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DNA‐binding activity of jun is increased through its interaction with Fos
Author(s) -
Allegretto Elizabeth A.,
Smeal Tod,
Angel Peter,
Spiegelman Bruce M.,
Karin Michael
Publication year - 1990
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240420403
Subject(s) - microbiology and biotechnology , dna , transcription factor , fusion protein , transcription (linguistics) , hela , binding site , dna binding domain , biology , chemistry , gene , recombinant dna , biochemistry , cell , linguistics , philosophy
Transcription factor AP‐1 mediates induction of a set of genes in response to the phorbol ester tumor promoter TPA. Recently, AP‐I preparations from HeLa cells were shown to contain a product of the c‐JUN protooncogene (Jun/AP‐l) which forms a tight complex with the Fos protein. In this paper, we examine the role of the Fos protein in the DNA‐binding activity of the AP‐I complex. We show that the DNA‐binding activity of bacterially expressed trpE‐Jun fusion proteins is increased many‐fold upon their interaction with Fos (or a Fos‐relaied antigen) expressed from a baculovirus vector. The site of Fos interaction is within the DNA‐binding domain of Jun/AP‐l, and anti‐Fos antibodies interfere with the binding of affinity purified AP‐1 to DNA. These results suggest that, by associating with Jun/AP‐l, Fos is responsible for the formation of a multimeric protein complex that has greater affinity for the target sequence than does Jun/AP‐l alone.