A 2026 review in Molecular Biology Reports identifies polypyrimidine tract-binding protein 1 (PTBP1) as a host RNA-binding protein involved in viral gene expression, genome replication and modulation of antiviral responses. The article synthesizes existing mechanistic evidence rather than reporting a new experiment. Across the reviewed studies, PTBP1 can act either in support of viral infection or against it, depending on the virus, cellular pathway and stage of infection.
PTBP1 is a ubiquitous protein with four RNA recognition motifs (RRMs) that performs regulatory functions involving alternative splicing, RNA stability, RNA localization and translation. It shuttles between the nucleus and cytoplasm, allowing it to act on RNA in either compartment. The review focuses particularly on its role in the internal ribosome entry site (IRES)-dependent translation used by enteroviruses and hepatitis C virus.
It also examines PTBP1-dependent RNA stabilization, long-distance RNA interactions and genome cyclization in flaviviruses such as dengue virus and Japanese encephalitis virus, as well as recent evidence concerning coronavirus RNA metabolism. PTBP1 can therefore contribute to more than one stage of viral infection. Regulation of IRES-dependent translation links the protein to viral protein production, while stabilization of viral RNA and interactions among distant RNA regions can help organize the genome and support replication.
The review also describes evidence that PTBP1 participates in innate-immunity signaling and stress-granule biology, giving it a potential proviral or antiviral role depending on the biological context. These opposing effects mean that PTBP1 cannot be assigned a single function across viruses or infection stages. The authors consider whether PTBP1 could serve as a host-directed antiviral target, but identify substantial hurdles.
The protein is multifunctional and participates in essential cellular RNA regulation, so broad inhibition could affect host processes as well as viral infection. Because the article is a review, its conclusions summarize and compare evidence from earlier research; the supplied abstract does not provide new datasets, clinical findings or direct human treatment results.
Subject of Research: Review of PTBP1 functions in viral RNA translation, replication and immune modulation
Article Title: PTBP1 at the host–virus interface: mechanistic roles in viral RNA translation, replication, and immune modulation
Article References: Kajal, Pandey, A., Yadav, R., Shukla, R., & Mishra, S. (2026). PTBP1 at the host–virus interface: mechanistic roles in viral RNA translation, replication, and immune modulation. Molecular Biology Reports, 53(1), Article 1526. https://doi.org/10.1007/s11033-026-12713-x
Image Credits: AI Generated
DOI: 10.1007/s11033-026-12713-x
Keywords: PTBP1, viral RNA, RNA translation, IRES, genome replication, host-virus interaction, innate immunity, flaviviruses, coronaviruses, host-directed antivirals, host, virus
