The 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 it...The 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 elF4E1,a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate.Phosphorylated elF4E1 increases mRNA affinity and modulates mRNA translation and,thus,protein synthesis.The mRNAs targeted by the RALF1-FERONIA-elF4E1 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 elF4E1 polar丨ocalization and thus may control local f?OP2 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.展开更多
In eukaryotic cells, protein synthesis is a complex and multi-step process that has several mechanisms to start the translation including cap-dependent and cap-independent initiation. The translation control of eukary...In eukaryotic cells, protein synthesis is a complex and multi-step process that has several mechanisms to start the translation including cap-dependent and cap-independent initiation. The translation control of eukaryotic gene expression occurs principally at the initiation step. In this context, it is critical that the eukaryotic translation initiation factor eIF4E bind to the 7-methylguanosine （m7G） cap present at the 5＇- UTRs of most eukaryotic mRNAs. Combined with other initiation factors, elF4E mediates the mRNA recruitment on ribosomes to start the translation. Moreover, the eIF4E nuclear bodies are involved in the export of specific mRNAs from the nucleus to the cytoplasm. In this review, we focus on the elF4E structure and its physiological functions, and describe the role of eIF4E in cancer development and progression and the current therapeutic strategies to target eIF4E.展开更多
基金grants from the National Natural Science Foundation of China(NSFC-31400232,31871396,31571444)Young Elite Scientist Sponsorship program of CAST(YESS20160001)+1 种基金the Open Research Fund of the State Key Laboratory of Hybrid Rice(Hunan Hybrid Rice Research Center)to F.Y.and from ANPCyT(PICT2016-0132 and PICT2017-0066),ICGEB(CRP/ARG16-03)Instituto Milenio iBio-Iniciativa Cientffica Milenio MINECON to J.M.E.
文摘The 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 elF4E1,a eukaryotic translation initiation factor that plays a crucial role in the control of mRNA translation rate.Phosphorylated elF4E1 increases mRNA affinity and modulates mRNA translation and,thus,protein synthesis.The mRNAs targeted by the RALF1-FERONIA-elF4E1 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 elF4E1 polar丨ocalization and thus may control local f?OP2 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.
文摘In eukaryotic cells, protein synthesis is a complex and multi-step process that has several mechanisms to start the translation including cap-dependent and cap-independent initiation. The translation control of eukaryotic gene expression occurs principally at the initiation step. In this context, it is critical that the eukaryotic translation initiation factor eIF4E bind to the 7-methylguanosine （m7G） cap present at the 5＇- UTRs of most eukaryotic mRNAs. Combined with other initiation factors, elF4E mediates the mRNA recruitment on ribosomes to start the translation. Moreover, the eIF4E nuclear bodies are involved in the export of specific mRNAs from the nucleus to the cytoplasm. In this review, we focus on the elF4E structure and its physiological functions, and describe the role of eIF4E in cancer development and progression and the current therapeutic strategies to target eIF4E.
