PloS one, 2011-09, Vol.6 (9), p.e25378
2011
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- Autor(en) / Beteiligte
- Titel
- Hepatitis E virus ORF2 protein activates the pro-apoptotic gene CHOP and anti-apoptotic heat shock proteins
- Ist Teil von
- PloS one, 2011-09, Vol.6 (9), p.e25378
- Ort / Verlag
- United States: Public Library of Science
- Erscheinungsjahr
- 2011
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Hepatitis E virus (HEV) is a non-enveloped plus-strand RNA virus that causes acute hepatitis. The capsid protein open reading frame 2 (ORF2) is known to induce endoplasmic reticulum stress in ORF2 expressing cells. In this study we found that HEV ORF2 activates the expression of the pro-apoptotic gene C/EBP homologous protein (CHOP). ORF2 stimulates the CHOP promoter mainly through AARE (amino acid response elements) and to a minor extent the ERSE (endoplasmic reticulum stress response elements). Activating transcription factor 4 (ATF4) protein binds and activates the AARE regulatory sites of the CHOP promoter. ORF2 expression also leads to increased phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α) that in turn initiates the translation of ATF4 mRNA. The pro-apoptotic gene CHOP is an important trigger to initiate endoplasmic reticulum stress induced apoptosis. However, the activation of CHOP by ORF2 in this study did not induce apoptosis, nor did BCL2-associated X protein (Bax) translocate to mitochondria. Microarray analysis revealed an ORF2 specific increased expression of chaperones Hsp72, Hsp70B', and co-chaperone Hsp40. Co-immunoprecipitation (Co-IP) and in silico molecular docking analysis suggests that HEV ORF2 interacts with Hsp72. In addition, Hsp72 shows nuclear accumulation in ORF2 expressing cells. These data provide new insight into simultaneously occurring counter-acting effects of HEV ORF2 that may be part of a strategy to prevent host suicide before completion of the viral replication cycle.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1932-6203eISSN: 1932-6203DOI: 10.1371/journal.pone.0025378Titel-ID: cdi_plos_journals_1308506401
- Format
- –
- Schlagworte
- Activating transcription factor 4, Activating Transcription Factor 4 - genetics, Activating Transcription Factor 4 - metabolism, Amino acids, Analysis, Antigens, Apoptosis, BAX protein, Bcl-x protein, Biology, Biomedical research, Blotting, Western, Capsid protein, CCAAT/enhancer-binding protein, Cell Line, Chaperones, Cytomegalovirus, DNA microarrays, Endoplasmic reticulum, Eukaryotic Initiation Factor-2 - genetics, Eukaryotic Initiation Factor-2 - metabolism, Gene expression, Gene therapy, Genes, Genetic algorithms, Genomes, Heat shock proteins, Hepatitis, Hepatitis E virus - metabolism, Homology, HSP40 Heat-Shock Proteins - genetics, HSP40 Heat-Shock Proteins - metabolism, Hsp40 protein, HSP70 Heat-Shock Proteins - genetics, HSP70 Heat-Shock Proteins - metabolism, HSP72 Heat-Shock Proteins - genetics, HSP72 Heat-Shock Proteins - metabolism, Hsp72 protein, Humans, Immunoprecipitation, Initiation factor eIF-2α, Kinases, Medical schools, Mitochondria, Molecular docking, Oligonucleotide Array Sequence Analysis, Phosphorylation, Promoter Regions, Genetic - genetics, Promoter Regions, Genetic - physiology, Protein Binding, Proteins, Real-Time Polymerase Chain Reaction, Regulatory sequences, Ribonucleic acid, RNA, RNA viruses, Stress, Stresses, Suicide, Transcription Factor CHOP - genetics, Transcription Factor CHOP - metabolism, Transcription factors, Translation (Genetics), Viral proteins, Viral Proteins - genetics, Viral Proteins - metabolism, Viruses