Identification of FAM111A as an SV40 Host Range Restriction and Adenovirus Helper Factor
Open Access
- 18 October 2012
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLoS Pathogens
- Vol. 8 (10), e1002949
- https://doi.org/10.1371/journal.ppat.1002949
Abstract
The small genome of polyomaviruses encodes a limited number of proteins that are highly dependent on interactions with host cell proteins for efficient viral replication. The SV40 large T antigen (LT) contains several discrete functional domains including the LXCXE or RB-binding motif, the DNA binding and helicase domains that contribute to the viral life cycle. In addition, the LT C-terminal region contains the host range and adenovirus helper functions required for lytic infection in certain restrictive cell types. To understand how LT affects the host cell to facilitate viral replication, we expressed full-length or functional domains of LT in cells, identified interacting host proteins and carried out expression profiling. LT perturbed the expression of p53 target genes and subsets of cell-cycle dependent genes regulated by the DREAM and the B-Myb-MuvB complexes. Affinity purification of LT followed by mass spectrometry revealed a specific interaction between the LT C-terminal region and FAM111A, a previously uncharacterized protein. Depletion of FAM111A recapitulated the effects of heterologous expression of the LT C-terminal region, including increased viral gene expression and lytic infection of SV40 host range mutants and adenovirus replication in restrictive cells. FAM111A functions as a host range restriction factor that is specifically targeted by SV40 LT. Viruses have evolved numerous mechanisms to counteract host cell defenses to facilitate productive infection. Simian Virus 40 (SV40) replication depends on specific interactions between large T antigen (LT) and a wide variety of host cell proteins. Although the LT C-terminal region has no evident enzymatic activity, mutations or deletions of this region significantly reduce the ability of the virus to replicate in restrictive cell types. Here, we identified host proteins that bind to LT and determined that the LT C-terminal region binds specifically to FAM111A. This physical interaction was required for efficient viral replication and sustained viral gene expression in restrictive cell types. In addition, RNAi-mediated knockdown of FAM111A levels in restrictive cells restored lytic infection of SV40 host range mutants and human adenovirus. These results indicate that FAM111A plays an important role in viral host range restriction. Our study provides insights into the viral-host perturbations caused by SV40 LT and the interaction of viruses with host restriction factors.Keywords
This publication has 36 references indexed in Scilit:
- Interpreting cancer genomes using systematic host network perturbations by tumour virus proteinsNature, 2012
- The MuvB complex sequentially recruits B-Myb and FoxM1 to promote mitotic gene expressionGenes & Development, 2012
- Defining the Human Deubiquitinating Enzyme Interaction LandscapeCell, 2009
- The tumor suppressor Cdc73 functionally associates with CPSF and CstF 3′ mRNA processing factorsProceedings of the National Academy of Sciences of the United States of America, 2009
- VirusMINT: a viral protein interaction databaseNucleic Acids Research, 2009
- A Protein Domain-Based Interactome Network for C. elegans Early EmbryogenesisCell, 2008
- Analyzing chromatin remodeling complexes using shotgun proteomics and normalized spectral abundance factorsMethods, 2006
- Crystal structure of SV40 large T-antigen bound to p53: interplay between a viral oncoprotein and a cellular tumor suppressorGenes & Development, 2006
- Gene set enrichment analysis: A knowledge-based approach for interpreting genome-wide expression profilesProceedings of the National Academy of Sciences of the United States of America, 2005
- Towards a proteome-scale map of the human protein–protein interaction networkNature, 2005