Correlation of transcriptional repression by p21(SNFT) with changes in DNA.NF-AT complex interactions.

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Citation

Bower KE, Zeller RW, Wachsman W, Martinez T, McGuire KL

Correlation of transcriptional repression by p21(SNFT) with changes in DNA.NF-AT complex interactions.

J Biol Chem. 2002 Sep 20;277(38):34967-77. Epub 2002 Jun 26.

PubMed ID
12087103 [ View in PubMed
]
Abstract

p21(SNFT) (21-kDa small nuclear factor isolated from T cells) is a novel human protein of the basic leucine zipper family. The overexpression of p21(SNFT) leads to the significant and specific repression of transcription from the interleukin-2 promoter as well as from several essential activator protein 1 (AP-1)-driven composite promoter elements. One example is the distal nuclear factor of activated T cells (NF-AT)/AP-1 element where the AP-1 (Fos/Jun) basic leucine zipper heterodimer interacts with members of the NF-AT family. p21(SNFT) has been shown to replace Fos in dimerization with Jun on a consensus AP-1 binding site (12-O-tetradecanolyphorbol-13-acetate response element (TRE)) and to interact with Jun and NF-AT at the distal NF-AT/AP-1 enhancer element. A detailed biochemical analysis presented here compares interactions involving p21(SNFT) with those involving Fos. The results demonstrate that a p21(SNFT)/Jun dimer binds a TRE similarly to AP-1 and like AP-1 binds cooperatively with NF-AT at the NF-AT/AP-1 composite element. However, Fos interacts significantly more efficiently than p21(SNFT) with Jun and NF-AT, and the replacement of Fos by p21(SNFT) in the trimolecular complex drastically alters protein-DNA contacts. The data suggest that p21(SNFT) may repress transcriptional activity by inducing a unique conformation in the transcription factor complex.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Transcription factor AP-1P05412Details