Deconstructing and repurposing the light-regulated interplay between Arabidopsis phytochromes and interacting factors.

TitleDeconstructing and repurposing the light-regulated interplay between Arabidopsis phytochromes and interacting factors.
Publication TypeJournal Article
Year of Publication2019
AuthorsGolonka, D, Fischbach, P, Jena, SG, Kleeberg, JRW, Essen, L-O, Toettcher, JE, Zurbriggen, MD, Möglich, A
JournalCommun Biol
Volume2
Pagination448
Date Published2019
ISSN2399-3642
Abstract

Phytochrome photoreceptors mediate adaptive responses of plants to red and far-red light. These responses generally entail light-regulated association between phytochromes and other proteins, among them the phytochrome-interacting factors (PIF). The interaction with Arabidopsis thaliana phytochrome B (AtPhyB) localizes to the bipartite APB motif of the A. thaliana PIFs (AtPIF). To address a dearth of quantitative interaction data, we construct and analyze numerous AtPIF3/6 variants. Red-light-activated binding is predominantly mediated by the APB N-terminus, whereas the C-terminus modulates binding and underlies the differential affinity of AtPIF3 and AtPIF6. We identify AtPIF variants of reduced size, monomeric or homodimeric state, and with AtPhyB affinities between 10 and 700 nM. Optogenetically deployed in mammalian cells, the AtPIF variants drive light-regulated gene expression and membrane recruitment, in certain cases reducing basal activity and enhancing regulatory response. Moreover, our results provide hitherto unavailable quantitative insight into the AtPhyB:AtPIF interaction underpinning vital light-dependent responses in plants.

DOI10.1038/s42003-019-0687-9
Alternate JournalCommun Biol
PubMed ID31815202
PubMed Central IDPMC6888877
Grant ListDP2 EB024247 / EB / NIBIB NIH HHS / United States
T32 GM007388 / GM / NIGMS NIH HHS / United States