Full length and protease domain activity of chikungunya virus nsP2 differ from other alphavirus nsP2 proteases in recognition of small peptide substrates

The protease role of alphavirus nsP2 is critical for virus replication as only the virus protease processes the viral non-structural polypeptide. We show chikungunya nsP2 protease possesses different substrate specificity to the canonical alphavirus nsP2 polyprotein cleavage specificity.

Intracellular Interference of Infectious Bursal Disease Virus

ABSTRACT A search for dominant-negative mutant polypeptides hampering infectious bursal disease virus (IBDV) replication has been undertaken. We have found that expression of a mutant version of the VP3 structural polypeptide known as VP3/M3, partially lacking the domain responsible for the interaction with the virus-encoded RNA polymerase, efficiently interferes with the IBDV replication cycle. Transformed cells stably expressing VP3/M3 show a significant reduction (up to 96%) in their ability to support IBDV growth. Our findings provide a new tool for the characterization of the IBDV replication cycle and might facilitate the generation of genetically modified chicken lines with a reduced susceptibility to IBDV infection.