https://scholars.lib.ntu.edu.tw/handle/123456789/188113
Title: | The Conserved Serine 177 in the Delta Antigen of Hepatitis Delta Virus Is One Putative Phosphorylation Site and Is Required for Efficient Viral Rna Replication | Authors: | CHEN, DING-SHINN 陳培哲 |
Keywords: | PROTEIN-KINASE-C;B SURFACE-ANTIGEN;MOLECULAR-CLONING;TRANSCRIPTION;GENOME;PHOSPHOPROTEIN | Issue Date: | 2001 | Journal Volume: | VIROLOGY | Journal Issue: | n.19 | Start page/Pages: | 9087-9095 | Source: | JOURNAL OF | Abstract: | Hepatitis delta virus (HDV) small delta antigen (S-HDAg) plays a critical role in virus replication. We previously demonstrated that the S-HDAg phospholylation occurs on both serine and threonine residues. However, their biological significance and the exact phosphorylation sites of S- HDAg are still unknown. In this study, phosphorylated S-HDAg was detected only in the intracellular compartment, not in viral particles. In addition , the number of phospholylated isoforms of S-HDAg significantly increased with the extent of viral replication in transfection system. Site-directed mutagenesis showed that alanine replacement of serine 177, which is conserved among all the known HDV strains, resulted in reduced phosphorylation of S-HDAg, while the mutation of the other two conserved serine residues (2 and 123) had little effect. The S177A mutant dramatically decreased its capability in assisting HDV RNA replication, with a preferential and profound impairment of the antigenomic RNA replication. Furthermore, the viral RNA editing, a step relying upon antigenomic RNA replication, was also abolished by this mutation. These results suggested that phosphorylation of S-HDAg, with serine 177 as a presumable site, plays a critical role in viral RNA replication, especially in augmenting the replication of antigenomic RNA. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/95160 |
Appears in Collections: | 醫學系 |
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