1: J Biol Chem. 2001 Jan 5;276(1):819-26. 

A set of Hox proteins interact with the Maf oncoprotein to inhibit its DNA
binding, transactivation, and transforming activities.

Kataoka K, Yoshitomo-Nakagawa K, Shioda S, Nishizawa M.

Department of Virology, Institute of Medical Science, University of Tokyo, 4-6-1
Shirokanedai, Minato-ku 108-8639, Tokyo, Japan. kkataoka@bio.titech.ac.jp

Maf oncoprotein is a basic-leucine zipper (bZip) type of transcriptional
activator. Since many transcription factors are known to form functional
complexes, we searched for proteins that interact with the DNA-binding domain of
Maf using the phage display method and identified two homeodomain-containing
proteins, Hoxd12 and MHox/Prx1/Phox1/Pmx1. Studies with mutants of Hox and Maf
proteins showed that they associate through their DNA-binding domains; the
homeodomain of Hox and the bZip domain of Maf, respectively. Reflecting the high
similarity of the bZip domain, all other Maf family members tested (c-/v-Maf,
MafB, MafK, MafF, and MafG) also associated with the Hox proteins. Pax6, whose
homeodomain is relatively similar to MHox, also could interact with Maf.
However, two other bZip oncoproteins, Fos and Jun, failed to associate with the
Hox proteins, while a distantly related Hox family member, Meis1, could not
interact with Maf. Through interactions with the bZip domain, the Hox proteins
inhibited the DNA binding activity of Maf, whereas the binding of Hox proteins
to their recognition sequences was not abrogated by Maf. We further showed that
coexpression of the Hox proteins repressed transcriptional activation and
transforming activity of Maf. These results suggested that the interaction of a
set of Hox proteins with Maf family members may interfere not only with their
oncogenicity but also with their physiological roles.

PMID: 11036080 [PubMed - indexed for MEDLINE]


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