A bZIP factor, TRAB1, interacts with VP1 and mediates abscisic acid-induced transcription.
The transcription factor VP1 regulates maturation and dormancy in plant seeds by activating genes responsive to the stress hormone abscisic acid (ABA). Although activation involves ABA-responsive elements (ABREs), VP1 itself does not specifically bind ABREs. Instead, we have identified and cloned a basic region leucine zipper (bZIP) factor, TRAB1, that interacts with both VP1 and ABREs. Transcription from a chimeric promoter with GAL4-binding sites was ABA-inducible if cells expressed a GAL4 DNA-binding domain::TRAB1 fusion protein. Results indicate that TRAB1 is a true trans-acting factor involved in ABA-regulated transcription and reveal a molecular mechanism for the VP1-dependent, ABA-inducible transcription that controls maturation and dormancy in plant embryos.
Hobo
T
T
Center for Molecular Biology, Mie University, 1515 Kamihama-cho, Tsu 514-8507, Japan.
Kowyama
Y
Y
Hattori
T
T
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000502:physiology; D010940:Plant Proteins; D011485:Protein Binding; D020218:Response Elements; D012639:Seeds / Q000235:genetics / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014018:Tissue Distribution; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D010940:Plant Proteins; C403076:TRAB1 protein, plant; D015534:Trans-Activators; D014157:Transcription Factors; D000040:Abscisic Acid