|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
|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.
|Appears in Collections:||醫學系|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.