Regulation of plant phototropic growth by NPH3/RPT2-like substrate phosphorylation and 14-3-3 binding

Sullivan, S. , Waksman, T., Paliogianni, D., Henderson, L., Lütkemeyer, M., Suetsugu, N. and Christie, J. M. (2021) Regulation of plant phototropic growth by NPH3/RPT2-like substrate phosphorylation and 14-3-3 binding. Nature Communications, 12, 6129. (doi: 10.1038/s41467-021-26333-5) (PMID:34675214) (PMCID:PMC8531357)

Abstract

Polarity underlies all directional growth responses in plants including growth towards the light (phototropism). The plasma-membrane associated protein, NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) is a key determinant of phototropic growth which is regulated by phototropin (phot) AGC kinases. Here we demonstrate that NPH3 is directly phosphorylated by phot1 within a conserved C-terminal consensus sequence (RxS) that is necessary to promote phototropism and petiole positioning in Arabidopsis. RxS phosphorylation also triggers 14-3-3 binding combined with changes in NPH3 phosphorylation and localisation status. Mutants of NPH3 that are unable to bind or constitutively bind 14-3-3 s show compromised functionality consistent with a model where phototropic curvature is established by signalling outputs arising from a gradient of NPH3 RxS phosphorylation across the stem. Our findings therefore establish that NPH3/RPT2-Like (NRL) proteins are phosphorylation targets for plant AGC kinases. Moreover, RxS phosphorylation is conserved in other members of the NRL family, suggesting a common mechanism of regulating plant growth to the prevailing light environment.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Suetsugu, Dr Noriyuki and Lutkemeyer, Ms Melanie Katja and Christie, Professor John and Henderson, Ms Louise and Sullivan, Dr Stuart and Paliogianni, Dimitra and Waksman, Thomas
• Authors: Sullivan, S., Waksman, T., Paliogianni, D., Henderson, L., Lütkemeyer, M., Suetsugu, N., and Christie, J. M.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Nature Communications 12: 6129
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
170684		Photoreceptor Engineering to Modulate Plant Growth	John Christie	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/M002128/1	MCSB - Plant Sciences
301413		How do Phototropin Receptor Kinases Initiate Signalling from the Plasma	John Christie	Biotechnology and Biological Sciences Research Council (BBSRC)	BB/R001499/1	Institute of Molecular, Cell & Systems Biology