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Differential regulation of TGA transcription factors by post‐transcriptional control
Author(s) -
Pontier Dominique,
Privat Isabelle,
Trifa Youssef,
Zhou JunMa,
Klessig Daniel F.,
Lam Eric
Publication year - 2002
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2002.01461.x
Subject(s) - arabidopsis , proteolysis , transcription factor , biology , cauliflower mosaic virus , proteasome , transcription (linguistics) , genetics , fusion protein , ubiquitin , gene , microbiology and biotechnology , biochemistry , transgene , mutant , genetically modified crops , linguistics , philosophy , enzyme , recombinant dna
Summary Transcription factors often belong to multigene families and their individual contribution in a particular regulatory network remains difficult to assess. We show here that specific members from a family of conserved Arabidopsis bZIP transcription factors, the TGA proteins, are regulated in their protein stability by developmental stage‐specific proteolysis. Using GFP fusions of three different Arabidopsis TGA factors that represent members of distinct subclasses of the TGA factor family, we demonstrate that two of these TGA proteins are specifically targeted for proteolysis in mature leaf cells. Using a supershift gel mobility assay, we found evidence for similar regulation of the cognate proteins as compared to the GFP fusion proteins expressed under the cauliflower mosaic virus (CaMV) 35S promoter. Using various inhibitors, we showed that the expression of at least one of these three TGA factors could be stabilized by inhibition of proteasome‐mediated proteolysis. This study indicates that TGA transcription factors may be regulated by distinct pathways of targeted proteolysis that can serve to modulate the contribution of specific members of a multigene family in complex regulatory pathways.