ISSN:
0730-2312
Keywords:
transcription factor
;
activator protein-1
;
protooncogene
;
TPA
;
AP-1
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
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.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240420403
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