NF-AT5: The NF-AT Family of Transcription Factors Expands in a New Direction

The NF-AT family of transcription factors (nuclearfactor of activated T cells), which is distantly related tothe NF-κB/Rel family, has recently been expanded by thediscovery of a new member, NF-AT5 (López-Rodríguezet al. 1999). NF-AT5 contains an NF-AT-like Rel homology domain, conserves the DNA contact residues of the"conventional" NF-AT proteins, NF-AT1 (p, c2), NFAT2 (c, c1), NF-AT3 (c4), and NF-AT4 (x, c3), and bindsDNA sequences similar to those found in the regulatoryregions of well-characterized NF-AT-dependent genes.However, several features of NF-AT5 are distinct fromthose of NF-AT1-4, consistent with the hypothesis thatNF-AT5 is an outlying member of the NF-AT family. Inthis paper, we discuss NF-AT5 in the context of the NFAT and Rel families of transcription factors and presentinformation about its alternative splicing, its chromosomal localization, and its ability to form dimers (or higherorder associations) in solution...