title: Arabidopsis transcription factor ELONGATED HYPOCOTYL5 plays a role in the feedback regulation of phytochrome A signaling.
abstract: Phytochrome A (phyA) is the primary photoreceptor responsible for perceiving and mediating various responses to far-red light in Arabidopsis thaliana. FAR-RED ELONGATED HYPOCOTYL1 (FHY1) and its homolog FHY1-LIKE (FHL) are two small plant-specific proteins essential for light-regulated phyA nuclear accumulation and subsequent phyA signaling processes. FHY3 and its homolog FAR-RED IMPAIRED RESPONSE1 (FAR1) are two transposase-derived transcription factors that directly activate FHY1/FHL transcription and thus mediate subsequent phyA nuclear accumulation and responses. Here, we report that ELONGATED HYPOCOTYL5 (HY5), a well-characterized bZIP transcription factor involved in promoting photomorphogenesis, directly binds ACGT-containing elements a few base pairs away from the FHY3/FAR1 binding sites in the FHY1/FHL promoters. We demonstrate that HY5 physically interacts with FHY3/FAR1 through their respective DNA binding domains and negatively regulates FHY3/FAR1-activated FHY1/FHL expression under far-red light. Together, our data show that HY5 plays a role in negative feedback regulation of phyA signaling by attenuating FHY3/FAR1-activated FHY1/FHL expression, providing a mechanism for fine-tuning phyA signaling homeostasis.
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agro-Biotechnology, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Jigang
authors.initials: J
authors.lastname: Li
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Shumin
authors.initials: S
authors.lastname: Gao
authors.forename: Cristina
authors.initials: C
authors.lastname: Martinez
authors.forename: Guangming
authors.initials: G
authors.lastname: He
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Zhou
authors.forename: Xi
authors.initials: X
authors.lastname: Huang
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Huiyong
authors.initials: H
authors.lastname: Zhang
authors.forename: Yunping
authors.initials: Y
authors.lastname: Shen
authors.forename: Haiyang
authors.initials: H
authors.lastname: Wang
authors.forename: Xing Wang
authors.initials: XW
authors.lastname: Deng
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010834:Phytochrome / Q000235:genetics / Q000378:metabolism; D051942:Phytochrome A / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; C120919:FAR1 protein, Arabidopsis; C441269:FHY1 protein, Arabidopsis; C452847:FHY3 protein, Arabidopsis; C109254:HY5 protein, Arabidopsis; D009687:Nuclear Proteins; D051942:Phytochrome A; D010834:Phytochrome