A family of immunologically related transcription factors that includes multiple forms of ATF and AP-1.

Abstract

ATF is a cellular transcription factor involved in the regulation of multiple adenovirus E1A-and cellular cAMP-inducible promoters. Using DNA affinity chromatography, we have purified ATF and found that a series of polypeptides copurify in a sequence-specific manner. We demonstrate that these polypeptides represent a family of proteins that are related by DNA-binding specificity and by immunological cross-reactivity. This family includes the transcription factor AP-1, whose recognition sequence, GTGAGTCAA, differs from the ATF consensus, GTGACGTCAA, by the absence of a cytosine residue. Our results further indicate that there are multiple forms of both ATF and AP-1. The immunological cross-reactivity and related DNA-binding specificities suggest that ATF and AP-1 contain similar amino acid sequences and may have originated from a common gene.

Purification of DNA-binding transcription factors by their selective adsorption on the affinity latex particles

“…These molecular weights were the same as those of the two ATF forms, reported by Hai et al (7). They have presented evidence for an additional form of ATF (a 47-kD ATF), which is present in HeLa cells in approximately equal abundance to 43-kD ATF, although ATF was identified as a single 43-to 45-kD polypeptide (4,5).…”

“…And they were examined for the ability to purify sequence-specific DNA binding factor, ATF or E4TF3, responsible for transcription of the adenovirus (Ad) early regions, E2, E3 and E4 (2)(3)(4)(5)(6)(7). This factor was quickly and efficiently purified from the extracts of HeLa cells by sequential batch-wise procedures with the affinity latex particles.…”

Negative and positive regulation by transcription factor cAMP response element-binding protein is modulated by phosphorylation.

“…The data with the CREB Ml mutant (Ser-133 -* Ala), which is unable to be phosphorylated by PKA, support the idea that the pleiotropic effect of CREB is controlled by PKA-induced phosphorylation. Hence (37)(38)(39)(40). Whether the binding affinities of these proteins to their cognate DNA-binding sites are different for various members of these families or whether they have differential tissue distribution is yet unknown.…”

c-Jun, at the crossroad of the signaling network

“…The current view of AP-1 is a collective term for dimers formed by proteins of the Jun (c-Jun, JunB and JunD), FosB,Fra1 and Fra2), activating transcription factor (ATF) (ATF2, ATF3/LRF1, B-ATF, JDP1 and JDP2) and musculoaponeurotic fibrosarcoma (MAF) (c-Maf, MafB, MafA, MafG/F/K and Nrl) families (Hai et al, 1988;Angel and Karin, 1991). These are structurally similar and functionally related basic leucine zipper (bZIP) proteins, which form homo-and/or hetero-dimers through the bZIP domain.…”