Identification of a C/EBP-Rel complex in avian lymphoid cells.

AUTOR(ES)

Diehl, J A

RESUMO

Protein-protein interactions between the CCAAT box enhancer-binding proteins (C/EBP) and the Rel family of transcription factors have been implicated in the regulation of cytokine gene expression. We have used sequence-specific DNA affinity chromatography to purify a complex from avian T cells that binds to a consensus C/EBP motif. Our results provide evidence that Rel-related proteins are components of the C/EBP-DNA complex as a result of protein-protein interactions with the C/EBP proteins. A polyclonal antiserum raised against the Rel homology domain of v-Rel and antisera raised against two human RelA-derived peptides specifically induced a supershift of the C/EBP-DNA complex in mobility shift assays using the affinity-purified C/EBP. In addition, several kappa B-binding proteins copurified with the avian C/EBP complex through two rounds of sequence-specific DNA affinity chromatography. The kappa B-binding proteins are distinct from the C/EBP proteins that directly contact DNA containing the C/EBP binding site. The identification of a protein complex that binds specifically to a consensus C/EBP site and contains both C/EBP and Rel family members suggests a novel mechanism for regulation of gene expression by Rel family proteins.

Documentos Relacionados

• Regulation of avian leukosis virus long terminal repeat-enhanced transcription by C/EBP-Rel interactions.
• Rearrangements of chicken immunoglobulin genes in lymphoid cells transformed by the avian retroviral oncogene v-rel.
• Avian reticuloendotheliosis virus-transformed lymphoid cells contain multiple pp59v-rel complexes.
• Localization of the v-rel protein in reticuloendotheliosis virus strain T-transformed lymphoid cells.
• Two distinct mechanisms contribute to the constitutive activation of RelB in lymphoid cells.