EBP2, a human protein that interacts with sequences of the Epstein-Barr virus nuclear antigen 1 important for plasmid maintenance

Citation
K. Shire et al., EBP2, a human protein that interacts with sequences of the Epstein-Barr virus nuclear antigen 1 important for plasmid maintenance, J VIROLOGY, 73(4), 1999, pp. 2587-2595
Citations number
60
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF VIROLOGY
ISSN journal
0022538X → ACNP
Volume
73
Issue
4
Year of publication
1999
Pages
2587 - 2595
Database
ISI
SICI code
0022-538X(199904)73:4<2587:EAHPTI>2.0.ZU;2-0
Abstract
The replication and stable maintenance of latent Epstein-Barr virus (EBV) D NA episomes in human cells requires only one viral protein, Epstein-Barr nu clear antigen 1 (EBNA1). To gain insight into the mechanisms by which EBNA1 functions, we used a yeast two-hybrid screen to detect human proteins that interact with EBNA1. We describe here the isolation of a protein, EBP2 (EB NA1 binding protein 2), that specifically interacts with EBNA1. EBP2 was al so shown to bind to DNA-bound EBNA1 in a one-hybrid system, and the EBP2-EB NA1 interaction was confirmed by coimmunoprecipitation from insect cells ex pressing these two proteins. EBP2 is a 35-kDa protein that is conserved in a variety of organisms and is predicted to form coiled-coil interactions. W e have mapped the region of EBNA1 that binds EBP2 and generated internal de letion mutants of EBNA1 that are deficient in EBP2 interactions. Functional analyses of these EBNA1 mutants show that the ability to bind EBP2 correla tes with the ability of EBNA1 to support the long-term maintenance in human cells of a plasmid containing the EBV origin, oriP. An EBNA1 mutant lackin g amino acids 325 to 376 was defective for EBP2 binding and long-term oriP plasmid maintenance but supported the transient replication of oriP plasmid s at wild-type levels. Thus, our results suggest that the EBNA1-EBP2 intera ction is important for the stable segregation of EBV episomes during cell d ivision but not for the replication of the episomes.