title: Enhancement of transactivation activity of Rta of Epstein-Barr virus by RanBPM.
abstract: Epstein-Barr virus (EBV) expresses the immediate-early protein Rta to activate the transcription of EBV lytic genes and the lytic cycle. We show that RanBPM acts as a binding partner of Rta in yeast two-hybrid analysis. The binding was confirmed by glutathione-S-transferase pull-down assay. A coimmunoprecipitation experiment and confocal microscopy revealed that RanBPM and Rta interact in vivo and colocalize in the nucleus. The interaction appears to involve the SPRY domain in RanBPM and the region between amino acid residues 416 to 476 in Rta. The interaction promotes the transactivation activity of Rta in activating the transcription of BMLF1 and p21 in transient transfection assays. Additionally, RanBPM interacts with SUMO-E2 (Ubc9) to promote sumoylation of Rta by SUMO-1. This fact explains why the expression of RanBPM enhances the transactivation activity of Rta. Taken together, the present results indicate a new role of RanBPM in regulating a viral protein that is critical to EBV lytic activation.
authors.affiliation: Institute of Microbiology and Biochemistry, Department of Biochemical Science and Technology, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan. changlk@ntu.edu.tw
authors.forename: Li-Kwan
authors.initials: LK
authors.lastname: Chang
authors.forename: Shih-Tung
authors.initials: ST
authors.lastname: Liu
authors.forename: Chung-Wen
authors.initials: CW
authors.lastname: Kuo
authors.forename: Wen-Hung
authors.initials: WH
authors.lastname: Wang
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Chuang
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Bianchi
authors.forename: Yi-Ren
authors.initials: YR
authors.lastname: Hong
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002460:Cell Line; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D025842:SUMO-1 Protein / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014775:Virus Activation; D020931:ran GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D000098843:Ubiquitin-Conjugating Enzyme UBC9
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C068382:BRLF1 protein, Human herpesvirus 4; C063676:BZLF1 protein, Herpesvirus 4, Human; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D017874:Immediate-Early Proteins; D009687:Nuclear Proteins; C116005:Ran binding protein 9; D011993:Recombinant Fusion Proteins; D025842:SUMO-1 Protein; D015534:Trans-Activators; D014764:Viral Proteins; D044763:Ubiquitin-Conjugating Enzymes; D020931:ran GTP-Binding Protein; D000098843:Ubiquitin-Conjugating Enzyme UBC9