Erasmus program of the European Union, and the EU’s Horizon 2020 framework.
Source:
Nadav-Eliyahu, S., et al. (2026). Nuclear speckles are regulatory hubs for viral and host mRNA expression during HSV-1 infection. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2511555123.
