# Importin Alpha Is Implicated in the Nuclear Import of Novel Duck Reovirus Protein p18

## TL;DR

This study finds that a duck virus protein, p18, enters the cell nucleus with the help of importin alpha proteins, and its nuclear entry does not require active viral infection.

## Contribution

The study identifies importin alpha as a key transporter for p18 nuclear import and shows that this process is independent of viral replication.

## Key findings

- p18 localizes to the nucleus in transfected cells.
- Importin α1, α3, α4, α5, and α7 interact with p18.
- The C-terminal region of p18 is essential for its nuclear localization.

## Abstract

Novel duck reovirus encodes a new nucleus-localized protein, p18. We aimed to investigate whether the nuclear entry of p18 is dependent on viral replication, identify the cellular proteins that interact with p18, and determine the transporters involved in the nuclear import. The subcellular localization of p18 was observed by confocal microscopy. Cellular proteins interacting with p18 were identified through data-independent acquisition qualitative proteomics. The interaction between p18 and importin α was determined by confocal microscopy, co-immunoprecipitation (Co-IP) and molecular docking. We observed that p18 was localized to the nucleus in transfected cells. Importin α1, α3, α4, α5, and α7 were colocalized and co-immunoprecipitated with p18. The importin α/β1 pathway inhibitor reduced the nuclear distribution of p18. The truncated form of p18, lacking the C-terminal region, was predominantly distributed in the cytoplasm. Collectively, our research suggests that the nuclear entry of p18 is independent of viral infection, importin α is implicated in the nuclear import of p18, and the C-terminal region of p18 is crucial for nuclear localization.