Diverse signaling proteins recruit RCC1-Like Domain proteins to the plasma membrane through a common structural framework.
- 1National Institute for Basic Biology
Abstract
Plants translate diverse environmental cues into spatially regulated growth responses through intracellular signaling mechanisms that remain incompletely understood. Here, we identify the BREVIS RADIX (BRX) domain of RCC1-LIKE DOMAIN (RLD) proteins as a versatile interaction module that recognizes multiple signaling proteins in Arabidopsis. We identified members of the PHYTOCHROME KINASE SUBSTRATE (PKS) and BIG GRAIN (BG) families as novel RLD interactors families, in addition to the previously characterized LAZY1-LIKE (LZY) proteins and BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL). Structural, biochemical, and cell-based analyses demonstrate that these diverse partners, despite having divergent interaction sequences, bind a common surface on the RLD BRX domain to recruit RLD to the plasma membrane. This interaction relies on a shared {beta}-strand-based recognition mode, in which distinct peptide conformations accommodate binding to the same BRX-domain surface. Furthermore, we show that RLD2 and RLD3 contribute to hypocotyl phototropism, and that disrupting the conserved PKS interaction motif abolishes PKS4 function in this response. Together, our findings identify the RLD BRX domain as a molecular platform for diverse protein interactions and establish a PKS-RLD module that operates in phototropism. Furthermore, these findings strongly suggest that RLD recruitment to the plasma membrane via PKS underlies phototropic signal transduction.
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BibTeX
@misc{nishimura2026diverse,
title = {{Diverse signaling proteins recruit RCC1-Like Domain proteins to the plasma membrane through a common structural framework.}},
author = {T. Nishimura and Y. Hirano and A. L. Vazquez and M. Trevisan and P. Sabol and J. Dong and T. Hakoshima and C. Fankhauser and M. T. Morita},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.09.757958},
url = {https://www.biorxiv.org/content/10.64898/2026.10.09.757958v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Diverse signaling proteins recruit RCC1-Like Domain proteins to the plasma membrane through a common structural framework.
AU - T. Nishimura
AU - Y. Hirano
AU - A. L. Vazquez
AU - M. Trevisan
AU - P. Sabol
AU - J. Dong
AU - T. Hakoshima
AU - C. Fankhauser
AU - M. T. Morita
PY - 2026
DA - 2026/10/09
PB - bioRxiv
DO - 10.64898/2026.10.09.757958
UR - https://www.biorxiv.org/content/10.64898/2026.10.09.757958v1
AB - Plants translate diverse environmental cues into spatially regulated growth responses through intracellular signaling mechanisms that remain incompletely understood. Here, we identify the BREVIS RADIX (BRX) domain of RCC1-LIKE DOMAIN (RLD) proteins as a versatile interaction module that recognizes multiple signaling proteins in Arabidopsis. We identified members of the PHYTOCHROME KINASE SUBSTRATE (PKS) and BIG GRAIN (BG) families as novel RLD interactors families, in addition to the previously characterized LAZY1-LIKE (LZY) proteins and BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL). Structural, biochemical, and cell-based analyses demonstrate that these diverse partners, despite having divergent interaction sequences, bind a common surface on the RLD BRX domain to recruit RLD to the plasma membrane. This interaction relies on a shared {beta}-strand-based recognition mode, in which distinct peptide conformations accommodate binding to the same BRX-domain surface. Furthermore, we show that RLD2 and RLD3 contribute to hypocotyl phototropism, and that disrupting the conserved PKS interaction motif abolishes PKS4 function in this response. Together, our findings identify the RLD BRX domain as a molecular platform for diverse protein interactions and establish a PKS-RLD module that operates in phototropism. Furthermore, these findings strongly suggest that RLD recruitment to the plasma membrane via PKS underlies phototropic signal transduction.
ER -