Many small RNAs have been confirmed to play important roles in the development of root nodules and arbuscular mycorrhiza. In this study, we carried out the identification of certain small RNAs in leguminous plants(Med...Many small RNAs have been confirmed to play important roles in the development of root nodules and arbuscular mycorrhiza. In this study, we carried out the identification of certain small RNAs in leguminous plants(Medicago truncatula, soybean, peanut and common bean), such as miRNAs, tRFs and srRNAs, as well as the computational investigation of their regulations. Thirty miRNAs were predicted to be involved in establishing root nodules and mycorrhiza, and 12 of them were novel in common bean and peanut. The generation of tRFs in M. truncatula was not associated with tRNA gene frequencies and codon usage. Six tRFs exhibited different expressions in mycorrhiza and root nodules. Moreover, srRNA^(5.8S) in M. truncatula was generated from the regions with relatively low conservation at the rRNA 3′ terminal. The protein-protein interactions between the proteins encoded by the target genes of miRNAs, tRFs and srRNAs were computed. The regulation of these three types of sRNAs in the symbiosis between leguminous plants and microorganisms is not a single regulation of certain signaling or metabolic pathways but a global regulation for the plants to own growth or specific events in symbiosis.展开更多
Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of...Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of 30 70 residues(termed island domain,ID)have been found in some plant LRR receptor-like kinases(RLKs)and animal Toll-like receptors(TLR7-9).Recent studies provide insight into how a single ID is structurally integrated into an LRR protein.However,structural information on an LRR protein with two IDs is lacking.The receptor-like protein kinase 2(RPK2)is an LRR-RLK and has important roles in controlling plant growth and development by perception and transduction of hormone signal.Here we present the crystal structure of the extracellular LRR domain of RPK2(RPK2-LRR)containing two IDs from Arabidopsis.The structure reveals that both of the IDs are helical and located at the central region of the single RPK2-LRR solenoid.One of them binds to the inner surface of the solenoid,whereas the other one mainly interacts with the lateral side.Unexpectedly,a long loop immediately following the N-terminal capping domain of RPK2-LRR is presented toward and sandwiched between the two IDs,further stabilizing their embedding to the LRR solenoid.A potential ligand binding site formed by the two IDs and the solenoid is located at the C-terminal side of RPK2-LRR.The structural information of RPK2-LRR broadens our understanding toward the large family of LRR proteins and provides insight into RPK2-mediated signaling.展开更多
基金supported by the National Natural Science Foundation of China(31371328,31571366,31470191)the Science and Technology Project of Zhejiang Province(2013C3303,2014C33019)Project of Jiangxi Academy of Science(2014-XTPH1-09,2014-YYB-09)
文摘Many small RNAs have been confirmed to play important roles in the development of root nodules and arbuscular mycorrhiza. In this study, we carried out the identification of certain small RNAs in leguminous plants(Medicago truncatula, soybean, peanut and common bean), such as miRNAs, tRFs and srRNAs, as well as the computational investigation of their regulations. Thirty miRNAs were predicted to be involved in establishing root nodules and mycorrhiza, and 12 of them were novel in common bean and peanut. The generation of tRFs in M. truncatula was not associated with tRNA gene frequencies and codon usage. Six tRFs exhibited different expressions in mycorrhiza and root nodules. Moreover, srRNA^(5.8S) in M. truncatula was generated from the regions with relatively low conservation at the rRNA 3′ terminal. The protein-protein interactions between the proteins encoded by the target genes of miRNAs, tRFs and srRNAs were computed. The regulation of these three types of sRNAs in the symbiosis between leguminous plants and microorganisms is not a single regulation of certain signaling or metabolic pathways but a global regulation for the plants to own growth or specific events in symbiosis.
基金supported by the National Natural Science Foundation of China(31130063)the National Outstanding Young Scholar Science Foundation of China(31025008)to Chai JiJie
文摘Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of 30 70 residues(termed island domain,ID)have been found in some plant LRR receptor-like kinases(RLKs)and animal Toll-like receptors(TLR7-9).Recent studies provide insight into how a single ID is structurally integrated into an LRR protein.However,structural information on an LRR protein with two IDs is lacking.The receptor-like protein kinase 2(RPK2)is an LRR-RLK and has important roles in controlling plant growth and development by perception and transduction of hormone signal.Here we present the crystal structure of the extracellular LRR domain of RPK2(RPK2-LRR)containing two IDs from Arabidopsis.The structure reveals that both of the IDs are helical and located at the central region of the single RPK2-LRR solenoid.One of them binds to the inner surface of the solenoid,whereas the other one mainly interacts with the lateral side.Unexpectedly,a long loop immediately following the N-terminal capping domain of RPK2-LRR is presented toward and sandwiched between the two IDs,further stabilizing their embedding to the LRR solenoid.A potential ligand binding site formed by the two IDs and the solenoid is located at the C-terminal side of RPK2-LRR.The structural information of RPK2-LRR broadens our understanding toward the large family of LRR proteins and provides insight into RPK2-mediated signaling.
