Increasing the dynamics of non-photochemical quenching(NPQ)under changing light levels represents a promising strategy for improving photosynthetic light-use efficiency for greater crop yields.PsbS plays a crucial rol...Increasing the dynamics of non-photochemical quenching(NPQ)under changing light levels represents a promising strategy for improving photosynthetic light-use efficiency for greater crop yields.PsbS plays a crucial role in modulating both the capacity and dynamics of NPQ.Nevertheless,the specific mechanisms by which PsbS mediates functional state transitions and the detailed molecular interactions involved in NPQ are still not fully understood.In this study,we identified an amino acid residue,P132,in Arabidopsis thaliana PsbS(AtPsbS)whose substitution with alanine(P132A)causes rapid NPQ induction under low light and significantly reduces the rate of NPQ relaxation in the dark.Our findings suggest that the AtPsbS P132A mutation keeps PsbS in a loose dimer state that is prone to dissociation and hence causes a reduced proportion of dimers and altered NPQ dynamics.Our study also shows that the AtPsbS P132A+E122Q+E226Q mutant,which lacks protonation-sensing amino acids,may partially induce NPQ even in the absence of protonation,indicating that the structural features of PsbS may independently influence NPQ.Data from this study provide strong evidence that the structural features of PsbS affect NPQ induction and point to a significant role of the PsbS sequence in NPQ dynamics,in addition to the commonly assumed importance of PsbS levels and protonation of E122 and E226 in PsbS.In other words,the protonation sites(i.e.,E122 and E226)and the amino acid residues that alter the structural characteristics of the PsbS protein both have an important effect on its NPQ function.展开更多
For optimum photosynthetic productivity,it is crucial for plants to swiftly transition between light-harvesting and photoprotective states as light conditions change in the field.The PsbS protein plays a pivotal role ...For optimum photosynthetic productivity,it is crucial for plants to swiftly transition between light-harvesting and photoprotective states as light conditions change in the field.The PsbS protein plays a pivotal role in this process by switching the light-harvesting antenna,light-harvesting complex Ⅱ(LHCⅡ),into the photoprotective state,energy-dependent chlorophyll fluorescence quenching(qE),to avoid photoinhibition in high-light environments.However,the molecular mechanism by which PsbS acts upon LHCⅡ has remained unclear.In our study,we identified the specific amino acid domains that are essential for PsbS function.Using amino-acid point mutagenesis of PsbS in vivo,we found that the activation of photoprotection involves dynamic changes in the oligomeric state and conformation of PsbS,with two residues,E67 and E173,playing a key role in this process.Further,the replacement of hydrophobic phenylalanine residues in transmembrane helixes Ⅱ(F83,F84,F87)and Ⅳ(F191,F193,F194)with tyrosine revealed that phenylalanine localized in helix Ⅳ can play a significant role in hydrophobic interactions of PsbS with LHCⅡ.Removal of the 3_(10) helix(H3)amino acids I74,Y75,and E76 did not affect the amplitude but strongly delayed the recovery of qE in darkness.Moreover,an AI-assisted protein-folding evolutionary scale model approach(ESMFold)was adopted to intelligently manipulate protein functions in silico and thus streamline and evaluate experimental point mutagenesis strategies.This provides new insights into the molecular architecture of PsbS that are essential for regulating light harvesting in higher plants.展开更多
电力系统分析综合程序 PSASP( Power System Analysis Software Package)是国内进行电力系统计算和仿真经常使用的软件 ,其结果也为大家所普遍接受。 Mathworks公司新近推出的MATLAB5.2中的 Power System Blockset( PSB)是专门为电力系...电力系统分析综合程序 PSASP( Power System Analysis Software Package)是国内进行电力系统计算和仿真经常使用的软件 ,其结果也为大家所普遍接受。 Mathworks公司新近推出的MATLAB5.2中的 Power System Blockset( PSB)是专门为电力系统设计的仿真分析软件 ,其功能十分强大。文中对 3个电力系统典型模型的潮流和稳定分别进行了计算 ,分析表明这两种电力系统仿真软件得到的结果几乎完全相同 ,但也存在一定的差异 ,对其原因给出了初步的解释 ,并介绍了应用 MATLAB进行电力系统仿真时经常用到的一些方法。展开更多
基金funded by the National Key Research and Development Program(grant number 2020YFA0907600)the Shanghai Science Basic Research Project of Technology Innovation Action Plan(grant number 23JC1403900)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(grant number XDB37020104)the Natural Science Foundation of China(grant numbers T2350011 to Y.Weng,92269102 to Y.Wang and U22A20464 to X.-G.Z.)M.F.was supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB0630101)and the CAS Pioneer Hundred Talents Program.
