Regulation of DNA binding and trans-activation by a xenobiotic stress-activated plant transcription factor

Citation
C. Johnson et al., Regulation of DNA binding and trans-activation by a xenobiotic stress-activated plant transcription factor, J BIOL CHEM, 276(1), 2001, pp. 172-178
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
0021-9258 → ACNP
Volume
276
Issue
1
Year of publication
2001
Pages
172 - 178
Database
ISI
SICI code
0021-9258(20010105)276:1<172:RODBAT>2.0.ZU;2-3
Abstract
As-1-type cis-elements augment transcription of both nuclear and pathogen g enes in response to stress and defense cues in plants. Basic/leucine zipper proteins termed "TGA factors" that specifically bind as-1 elements are lik ely candidates for mediating these transcription activities. Our earlier wo rk has shown that 2,4-dichlorophenoxyacetic acid-induced xenobiotic stress enhances trans-activation by a chimeric fusion protein of the yeast Gal4 bi nding domain and TGA1a, a TGA factor of tobacco. Here we demonstrate that x enobiotic stress also enhances the ability of native TGA1a to bind as-1 and activate transcription of a known target gene. In addition, the previously identified xenobiotic stress-responsive domain of TGA1a was found to inhib it this factor's trans-activation potential by a mechanism that appears to involve stimulus-reversible interactions with a nuclear repressor protein. Results from these and other studies can now be placed in the context of a working model to explain basal and xenobiotic stress-induced activities of TGA1a through its cognate cis-acting element.