Protein 1A functions as a suppressor of RNA-mediated gene silencing, an antiviral defense mechanism of insect cells. Binds to long dsRNA and to a lesser extent, to siRNA. RNA-directed RNA polymerase replicates genomic and antigenomic RNA. a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) Protein 1A might be expressed through a ribosomal skip from one codon to the next without formation of a peptide bond.