A trans-acting factor that binds to a GT-motif in a phytochrome gene promoter.
The regulatory photoreceptor, phytochrome, controls the expression of numerous genes, including its own phyA genes, which are transcriptionally repressed in response to light. Functional analysis of a rice phyA gene promoter, by means of microprojectile-mediated gene transfer, indicates that a GT motif, GCGGTAATT, closely related to elements in the promoters of a number of other light-regulated genes, is critical for expression. Partial complementary DNA clones have been obtained for a rice nuclear protein, designated GT-2, that binds in a highly sequence-specific fashion to this motif. Mutational analysis shows that the paired G's are most crucial to binding. GT-2 has domains related to certain other transcription factors. Northern blot analysis shows that GT-2 messenger RNA levels decline in white light although red and far red light pulses are ineffective.
Dehesh
K
K
University of California, Berkeley/U.S. Department of Agriculture, Plant Gene Expression Center, Albany 94710.
Bruce
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Quail
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003850:Deoxyribonuclease I; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D009710:Nucleotide Mapping; D015345:Oligonucleotide Probes; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010834:Phytochrome / Q000235:genetics*; D011401:Promoter Regions, Genetic
D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D010834:Phytochrome; D003850:Deoxyribonuclease I