FERONIA cytoplasmic domain: node of varied signal outputs

Abstract

The receptor-like kinase (RLK) FERONIA (FER), located on the plasma membrane, belongs to the Catharanthus roseus RLK1-like kinase family (CrRLK1L) and participates in widespread biological processes in plants in a context-dependent fashion. Genetic studies in Arabidopsis illustrated the versatile roles that FER plays in fertilization, vegetative growth, defense and stress responses, cell-wall homeostasis, as well as protein synthesis. These studies also helped to identify genes and signal pathways involved in FER signal transduction. Despite increasingly larger numbers of studies discussing how FER senses its ligand, Rapid alkalinization factor (RALF) peptides, and further regulates downstream factors, few have shown the mechanisms of how FER mediates the specific regulation of downstream signals in context of the phosphorylation of its cytoplasmic domain. As understanding this would help in better understanding the diversity and complexity of FER function, this paper aims to review the roles of FER in regulating different signal outputs from the view of the role of its cytoplasmic domain.

The Receptor Kinase FER Mediates Phase Separation of Glycine-Rich RNA-Binding Protein 7 to Confer Temperature Resilience in Arabidopsis

“…Rapid, effective restoration after short-term extreme cold or heat stress is essential for plant growth. The RALF1-FER module has been widely considered a key node to steer cell growth and is involved in multiple cross-talking signalling pathways, including temperature 35, 57 . FER was recently reported to harbor a temperature-sensitive site (Gly 41) in its extracellular domain, which does not affect its perception to external signals at normal temperatures (20 °C), but abolishes the formation of root hairs at elevated temperatures (30 °C, ref.…”

“…Over 600 RLK genes have been identified in Arabidopsis 31,32 . One such RLKs, FERONIA (FER, from the Catharanthus roseus receptor-like kinase 1-like [CrRLKL1] RLK subfamily), participates in cold responses [33][34][35] . For example, perceiving the low temperature by FER controls Arabidopsis root hair growth 33,36 .…”

New paradigms in cell adaptation: decades of discoveries on the CrRLK1L receptor kinase signalling network

“…The requirement for FER kinase activity is context-specific. A kinase-dead version of FER, harbouring a K565R mutation, can nevertheless phosphorylate its substrates via unknown mechanisms and partially rescue the fer mutant (Kessler et al, 2015;Chakravorty et al, 2018;Haruta et al, 2018) (reviewed by Chen et al, 2020). The FER K565R mutant was also shown to rescue flg22induced FLS2-BAK1 complex formation and the elf18-induced ROS burst, which are both reduced in the fer mutant, suggesting that FER kinase activity is not required for pattern-triggered immunity (PTI) signalling (Gronnier et al, 2020).…”

“…RALF1, FER, and eIF4E1 exhibit a polar localization pattern in root hairs, providing spatial control of Accepted Article localized protein biosynthesis, ultimately determining the final size of root hair cells (Zhu et al, 2020). Importantly, RALF1 expression is downregulated by high levels of RSL4, consequently negatively regulating RALF1-FER-eIF4E1 signalling, and thus generating a negative regulatory feedback loop (Zhu et al, 2020). This module provides a strategy whereby FER is used to both promote cell expansion and determine the final size of cells.…”

Stan: Small Tumor-Aware Network for Breast Ultrasound Image Segmentation

“…It forms the foundation of many image related tasks, such as remote sensing, scene understanding, object tracking, instance and panoptic segmentation, aerospace detection, and image captioning. Chen et al [20] proposed an augmented technique for the R-CNN algorithm with a context model and small region proposal generator; which was the first benchmark dataset for small object detection. Krishna et al [21] designed a Faster R-CNN with a modified upsampling technique to improve the performance of small object detection.…”