N^(6)-methyladenosine (m^(6)A) is a prevalent internal post-transcriptional modification in eukaryotic RNAs executed by m^(6)A-binding proteins known as “readers.” Our previous research demonstrated that the Arabido...N^(6)-methyladenosine (m^(6)A) is a prevalent internal post-transcriptional modification in eukaryotic RNAs executed by m^(6)A-binding proteins known as “readers.” Our previous research demonstrated that the Arabidopsis m^(6)A reader ECT2 positively regulates transcript levels of the proteasome regulator PTRE1 and several 20S proteasome subunits, thereby enhancing 26S proteasome activity. However, mechanism underlying the selective recognition of m^(6)A targets by readers, such as ECT2, remains elusive. In this study, we further demonstrate that ECT2 physically interacts with PTRE1 and several 20S proteasome subunits. This interaction, which occurs on the ribosome, involves the N terminus of PTRE1, suggesting that ECT2 might bind to the nascent PTRE1 polypeptide. Deleting ECT2’s protein interaction domain impairs its mRNA-binding ability, whereas mutations in the m^(6)A-RNA-binding site do not affect protein-protein interactions. Moreover, introducing a novel protein-binding domain into ECT2 increases transcript levels of proteins interacting with this domain. Our findings indicate that interaction with the PTRE1 protein enhances ECT2’s binding to PTRE1 m^(6)A mRNAs during translation, thereby regulating PTRE1 mRNA levels.展开更多
The coupling region of a Hall thruster with a hollow cathode is the region between the cathode and the thruster plume.The characteristics of plasma in that region are complicated and strongly associated with the thrus...The coupling region of a Hall thruster with a hollow cathode is the region between the cathode and the thruster plume.The characteristics of plasma in that region are complicated and strongly associated with the thruster working conditions and the cathode position.In this paper,a laboratory 100 W class magnetically shielded Hall thruster was coupled with a hollow cathode.Optical imaging and electrostatic probe were employed to monitor and scan the plasma plume.Plume characteristics in the coupling region in non-self-sustained mode and self-sustained mode were compared.Evolution of the coupling plume with the cathode position was studied.Experiments show that,when turning the thruster into self-sustained mode or moving the cathode further away axially,the discharge current can be reduced by 6.4–10.6%restraining the electron current and improving ionization.In particular,when the cathode is moved further,the electron conduction near the channel walls is suppressed.The electron current is reduced by 27.4%and the ion beam current is increased by 7%.Overall,this work shows that the working mode of the thruster and the position of the cathode greatly affect the coupling plasma plume.Both play an important role in improving the utilizations of propellant and current.展开更多
基金Double first-class discipline promotion project(2021B10564001)Laboratory of Lingnan Modern Agriculture Project(NT2021001 and NG2021004).
文摘N^(6)-methyladenosine (m^(6)A) is a prevalent internal post-transcriptional modification in eukaryotic RNAs executed by m^(6)A-binding proteins known as “readers.” Our previous research demonstrated that the Arabidopsis m^(6)A reader ECT2 positively regulates transcript levels of the proteasome regulator PTRE1 and several 20S proteasome subunits, thereby enhancing 26S proteasome activity. However, mechanism underlying the selective recognition of m^(6)A targets by readers, such as ECT2, remains elusive. In this study, we further demonstrate that ECT2 physically interacts with PTRE1 and several 20S proteasome subunits. This interaction, which occurs on the ribosome, involves the N terminus of PTRE1, suggesting that ECT2 might bind to the nascent PTRE1 polypeptide. Deleting ECT2’s protein interaction domain impairs its mRNA-binding ability, whereas mutations in the m^(6)A-RNA-binding site do not affect protein-protein interactions. Moreover, introducing a novel protein-binding domain into ECT2 increases transcript levels of proteins interacting with this domain. Our findings indicate that interaction with the PTRE1 protein enhances ECT2’s binding to PTRE1 m^(6)A mRNAs during translation, thereby regulating PTRE1 mRNA levels.
基金supported by the National Natural Science Foundation of China(No.11872093)。
文摘The coupling region of a Hall thruster with a hollow cathode is the region between the cathode and the thruster plume.The characteristics of plasma in that region are complicated and strongly associated with the thruster working conditions and the cathode position.In this paper,a laboratory 100 W class magnetically shielded Hall thruster was coupled with a hollow cathode.Optical imaging and electrostatic probe were employed to monitor and scan the plasma plume.Plume characteristics in the coupling region in non-self-sustained mode and self-sustained mode were compared.Evolution of the coupling plume with the cathode position was studied.Experiments show that,when turning the thruster into self-sustained mode or moving the cathode further away axially,the discharge current can be reduced by 6.4–10.6%restraining the electron current and improving ionization.In particular,when the cathode is moved further,the electron conduction near the channel walls is suppressed.The electron current is reduced by 27.4%and the ion beam current is increased by 7%.Overall,this work shows that the working mode of the thruster and the position of the cathode greatly affect the coupling plasma plume.Both play an important role in improving the utilizations of propellant and current.
