Functional Characterization of Nuclear Localization Signals in Kolmioviridae and Their Role in Nuclear Transport

Abstract

Kolmioviridae is a virus family that was expanded following the recent discovery of new agents in mammals and snakes. These new discoveries highlight a lack of knowledge about the evolutionary history of kolmioviruses. Acquiring insight about kolmiovirus replication and pathogenesis can contribute to an understanding of their phylogeny and provide new avenues for controlling emerging viral diseases and developing antiviral therapies and new diagnostic tools. Nuclear import, which is performed by the nuclear localization signal (NLS) present in the kolmiovirus protein’s genome, is a critical step in viral replication. The aim of this research was to identify and characterize the NLSs present in the complete genome of eight kolmioviruses and to study these NLSs using molecular tools to determine their role in the nuclear transport of fluorescently tagged viral proteins. Microscopic analysis of the subcellular localization of these proteins showed that most tested NLSs, and at least one NLS for each virus, were effective in mediating nuclear import, while others showed reduced or no activity. This suggests the presence of virus-specific strategies and possible evolutionary adaptations to different hosts and confirms the importance of nuclear transport in the Kolmioviridae family’s replication. These findings provide a foundation for further investigation into the molecular mechanisms governing kolmiovirus biology and host specificity.