1. Academic Validation
  2. The cellular RNA helicase DDX1 interacts with coronavirus nonstructural protein 14 and enhances viral replication

The cellular RNA helicase DDX1 interacts with coronavirus nonstructural protein 14 and enhances viral replication

  • J Virol. 2010 Sep;84(17):8571-83. doi: 10.1128/JVI.00392-10.
Linghui Xu 1 Siti Khadijah Shouguo Fang Li Wang Felicia P L Tay Ding Xiang Liu
Affiliations

Affiliation

  • 1 Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore.
Abstract

The involvement of host proteins in the replication and transcription of viral RNA is a poorly understood area for many RNA viruses. For coronaviruses, it was long speculated that replication of the giant RNA genome and transcription of multiple subgenomic mRNA species by a unique discontinuous transcription mechanism may require host cofactors. To search for such cellular proteins, yeast two-hybrid screening was carried out by using the nonstructural protein 14 (nsp14) from the coronavirus infectious bronchitis virus (IBV) as a bait protein, leading to the identification of DDX1, a cellular RNA helicase in the DExD/H helicase family, as a potential interacting partner. This interaction was subsequently confirmed by coimmunoprecipitation assays with cells coexpressing the two proteins and with IBV-infected cells. Furthermore, the endogenous DDX1 protein was found to be relocated from the nucleus to the cytoplasm in IBV-infected cells. In addition to its interaction with IBV nsp14, DDX1 could also interact with the nsp14 protein from severe acute respiratory syndrome coronavirus (SARS-CoV), suggesting that interaction with DDX1 may be a general feature of coronavirus nsp14. The interacting domains were mapped to the C-terminal region of DDX1 containing motifs V and VI and to the N-terminal portion of nsp14. Manipulation of DDX1 expression, either by small interfering RNA-induced knockdown or by overexpression of a mutant DDX1 protein, confirmed that this interaction may enhance IBV replication. This study reveals that DDX1 contributes to efficient coronavirus replication in Cell Culture.

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