ARF1 and infection: Furthermore, since the 27AAGKTT32 motif and T31 residue are essential for gcARF1 binding to GDP, the inhibition on the GCRV replication caused by the deletion of 27AAGKTT32 motif of gcARF1 and the mutation of ARF1(T31N) suggest that the GTPase activity of gcARF1 is important for GCRV replication and infection.