小柯机器人

美国马萨诸塞大学Alice Y. Cheung等研究人员合作发现，细胞外果胶-RALF相分离介导FERONIA的全局信号功能。2023年12月28日，《细胞》杂志在线发表了这项成果。

研究人员以信号诱导的细胞表面反应为重点，发现内在无序的RALF会引发其同源受体的聚集和内吞，以及FERONIA（FER）和LLG1依赖性的非同源调控因子的内吞，从而广泛影响下游反应。然而，RALF仍处于细胞外。研究人员证明RALF与细胞壁多糖果胶结合。它们相分离并将FER和LLG1募集到果胶-RALF-FER-LLG1凝聚物中，从而启动RALF触发的细胞表面反应。

研究人员进一步发现，盐分升高和温度升高这两种经常遇到的环境挑战会触发RALF-果胶相分离、杂散受体聚集和大量内吞，而且这一过程对于从应激诱导的生长衰减中恢复至关重要。这些研究结果证明，RALF-果胶相分离介导了一种外骨骼机制，以广泛激活依赖于FER-LLG1的细胞表面反应，从而介导FER在植物生长和存活中的整体作用。

据悉，FER-LLG1共受体及其多肽配体RALF调节着植物生长和存活的无数过程。

附：英文原文

Title: Extracellular pectin-RALF phase separation mediates FERONIA global signaling function

Author: Ming-Che James Liu, Fang-Ling Jessica Yeh, Robert Yvon, Kelly Simpson, Samuel Jordan, James Chambers, Hen-Ming Wu, Alice Y. Cheung

Issue&Volume: 2023-12-28

Abstract: The FERONIA (FER)-LLG1 co-receptor and its peptide ligand RALF regulate myriad processesfor plant growth and survival. Focusing on signal-induced cell surface responses,we discovered that intrinsically disordered RALF triggers clustering and endocytosisof its cognate receptors and FER- and LLG1-dependent endocytosis of non-cognate regulatorsof diverse processes, thus capable of broadly impacting downstream responses. RALF,however, remains extracellular. We demonstrate that RALF binds the cell wall polysaccharidepectin. They phase separate and recruit FER and LLG1 into pectin-RALF-FER-LLG1 condensatesto initiate RALF-triggered cell surface responses. We show further that two frequentlyencountered environmental challenges, elevated salt and temperature, trigger RALF-pectinphase separation, promiscuous receptor clustering and massive endocytosis, and thatthis process is crucial for recovery from stress-induced growth attenuation. Our resultssupport that RALF-pectin phase separation mediates an exoskeletal mechanism to broadlyactivate FER-LLG1-dependent cell surface responses to mediate the global role of FERin plant growth and survival.

DOI: 10.1016/j.cell.2023.11.038

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)01324-7