In Vivo Interaction of the Hepatitis Delta Virus Small Antigen with the ELAV-Like Protein HuR
Ana Casaca1, Margarida Fardilha2, Edgar da Cruz e Silva2, Celso Cunha*, 1
Identifiers and Pagination:Year: 2011
First Page: 12
Last Page: 21
Publisher Id: TOVJ-5-12
Article History:Received Date: 30/7/2010
Revision Received Date: 27/10/2010
Acceptance Date: 4/11/2010
Electronic publication date: 24/3/2011
Collection year: 2011
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The small and large delta antigens (S-HDAg and L-HDAg, respectively) represent two forms of the only protein encoded by the hepatitis delta virus (HDV) RNA genome. Consequently, HDV relies, at a large extent, on the host cell machinery for replication and transcription. Until now, only a limited number of cellular proteins were identified as S-HDAg or L-HDAg partners being involved in the modulation of the virus life cycle. In an attempt to identify cellular S-HDAg-binding proteins we made use of a yeast two-hybrid approach to screen a human liver cDNA library. We were able to identify HuR, a ubiquitously expressed protein involved in RNA stabilization, as an S-HDAg partner both in vitro and in vivo. HuR was found to be overexpressed and colocalize with HDAg in human hepatoma cells. siRNA knockdown of HuR mRNA resulted in inhibition of S-HDAg and L-HDAg expression.