scholarly journals Epstein-Barr Virus Immediate-Early Protein Zta Co-Opts Mitochondrial Single-Stranded DNA Binding Protein To Promote Viral and Inhibit Mitochondrial DNA Replication

2008 ◽  
Vol 82 (9) ◽  
pp. 4647-4655 ◽  
Author(s):  
Andreas Wiedmer ◽  
Pu Wang ◽  
Jing Zhou ◽  
Andrew J. Rennekamp ◽  
Valeria Tiranti ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Lytic Replication ◽  
Single Stranded Dna ◽  
Barr Virus ◽  
Early Protein ◽  
Associated Proteins ◽  
Epstein Barr

ABSTRACT Disruption of cellular metabolic processes and usurpation of host proteins are hallmarks of herpesvirus lytic infection. Epstein-Barr virus (EBV) lytic replication is initiated by the immediate-early protein Zta. Zta is a multifunctional DNA binding protein that stimulates viral gene transcription, nucleates a replication complex at the viral origin of lytic replication, and inhibits cell cycle proliferation. To better understand these functions and identify cellular collaborators of Zta, we purified an epitope-tagged version of Zta in cells capable of supporting lytic replication. FLAG-tagged Zta was purified from a nuclear fraction using FLAG antibody immunopurification and peptide elution. Zta-associated proteins were isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by mass spectrometry. The Zta-associated proteins included members of the HSP70 family and various single-stranded DNA and RNA binding proteins. The nuclear replication protein A subunits (RPA70 and RPA32) and the human mitochondrial single-stranded DNA binding protein (mtSSB) were confirmed by Western blotting to be specifically enriched in the FLAG-Zta immunopurified complex. mtSSB coimmunoprecipitated with endogenous Zta during reactivation of EBV-positive Burkitt lymphoma and lymphoblastoid cell lines. Small interfering RNA depletion of mtSSB reduced Zta-induced lytic replication of EBV but had only a modest effect on transcription activation function. A point mutation in the Zta DNA binding domain (C189S), which is known to reduce lytic cycle replication, eliminated mtSSB association with Zta. The predominantly mitochondrial localization of mtSSB was shifted to partly nuclear localization in cells expressing Zta. Mitochondrial DNA synthesis and genome copy number were reduced by Zta-induced EBV lytic replication. We conclude that Zta interaction with mtSSB serves the dual function of facilitating viral and blocking mitochondrial DNA replication.

Structural features of the single-stranded DNA-binding protein of Epstein–Barr virus

2008 ◽  
Vol 161 (2) ◽  
pp. 172-187 ◽  
Author(s):  
E. Mumtsidu ◽  
A.M. Makhov ◽  
P.V. Konarev ◽  
D.I. Svergun ◽  
J.D. Griffith ◽  
...  
Keyword(s):  
Dna Binding ◽  
Epstein Barr Virus ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Structural Features ◽  
Single Stranded Dna ◽  
Barr Virus ◽  
Epstein Barr

A RAD52-like single-stranded DNA binding protein affects mitochondrial DNA repair by recombination

2012 ◽  
Vol 72 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Sabina Janicka ◽  
Kristina Kühn ◽  
Monique Le Ret ◽  
Geraldine Bonnard ◽  
Patrice Imbault ◽  
...  
Keyword(s):  
Dna Repair ◽  
Mitochondrial Dna ◽  
Dna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Single Stranded Dna ◽  
Mitochondrial Dna Repair

scholarly journals Epstein–Barr virus nuclear antigen 1 is a DNA-binding protein with strong RNA-binding activity

2004 ◽  
Vol 85 (10) ◽  
pp. 2755-2765 ◽  
Author(s):  
Chih-Chung Lu ◽  
Chia-Wei Wu ◽  
Shin C. Chang ◽  
Tzu-Yi Chen ◽  
Chwan-Ren Hu ◽  
...  
Keyword(s):  
Dna Binding ◽  
Epstein Barr Virus ◽  
Rna Binding ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Binding Activity ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Infected Cells ◽  
Epstein Barr

Epstein–Barr virus (EBV) nuclear antigen 1 (EBNA-1) plays key roles in both the regulation of gene expression and the replication of the EBV genome in latently infected cells. To characterize the RNA-binding activity of EBNA-1, it was demonstrated that EBNA-1 binds efficiently to RNA homopolymers that are composed of poly(G) and weakly to those composed of poly(U). All three RGG boxes of EBNA-1 contributed additively to poly(G)-binding activity and could mediate RNA binding when attached to a heterologous protein in an RNA gel mobility-shift assay. In vitro-transcribed EBV and non-EBV RNA probes revealed that EBNA-1 bound to most RNAs examined and the affinity increased as the content of G and U increased, as demonstrated in competition assays. Among these probes, the 5′ non-coding region (NCR) (nt 131–278) of hepatitis C virus RNA appeared to be the strongest competitor for EBNA-1 binding to the EBV-encoded small nuclear RNA 1 (EBER1) probe, whereas a mutant 5′ NCR RNA with partially disrupted secondary structure was a weak competitor. Furthermore, the interaction of endogenous EBNA-1 and EBER1 in EBV-infected cells was demonstrated by a ribonucleoprotein immunoprecipitation assay. These results revealed that EBNA-1 is a DNA-binding protein with strong binding activity to a relatively broad spectrum of RNA and suggested an additional biological impact of EBNA-1 through its ability to bind to RNA.

scholarly journals Characterization of Epstein-Barr Virus DNase and Its Interaction with the Major DNA Binding Protein

Virology ◽  
1995 ◽  
Vol 208 (2) ◽  
pp. 712-722 ◽  
Author(s):  
Su-Fang Lin ◽  
Tsuey-Ying Hsu ◽  
Mei-Ying Liu ◽  
Lung-Shen Lin ◽  
Huey-Lang Yang ◽  
...  
Keyword(s):  
Dna Binding ◽  
Epstein Barr Virus ◽  
Binding Protein ◽  
Dna Binding Protein ◽  
Barr Virus ◽  
Epstein Barr

scholarly journals Switch-like control of helicase processivity by single-stranded DNA binding protein

2020 ◽  
Author(s):  
Barbara Stekas ◽  
Masayoshi Honda ◽  
Maria Spies ◽  
Yann R. Chemla
Keyword(s):  
Dna Binding ◽  
Single Molecule ◽  
Molecular Mechanisms ◽  
Binding Protein ◽  
Optical Trap ◽  
Dna Binding Protein ◽  
Single Stranded Dna ◽  
Associated Proteins ◽  
Underlying Mechanisms ◽  
Xpd Helicase

Helicases utilize the energy of NTP hydrolysis to translocate along single-stranded nucleic acids (NA) and unwind the duplex. In the cell, helicases function in the context of other NA-associated proteins which regulate helicase function. For example, single-stranded DNA binding proteins are known to enhance helicase activity, although the underlying mechanisms remain largely unknown. F. acidarmanus XPD helicase serves as a model for understanding the molecular mechanisms of Superfamily 2B helicases, and previous work has shown that its activity is enhanced by the cognate single-stranded DNA binding protein RPA2. Here, single-molecule optical trap measurements of the unwinding activity of a single XPD helicase in the presence of RPA2 reveal a mechanism in which XPD interconverts between two states with different processivities and transient RPA2 interactions stabilize the more processive state, activating a latent “processivity switch” in XPD. These findings provide new insights on mechanisms of helicase regulation by accessory proteins.

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