Requirements for selective recruitment of Ets proteins and activation of mb-1/Ig-alpha gene transcription by Pax-5 (BSAP).
Nucleic Acids Res
; 31(19): 5483-9, 2003 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-14500810
ABSTRACT
Pax-5, a member of the paired domain family of transcription factors, is a key regulator of B lymphocyte-specific transcription and differentiation. A major target of Pax-5-mediated activation is the mb-1 gene, which encodes the essential transmembrane signaling protein Ig-alpha. Pax-5 recruits three members of the Ets family of transcription factors Ets-1, Fli-1 and GABPalpha (with GABPbeta1), to assemble ternary complexes on the mb-1 promoter in vitro. Using the Pax-5Ets-1DNA crystal structure as a guide, we defined amino acid requirements for transcriptional activation of endogenous mb-1 genes using a novel cell-based assay. Mutations in the beta-hairpin/beta-turn of the DNA-binding domain of Pax-5 demonstrated its importance for DNA sequence recognition and activation of mb-1 transcription. Mutations of amino acids contacting Ets-1 in the crystal structure reduced or blocked mb-1 promoter activation. One of these mutations, Q22A, resulted in greatly reduced mb-1 gene transcript levels, concurrent with the loss of its ability to recruit Fli-1 to bind the promoter in vitro. In contrast, the mutation had no effect on recruitment of the related Ets protein GABPalpha (with GABPbeta1). These data further define requirements for Pax-5 function in vivo and reveal the complexity of interactions required for cooperative partnerships between transcription factors.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
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Receptores de Antígenos de Linfócitos B
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Antígenos CD
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Ativação Transcricional
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Proteínas de Ligação a DNA
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article