The transcriptional activation domain of the plant-specific Dof1 factor functions in plant, animal, and yeast cells.
Maize Dof1, one of the plant-specific Dof transcription factors, is involved in light-regulated gene expression. To elucidate the molecular mechanism underlying the activity of Dof1, in vivo functional analyses were carried out using transient expression assays with maize mesophyll protoplasts. The results suggest that the Dof domain alone, the region conserved among Dof factors, can mediate interaction with DNA in vivo and distinct Dof1 activities in greening and etiolated protoplasts. A region rich in basic amino acids was identified as a nuclear localization signal. Deletion analysis defined the transcriptional activation domain of 48 amino acids located in the C-terminus of Dof1. This activation domain was also found to be functional in both human cells and yeast, implying that Dof1 may stimulate transcription through a mechanism evolutionarily conserved among eukaryotes. A computer homology search with known transcription factors revealed that the activation domain of Dof1 displayed only a limited similarity to Activation domain II of animal transcription factor GATA-4. Mutational analysis revealed the critical role of a tryptophan residue within the activation domain of Dof1, as had been shown in Activation domain II of GATA-4.
Yanagisawa
S
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Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902 Japan.
D000595:Amino Acid Sequence; D000818:Animals; D029681:Arabidopsis Proteins; D001665:Binding Sites; D002467:Cell Nucleus / Q000737:chemistry; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004247:DNA / Q000378:metabolism; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D050991:GATA4 Transcription Factor; D005786:Gene Expression Regulation; D015966:Gene Expression Regulation, Fungal; D018506:Gene Expression Regulation, Plant; D006801:Humans; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014364:Tryptophan / Q000378:metabolism; D015003:Yeasts / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D029681:Arabidopsis Proteins; C407526:DAG1 protein, Arabidopsis; D004268:DNA-Binding Proteins; D050991:GATA4 Transcription Factor; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014364:Tryptophan; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase