Polyadenylation of the mRNA of hepatitis delta virus is dependent on the structure of the nascent RNA and regulated by the small or large delta antigen

Abstract

During the hepatitis delta virus (HDV) RNA replication, synthesis of either the mRNA for the delta antigen (HDAg) or the full-length antigenomic RNA is determined by selective usage of the potent poly(A) signal on the antigenome. To elucidate the regulatory mechanism, HDV cDNA cotransfection system was used to examine the potential effect of the secondary structure of the nascent RNA and that of the HDAg on HDV polyadenylatlon in transfected cells. We found that when the nascent RNA species could fold itself to form the rodlike structure, the HDV polyadenylation was suppressed 3 to 5 fold by the HDAg. In addition, we observed that the small and the large HDAg exerted a similar suppresslve effect on the HDV polyadenylatlon, though they played different roles In HDV replication. We concluded that the HDV polyadenylation could be regulated by the structure of the nascent antigenomic RNA and by either the small or large HDAg. © 1994 Oxford University Press.