QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 13 August 2008
doi: 10.1242/dev.026377

This Article Figures Only Full Text Full Text (PDF) All Versions of this Article: dev.026377v1 135/18/3093    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Yamada, Y. Articles by Williams, J. G. PubMed PubMed Citation Articles by Yamada, Y. Articles by Williams, J. G.

A new family of transcription factors

Yoko Yamada^*, Hong Yu Wang^*, Masashi Fukuzawa, Geoffrey J. Barton and Jeffrey G. Williams

School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.

Author for correspondence (e-mail: j.g.williams{at}dundee.ac.uk)

Accepted 3 July 2008

CudA, a nuclear protein required for Dictyostelium prespore-specific gene expression, binds in vivo to the promoter of the cotC prespore gene. A 14 nucleotide region of the cotC promoter binds CudA in vitro and ECudA, an Entamoeba CudA homologue, also binds to this site. The CudA and ECudA DNA-binding sites contain a dyad and, consistent with a symmetrical binding site, CudA forms a homodimer in the yeast two-hybrid system. Mutation of CudA binding sites within the cotC promoter reduces expression from cotC in prespore cells. The CudA and ECudA proteins share a 120 amino acid core of homology, and clustered point mutations introduced into two highly conserved motifs within the ECudA core region decrease its specific DNA binding in vitro. This region, the presumptive DNA-binding domain, is similar in sequence to domains in two Arabidopsis proteins and one Oryza protein. Significantly, these are the only proteins in the two plant species that contain an SH2 domain. Such a structure, with a DNA-binding domain located upstream of an SH2 domain, suggests that the plant proteins are orthologous to metazoan STATs. Consistent with this notion, the DNA sequence of the CudA half site, GAA, is identical to metazoan STAT half sites, although the relative positions of the two halves of the dyad are reversed. These results define a hitherto unrecognised class of transcription factors and suggest a model for the evolution of STATs and their DNA-binding sites.

Key words: Dictyostelium, CudA, Amoeboza, Plant STATs, SH2 domains