A circadian clock output functions independently of phyB to sustain daytime PIF3 degradation

• 成果类型: Article
• 署名作者: Liu, Wei; Lowrey, Harper; Xu, Anxu; Leung, Chun Chung; Adamchek, Christopher; He, Jiangman; Du, Juan; Chen, Meng; Gendron, Joshua M.
• 署名单位: Yale University; University of California System; University of California Riverside
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14151
• DOI: 10.1073/pnas.2408322121
• 发表日期: 2024-08-27
• 关键词: phytochrome-interacting factors; affinity purification; shade avoidance; arabidopsis; protein; transcription; photomorphogenesis; phosphorylation; period; genes

摘要

The circadian clock is an endogenous oscillator, and its importance lies in its ability to impart rhythmicity on downstream biological processes, or outputs. Our knowledge of output regulation, however, is often limited to an understanding of transcriptional connections between the clock and outputs. For instance, the clock is linked to plant growth through the gating of photoreceptors via rhythmic transcription of the nodal growth regulators, PHYTOCHROME- INTERACTING FACTORs (PIFs), but the clock's role in PIF protein stability is less clear. Here, we identified a clock- regulated, F- box type E3 ubiquitin ligase, CLOCK- REGULATED F- BOX WITH A LONG HYPOCOTYL 1 (CFH1), that specifically interacts with and degrades PIF3 during the daytime. Additionally, genetic evidence indicates that CFH1 functions primarily in monochromatic red light, yet CFH1 confers PIF3 degradation independent of the prominent red- light photoreceptor phytochrome B (phyB). This work reveals a clock- mediated growth regulation mechanism in which circadian expression of CFH1 promotes sustained, daytime PIF3 degradation in parallel with phyB signaling.