Hepatitis Delta Virus Replication Generates Complexes of Large Hepatitis Delta Antigen and Antigenomic RNA That Affiliate with and Alter Nuclear Domain 10

AUTOR(ES)

Bell, Peter

FONTE

American Society for Microbiology

RESUMO

Hepatitis delta virus (HDV), a single-stranded RNA virus, bears a single coding region whose product, the hepatitis delta antigen (HDAg), is expressed in two isoforms, small (S-HDAg) and large (L-HDAg). S-HDAg is required for replication of HDV, while L-HDAg inhibits viral replication and is required for the envelopment of the HDV genomic RNA by hepatitis B virus proteins. Here we have examined the spatial distribution of HDV RNA and proteins in infected nuclei, with particular reference to specific nuclear domains. We found that L-HDAg was aggregated in specific nuclear domains and that over half of these domains were localized beside nuclear domain 10 (ND10). At later times, ND10-associated proteins like PML were found in larger HDAg complexes that had developed into apparently hollow spheres. In these larger complexes, PML was found chiefly in the rims of the spheres, while the known ND10 components Sp100, Daxx, and NDP55 were found in the centers of the spheres. Thus, ND10 proteins that normally are closely linked separate within HDAg-associated complexes. Viral RNA of antigenomic polarity, whether expressed from genomic RNA or directly from introduced plasmids, colocalizes with L-HDAg and the transcriptional repressor PML. In contrast, HDV genomic RNA was distributed more uniformly throughout the nucleus. These results suggest that different host protein complexes may assemble on viral RNA strands of different polarities, and they also suggest that this RNA virus, like DNA viruses, can alter the distribution of ND10-associated proteins. The fact that viral components specifically linked to repression of replication can associate with one of the ND10-associated proteins (PML) raises the possibility that this host protein may play a role in the regulation of HDV RNA synthesis.

Documentos Relacionados

• The Large Delta Antigen of Hepatitis Delta Virus Potently Inhibits Genomic but Not Antigenomic RNA Synthesis: a Mechanism Enabling Initiation of Viral Replication
• Large Hepatitis Delta Antigen Is Not a Suppressor of Hepatitis Delta Virus RNA Synthesis once RNA Replication Is Established
• Mutagenesis analysis of the self-cleavage domain of hepatitis delta virus antigenomic RNA.
• Hepatitis Delta Antigen Mediates the Nuclear Import of Hepatitis Delta Virus RNA
• Hepatitis Delta Virus RNA Encoding the Large Delta Antigen Cannot Sustain Replication due to Rapid Accumulation of Mutations Associated with RNA Editing