The DNA Architectural Protein HMGB1 Facilitates RTA-Mediated Viral Gene Expression in Gamma-2 Herpesviruses
AUTOR(ES)
Jung Song, Moon
FONTE
American Society for Microbiology
RESUMO
Replication and transcription activator (RTA), an immediate-early gene product of gamma-2 herpesviruses including Kaposi's sarcoma-associated herpesvirus (KSHV) and murine gamma herpesvirus 68 (MHV-68), plays a critical role in controlling the viral life cycle. RTA acts as a strong transcription activator for several downstream genes of KSHV and MHV-68 through direct DNA binding, as well as via indirect mechanisms. HMGB1 (also called HMG-1) protein is a highly conserved nonhistone chromatin protein with the ability to bind and bend DNA. HMGB1 protein promoted RTA binding to different RTA target sites in vitro, with greater enhancement to low-affinity sites than to high-affinity sites. Box A or box B and homologues of HMGB1 also enhanced RTA binding to DNA. Transient transfection of HMGB1 stimulated RTA transactivation of RTA-responsive promoters from KSHV and MHV-68. Furthermore, MHV-68 viral gene expression, as well as viral replication, was significantly reduced in HMGB1-deficient cells than in the wild type. This abated viral gene expression was partially restored by HMGB1 transfection into HMGB1−/− cells. These results suggest an important function of the DNA architectural protein, HMGB1, in RTA-mediated gene expression, as well as viral replication in gamma-2 herpesviruses.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=524970Documentos Relacionados
- The DNA chaperone HMGB1 facilitates ACF/CHRAC-dependent nucleosome sliding
- The DNA Architectural Protein HMGB1 Displays Two Distinct Modes of Action That Promote Enhanceosome Assembly
- Principal Role of TRAP/Mediator and SWI/SNF Complexes in Kaposi's Sarcoma-Associated Herpesvirus RTA-Mediated Lytic Reactivation
- NEW EMBO MEMBER’S REVIEW: The double life of HMGB1 chromatin protein: architectural factor and extracellular signal
- Two Distinct Gamma-2 Herpesviruses in African Green Monkeys: a Second Gamma-2 Herpesvirus Lineage among Old World Primates?