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A bZIP factor, TRAB1, interacts with VP1 and mediates abscisic acid-induced transcription

Author:
Hobo, T., Kowyama, Y., Hattori, T.
Source:
Proceedings of the National Academy of Sciences of the United States of America 1999 v.96 no.26 pp. 15348-15353
ISSN:
0027-8424
Subject:
transcription factors, protoplasts, messenger RNA, promoter regions, recombinant DNA, complementary DNA, Oryza sativa, transgenic plants, embryo (plant), transcription (genetics), gene expression, binding sites, reporter genes, abscisic acid, roots, beta-glucuronidase, leaves
Abstract:
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.
Agid:
2357673