January 5th, 2025
Recent Publications Harnessing the Power of Translatomics
Every week we provide a digest of a small number of recent interesting papers in the field of translatomics.
In this week’s Sunday papers, Wang et al. identified the importance of analysing both transcriptional and translational landscapes to fully understand plant’s defence mechanism. Brown and May identified how the p26 movement protein of Pea enation mosaic virus 2 affects the host cellular processes. Wong et al. showed that Zika virus infection caused selective enrichment of endoplasmic reticulum-associated proteins to facilitate viral replication.
RNA-seq and Ribosome Profiling Reveal the Translational Landscape of Rice in Response to Rice Stripe Virus Infection
Viruses, 2024
Wang, C., Tang, Y., Zhou, C., Li, S., Chen, J. and Sun, Z.
Rice Stripe Virus (RSV) significantly threatens rice yields. This study employed RNA sequencing (RNA-seq) and ribosome profiling to examine the transcriptional and translational responses of rice seedlings to RSV infection. The findings indicated that translational reprogramming is a crucial component of the plant’s defence mechanism, functioning independently of transcriptional changes. In this study, less than half of the differentially expressed genes exhibited concordance between transcription and translation levels. RSV infection also led to substantial alterations in translational efficiency for numerous genes, suggesting that the virus selectively manipulates translation to enhance its pathogenicity.
The study determined that genes with altered translational efficiency could guide genetic engineering or selective breeding to enhance rice resistance to RSV and similar viruses. These results underscored the importance of analysing both transcriptional and translational landscapes to fully understand plant responses to viral infections.
Viral condensates formed by Pea enation mosaic virus 2 sequester ribosomal components and suppress translation
Virology, 2024
Brown, S.L. and May, J.P.
In this study, the authors determined how the p26 movement protein of Pea enation mosaic virus 2 (PEMV2) influences host cellular processes. The researchers found that p26, an intrinsically disordered protein, forms viral condensates through phase separation. Mass spectrometry analysis of these condensates revealed an enrichment of RNA-binding proteins involved in translation and ribosome biogenesis. Functional assays, including puromycin incorporation and polysome profiling, demonstrated that p26 expression suppresses ribosome assembly and overall protein translation in Nicotiana benthamiana plants. This suppression mirrored defects observed during late stages of PEMV2 infection.
Although p26 interacts with the 2′-O-methyltransferase fibrillarin, it does not inhibit translation by altering ribosomal RNA (rRNA) methylation. Instead, p26 binds directly to rRNAs, decreasing their solubility and disrupting ribosome assembly. The study suggested that this disruption of ribosome assembly and translation by p26 during late PEMV2 infection may facilitate stages of the virus replication cycle that are incompatible with active host translation, such as systemic movement.
Flaviviruses induce ER-specific remodelling of protein synthesis
PLoS pathogens, 2024
Wong, H.H., Crudgington, D.R.K., Siu, L. and Sanyal, S.
The authors explored how flaviviruses, such as Zika virus (ZIKV), manipulate the host cell’s endoplasmic reticulum (ER) to facilitate their replication. Commonly, cellular membrane proteins are targeted to the ER via the signal recognition particle (SRP)-dependent pathway, involving SRP54 and its receptor components SRα and SRβ. However, this research revealed that ZIKV can bypass the conventional SRP pathway by directly interacting with SRP54, independent of SRα and SRβ. This interaction enables the viral polyprotein to be efficiently targeted to the ER, ensuring successful replication.
Through polysome profiling analysis, ZIKV infection led to an increased association of polysomes with proteins involved in ER membrane expansion, lipid metabolism, and secretory processes. This indicated the reprogramming of the ER’s translational landscape, selectively enhancing the synthesis of host proteins involved in ER membrane expansion, lipid metabolism, and secretory processes, while reducing the production of RNA-binding proteins and stress granule components.
This strategic remodelling supports viral replication and suppresses antiviral responses, highlighting a sophisticated mechanism by which flaviviruses exploit host cellular machinery.