文摘Increasing the dynamics of non-photochemical quenching(NPQ)under changing light levels represents a promising strategy for improving photosynthetic light-use efficiency for greater crop yields.PsbS plays a crucial role in modulating both the capacity and dynamics of NPQ.Nevertheless,the specific mechanisms by which PsbS mediates functional state transitions and the detailed molecular interactions involved in NPQ are still not fully understood.In this study,we identified an amino acid residue,P132,in Arabidopsis thaliana PsbS(AtPsbS)whose substitution with alanine(P132A)causes rapid NPQ induction under low light and significantly reduces the rate of NPQ relaxation in the dark.Our findings suggest that the AtPsbS P132A mutation keeps PsbS in a loose dimer state that is prone to dissociation and hence causes a reduced proportion of dimers and altered NPQ dynamics.Our study also shows that the AtPsbS P132A+E122Q+E226Q mutant,which lacks protonation-sensing amino acids,may partially induce NPQ even in the absence of protonation,indicating that the structural features of PsbS may independently influence NPQ.Data from this study provide strong evidence that the structural features of PsbS affect NPQ induction and point to a significant role of the PsbS sequence in NPQ dynamics,in addition to the commonly assumed importance of PsbS levels and protonation of E122 and E226 in PsbS.In other words,the protonation sites(i.e.,E122 and E226)and the amino acid residues that alter the structural characteristics of the PsbS protein both have an important effect on its NPQ function.
基金supported by grants funded by a Queen Mary University of London Ph.D.studentship to L.Ca grant from The Leverhulme Trust to A.V.R.
文摘For optimum photosynthetic productivity,it is crucial for plants to swiftly transition between light-harvesting and photoprotective states as light conditions change in the field.The PsbS protein plays a pivotal role in this process by switching the light-harvesting antenna,light-harvesting complex Ⅱ(LHCⅡ),into the photoprotective state,energy-dependent chlorophyll fluorescence quenching(qE),to avoid photoinhibition in high-light environments.However,the molecular mechanism by which PsbS acts upon LHCⅡ has remained unclear.In our study,we identified the specific amino acid domains that are essential for PsbS function.Using amino-acid point mutagenesis of PsbS in vivo,we found that the activation of photoprotection involves dynamic changes in the oligomeric state and conformation of PsbS,with two residues,E67 and E173,playing a key role in this process.Further,the replacement of hydrophobic phenylalanine residues in transmembrane helixes Ⅱ(F83,F84,F87)and Ⅳ(F191,F193,F194)with tyrosine revealed that phenylalanine localized in helix Ⅳ can play a significant role in hydrophobic interactions of PsbS with LHCⅡ.Removal of the 3_(10) helix(H3)amino acids I74,Y75,and E76 did not affect the amplitude but strongly delayed the recovery of qE in darkness.Moreover,an AI-assisted protein-folding evolutionary scale model approach(ESMFold)was adopted to intelligently manipulate protein functions in silico and thus streamline and evaluate experimental point mutagenesis strategies.This provides new insights into the molecular architecture of PsbS that are essential for regulating light harvesting in higher plants.
文摘电力系统分析综合程序 PSASP( Power System Analysis Software Package)是国内进行电力系统计算和仿真经常使用的软件 ,其结果也为大家所普遍接受。 Mathworks公司新近推出的MATLAB5.2中的 Power System Blockset( PSB)是专门为电力系统设计的仿真分析软件 ,其功能十分强大。文中对 3个电力系统典型模型的潮流和稳定分别进行了计算 ,分析表明这两种电力系统仿真软件得到的结果几乎完全相同 ,但也存在一定的差异 ,对其原因给出了初步的解释 ,并介绍了应用 MATLAB进行电力系统仿真时经常用到的一些方法。
