3CD, but not 3C, cleaves the VP1/2A site efficiently during Aichi virus polyprotein processing through interaction with 2A

Jun Sasaki, Kumiko Ishikawa, Koki Taniguchi

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3 Citations (Scopus)


Picornavirus genomes are translated into a single large polyprotein, which is processed by virus-encoded proteases into individual functional proteins. 3C of all picornaviruses is a protease, and the leader (L) and 2A proteins of some picornaviruses are also involved in polyprotein processing. Aichi virus (AiV), which is associated with acute gastroenteritis in humans, is a member of the genus Kobuvirus of the family Picornaviridae. The AiV L and 2A proteins have already been shown to exhibit no protease activity. In this study, we investigated AiV polyprotein processing by 3C and 3CD using a cell-free translation system. 3C and 3CD were capable of processing the polyprotein in trans; 3C, however, cleaved the VP1/2A site inefficiently, while 3CD cleaved this site almost completely. Mammalian two-hybrid and coimmunoprecipitation assays showed an interaction between 2A and 3CD. Using a 3CD mutant and various 2A mutants of substrate proteins, we showed a clear correlation between the 2A-3CD interaction and the VP1/2A cleavage by 3CD. Thus, this study suggests that tight interaction of 3CD with the 2A region of a precursor protein is required for efficient cleavage at the VP1/2A site.

Original languageEnglish
Pages (from-to)592-598
Number of pages7
JournalVirus Research
Issue number2
Publication statusPublished - 01-02-2012


All Science Journal Classification (ASJC) codes

  • Cancer Research
  • Virology
  • Infectious Diseases

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