Residues R{sup 199}H{sup 200} of prototype foamy virus transactivator Bel1 contribute to its binding with LTR and IP promoters but not its nuclear localization
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071 (China)
- Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2 (Canada)
Prototype foamy virus encodes a transactivator called Bel1 that enhances viral gene transcription and is essential for PFV replication. Nuclear localization of Bel1 has been reported to rely on two proximal basic motifs R{sup 199}H{sup 200} and R{sup 221}R{sup 222}R{sup 223} that likely function together as a bipartite nuclear localization signal. In this study, we report that mutating R{sup 221}R{sup 222}R{sup 223}, but not R{sup 199}H{sup 200}, relocates Bel1 from the nucleus to the cytoplasm, suggesting an essential role for R{sup 221}R{sup 222}R{sup 223} in the nuclear localization of Bel1. Although not affecting the nuclear localization of Bel1, mutating R{sup 199}H{sup 200} disables Bel1 from transactivating PFV promoters. Results of EMSA reveal that the R{sup 199}H{sup 200} residues are vital for the binding of Bel1 to viral promoter DNA. Moreover, mutating R{sup 199}H{sup 200} in Bel1 impairs PFV replication to a much greater extent than mutating R{sup 221}R{sup 222}R{sup 223}. Collectively, our findings suggest that R{sup 199}H{sup 200} directly participate in Bel1 binding to viral promoter DNA and are indispensible for Bel1 transactivation activity. - Highlights: • The R{sup 221}R{sup 222}R{sup 223} residues are essential for the nuclear localization of Bel1. • Although not affecting the nuclear localization of Bel1, mutating R{sup 199}H{sup 200} disables Bel1 from transactivating PFV promoters. • The R{sup 199}H{sup 200} residues directly participate in Bel1 binding to viral promoter DNA. • Mutating R{sup 199}H{sup 200} in Bel1 impairs PFV replication to a much greater extent than mutating R{sup 221}R{sup 222}R{sup 223}.
- OSTI ID:
- 22435011
- Journal Information:
- Virology, Vol. 449; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0042-6822
- Country of Publication:
- United States
- Language:
- English
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