Examinando por Autor "Li, Lan"
Mostrando 1 - 2 de 2
Resultados por página
Opciones de ordenación
Ítem Arabidopsis RAD23B regulates pollen development by mediating degradation of KRP1(Oxford University Press, 2020-07-06) Li, Lan; Li, Bin; Xie, Chong; Zhang, Teng; Borassi, Cecilia; Estevez, José M.; Li, Xiushan; Liu, XuanmingThe ubiquitin (Ub)/26S proteasome system (UPS) plays a key role in plant growth, development, and survival by directing the turnover of numerous regulatory proteins. In the UPS, the ubiquitin-like (UBL) and ubiquitin-associated (UBA) domains function as hubs for ubiquitin-mediated protein degradation. Radiation sensitive 23 (RAD23), which has been identified as a UBL/UBA protein, contributes to the progression of the cell cycle, stress responses, ER proteolysis, and DNA repair. Here, we report that pollen development is arrested at the microspore stage in a rad23b null mutant. We demonstrate that RAD23B can directly interact with KIP-related protein 1 (KRP1) through its UBL-UBA domains. In addition, plants overexpressing KRP1 have defects in pollen development, which is a phenotype similar to the rad23b mutant. RAD23B promotes the degradation of KRP1 in vivo, which is accumulated following treatment with the proteasome inhibitor MG132. Our results indicate that RAD23B plays an important in pollen development by controlling the turnover of the key cell cycle protein, KRP1.Ítem The RALF1–FERONIA Complex Phosphorylates eIF4E1 to Promote Protein Synthesis and Polar Root Hair Growth(Cell Press, 2020-05-04) Zhu, Sirui; Estévez, José Manuel; Liao, Hongdong; Zhu, Yonghua; Yang, Tao; Li, Chiyu; Wang, Yichuan; Li, Lan; Liu, Xuanming; Pacheco, Javier Martinez; Guo, Hongwei; Yu, FengThe molecular links between extracellular signals and the regulation of localized protein synthesis in plant cells are poorly understood. Here, we show that in Arabidopsis thaliana, the extracellular peptide RALF1 and its receptor, the FERONIA receptor kinase, promote root hair (RH) tip growth by modulating protein synthesis. We found that RALF1 promotes FERONIA-mediated phosphorylation of eIF4E1, a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate. Phosphorylated eIF4E1 increases mRNA affinity and modulates mRNA translation and, thus, protein synthesis. The mRNAs targeted by the RALF1–FERONIA–eIF4E1 module include ROP2 and RSL4, which are important regulators of RH cell polarity and growth. RALF1 and FERONIA are expressed in a polar manner in RHs, which facilitate eIF4E1 polar localization and thus may control local ROP2 translation. Moreover, we demonstrated that high-level accumulation of RSL4 exerts negative-feedback regulation of RALF1 expression by directly binding the RALF1 gene promoter, determining the final RH size. Our study reveals that the link between RALF1–FERONIA signaling and protein synthesis constitutes a novel component regulating cell expansion in these polar growing cells. © 2019 The Author This study found that RALF1 promotes the FERONIA-mediated phosphorylation of eIF4E1, which recognizes the mRNA cap, increases mRNA affinity, and modulates mRNA translation. The mRNAs targeted by the RALF1–FERONIA–eIF4E1 module include the root hair (RH) genes ROP2 and RSL4. Moreover, high levels of RSL4 exert negative-feedback regulation on RALF1 expression by directly binding the RALF1 gene promoter, determining the final RH cell size.