FBI-1, a factor that binds to the HIV-1 inducer of short transcripts (IST), is a POZ domain protein.
Nucleic Acids Res
; 27(5): 1251-62, 1999 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-9973611
ABSTRACT
The HIV-1 promoter directs the synthesis of two classes of transcripts, short, non-polyadenylated transcripts and full-length, polyadenylated transcripts. The synthesis of short transcripts is activated by a bipartite DNA element, the inducer of short transcripts or IST, located downstream of the HIV-1 transcriptional start site, while the synthesis of full-length transcripts is activated by the viral activator Tat. Tat binds to the RNA element TAR, which is encoded largely between the two IST half-elements. Upon activation by Tat, the synthesis of short RNAs is repressed. We have previously purified a factor called FBI-1 (for factor that binds to IST) whose binding to wild-type and mutated ISTs correlated well with the abilities of these ISTs to direct the synthesis of short transcripts. Here, we report the cloning of cDNAs encoding FBI-1. FBI-1 contains a POZ domain at its N-terminus and four Krüppel-type zinc fingers at its C-terminus. The C-terminus is sufficient for specific binding, and FBI-1 can form homomers through its POZ domain and, in vivo, through its zinc finger domain as well. In addition, FBI-1 associates with Tat, suggesting that repression of the short transcripts by Tat may be mediated through interactions between the two factors.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
RNA Mensageiro
/
HIV-1
/
Proteínas de Ligação a DNA
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article