Premium
Identification and characterization of Ref‐1, a nuclear protein that facilitates AP‐1 DNA‐binding activity.
Author(s) -
Xanthoudakis S.,
Curran T.
Publication year - 1992
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1992.tb05097.x
Subject(s) - biology , dna , nuclear protein , identification (biology) , dna binding protein , computational biology , genetics , microbiology and biotechnology , transcription factor , gene , botany
Fos and Jun form a heterodimeric complex that regulates gene transcription by binding to the activator protein‐1 (AP‐1) DNA sequence motif. Previously, we demonstrated that the DNA‐binding activity of Fos and Jun is regulated in vitro by a novel redox (reduction‐oxidation) mechanism. Reduction of a conserved cysteine (cys) residue in the DNA‐binding domains of Fos and Jun by chemical reducing agents or by a nuclear redox factor stimulates DNA‐binding activity. Here, we describe purification and characterization of a 37 kDa protein (Ref‐1) corresponding to the redox factor. Although Ref‐1 does not bind to the AP‐1 site in association with Fos and Jun, it partially copurifies with a subset of AP‐1 proteins. Purified Ref‐1 protein stimulates AP‐1 DNA‐binding activity through the conserved Cys residues in Fos and Jun, but it does not alter the DNA‐binding specificity of Fos and Jun. Ref‐1 may represent a novel redox component of the signal transduction processes that regulate eukaryotic gene expression.