A transcriptional activation domain of ATMYB2, a drought-inducible Arabidopsis Myb-related protein.

Abstract

Trans-activation activity of ATMYB2, a drought-inducible Myb-related protein in Arabidopsis thaliana, was analyzed using a transient assay of Arabidopsis leaf protoplasts. ATMYB2 activated the transcription of a reporter gene from the MYB-binding site in a sequence-specific manner. Deletion of the C-terminal region of ATMYB2 reduced the trans-activation of the reporter gene, indicating that the acidic region at the C-terminus of ATMYB2 is required for transcriptional activation. The domain exchange analysis with the yeast GAL4 revealed that the C-terminal acidic region of ATMYB2 contains a sufficient domain for trans-activation. These results indicate that ATMYB2 acts as a transcriptional activator and that the C-terminal acidic region of ATMYB2 can function as a transcriptional activation domain.