Host-derived small RNAs are emerging as critical regulators in the dynamic interactions between host tissues and the microbiome,with implications for microbial pathogenesis and host defense.Among these,transfer RNA-de...Host-derived small RNAs are emerging as critical regulators in the dynamic interactions between host tissues and the microbiome,with implications for microbial pathogenesis and host defense.Among these,transfer RNA-derived small RNAs(tsRNAs)have garnered attention for their roles in modulating microbial behavior.However,the bacterial factors mediating tsRNA interaction and functionality remain poorly understood.In this study,using RNA affinity pull-down assay in combination with mass spectrometry,we identified a putative membrane-bound protein,annotated as P-type ATPase transporter(PtaT)in Fusobacterium nucleatum(Fn),which binds Fn-targeting tsRNAs in a sequence-specific manner.Through targeted mutagenesis and phenotypic characterization,we showed that in both the Fn type strain and a clinical tumor isolate,deletion of ptaT led to reduced tsRNA intake and enhanced resistance to tsRNA-induced growth inhibition.Global RNA sequencing and label-free Raman spectroscopy revealed the phenotypic differences between Fn wild type and PtaT-deficient mutant,highlighting the functional significance of PtaT in purine and pyrimidine metabolism.Furthermore,AlphaFold 3 prediction provides evidence supporting the specific binding between PtaT and Fn-targeting tsRNA.By uncovering the first RNA-binding protein in Fn implicated in growth modulation through interactions with host-derived small RNAs(sRNAs),our study offers new insights into sRNA-mediated host-pathogen interplay within the context of microbiome-host interactions.展开更多
For designing low-impedance magnetic tunnel junctions(MTJs),it has been found that tunneling magnetoresistance strongly correlates with the insulating barrier thickness,imposing a fundamental problem about the relatio...For designing low-impedance magnetic tunnel junctions(MTJs),it has been found that tunneling magnetoresistance strongly correlates with the insulating barrier thickness,imposing a fundamental problem about the relationship between spin polarization of ferromagnet and the insulating barrier thickness in MTJs.Here,we investigate the influence of alumina barrier thickness on tunneling spin polarization(TSP)through a combination of theoretical calculations and experimental verification.Our simulating results reveal a significant impact of barrier thickness on TSP,exhibiting an oscillating decay of TSP with the barrier layer thinning.Experimental verification is realized on FeNi/AlO_(x)/Al superconducting tunnel junctions to directly probe the spin polarization of FeNi ferromagnet using Zeeman-split tunneling spectroscopy technique.These findings provide valuable insights for designs of high-performance spintronic devices,particularly in applications such as magnetic random access memories,where precise control over the insulating barrier layer is crucial.展开更多
基金supported by NSF 2333230 (J.L.),NIH National Institute of Dental and Craniofacial Research (NIDCR) awards,DE030943 (X.H.),DE023810 (X.H.) and DE031329 (J.L.),T90 DE026110,and K99 DE033794 (to P.-T.D.)
文摘Host-derived small RNAs are emerging as critical regulators in the dynamic interactions between host tissues and the microbiome,with implications for microbial pathogenesis and host defense.Among these,transfer RNA-derived small RNAs(tsRNAs)have garnered attention for their roles in modulating microbial behavior.However,the bacterial factors mediating tsRNA interaction and functionality remain poorly understood.In this study,using RNA affinity pull-down assay in combination with mass spectrometry,we identified a putative membrane-bound protein,annotated as P-type ATPase transporter(PtaT)in Fusobacterium nucleatum(Fn),which binds Fn-targeting tsRNAs in a sequence-specific manner.Through targeted mutagenesis and phenotypic characterization,we showed that in both the Fn type strain and a clinical tumor isolate,deletion of ptaT led to reduced tsRNA intake and enhanced resistance to tsRNA-induced growth inhibition.Global RNA sequencing and label-free Raman spectroscopy revealed the phenotypic differences between Fn wild type and PtaT-deficient mutant,highlighting the functional significance of PtaT in purine and pyrimidine metabolism.Furthermore,AlphaFold 3 prediction provides evidence supporting the specific binding between PtaT and Fn-targeting tsRNA.By uncovering the first RNA-binding protein in Fn implicated in growth modulation through interactions with host-derived small RNAs(sRNAs),our study offers new insights into sRNA-mediated host-pathogen interplay within the context of microbiome-host interactions.
基金supported by the National Natural Science Foundation of China(Grant Nos.11774303 and 11574373)the financial support from“15th Graduate Research Innovation Project”from Yunnan Universityfinancial support from the Joint Fund of Yunnan Provincial Science and Technology Department(Grant No.2019FY003008)。
文摘For designing low-impedance magnetic tunnel junctions(MTJs),it has been found that tunneling magnetoresistance strongly correlates with the insulating barrier thickness,imposing a fundamental problem about the relationship between spin polarization of ferromagnet and the insulating barrier thickness in MTJs.Here,we investigate the influence of alumina barrier thickness on tunneling spin polarization(TSP)through a combination of theoretical calculations and experimental verification.Our simulating results reveal a significant impact of barrier thickness on TSP,exhibiting an oscillating decay of TSP with the barrier layer thinning.Experimental verification is realized on FeNi/AlO_(x)/Al superconducting tunnel junctions to directly probe the spin polarization of FeNi ferromagnet using Zeeman-split tunneling spectroscopy technique.These findings provide valuable insights for designs of high-performance spintronic devices,particularly in applications such as magnetic random access memories,where precise control over the insulating barrier layer is crucial.
