Functional organization of the Bel-1 trans activator of human foamy virus.
Journal Article (Journal Article)
Human foamy virus encodes a 300-amino-acid nuclear regulatory protein termed Bel-1 that is required for human foamy virus replication in culture. Bel-1 is a potent trans-activator of gene expression directed by the homologous HFV long terminal repeat as well as the long terminal repeat of human immunodeficiency virus type 1. We have used mutational analysis to define several discrete functional domains within Bel-1. The C-terminal approximately 50 amino acids of Bel-1 are shown to be essential for Bel-1 activity but can be effectively substituted by the C-terminal activation domain of VP16. We therefore conclude that the Bel-1 C terminus forms part of an activation domain. Mutations within a central, approximately 100-amino-acid segment of Bel-1 preclude trans-activation by either Bel-1 or the Bel-1/VP16 chimera. These sequences are therefore proposed to direct the interaction of Bel-1 with its viral DNA target sequences. A short Bel-1 segment located between the activation and binding domains is shown to mediate the nuclear localization of this regulatory protein. Although the functional organization of Bel-1 therefore appears comparable to that reported for other eukaryotic transcriptional activators, Bel-1 does not contain sequences homologous to known transcriptional activation or DNA-binding motifs.
Full Text
Duke Authors
Cited Authors
- He, F; Sun, JD; Garrett, ED; Cullen, BR
Published Date
- April 1993
Published In
Volume / Issue
- 67 / 4
Start / End Page
- 1896 - 1904
PubMed ID
- 8383217
Pubmed Central ID
- PMC240257
International Standard Serial Number (ISSN)
- 0022-538X
Digital Object Identifier (DOI)
- 10.1128/JVI.67.4.1896-1904.1993
Language
- eng
Conference Location
- United States