Peptidoglycan recognition proteins （PGRPs） are a family of innate immune receptors that specifically recognize peptidoglycans （PGNs） on the surface of a number of pathogens. Here, we have identified and characteri...Peptidoglycan recognition proteins （PGRPs） are a family of innate immune receptors that specifically recognize peptidoglycans （PGNs） on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator （MmePGRPs）. To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown ofMmePGRP-S1. The knockdown of MmePGRP-S1 （iMmePGRP-S1） dramatically affected wasps＇ survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S 1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.展开更多
Protein recognition using host-vip recognition approach is of great interest but has been limited mainly to the protein N-terminal residues.Here,we site-specific incorporated two novel non-canonical amino acids cont...Protein recognition using host-vip recognition approach is of great interest but has been limited mainly to the protein N-terminal residues.Here,we site-specific incorporated two novel non-canonical amino acids containing supramolecular vip motifs into protein via an expanded genetic code.Through Staudinger reduction reactions,the encoded unnatural residues on protein becoming activated and can be specifically recognized by cucurbit[7]uril(CB[7])and cucurbit[8]uril(CB[8]).We demonstrated that enzyme containing vip amino acid incorporated near the active site can be reversibly regulated by CB[7]recognition,and CB[8]recognition induces protein dimerization.These amino acids will make useful addition to the supramolecular toolbox for protein targeting using molecular recognition approaches.展开更多
This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e....This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.,covalent crosslinking and dynamic reversible crosslinking).The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA,and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA.Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA.Moreover,the N-isopropyl acrylamide(NIPAM)and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively.Therefore,the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H.As a result,the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light.This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins.展开更多
Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned ...Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned in the lower vertebrate species Xenopus tropicalis（Xt）.The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP.The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb.During embryonic development,XtPGRP-L was not expressed until the 72 h tadpole stage.In adult tissues,it was strongly expressed in the liver,lung,intestine,and stomach.Furthermore,after LPS stimulation,the expression of XtPGRP-L was up-regulated significantly in the liver,intestine and spleen,indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.展开更多
Thermoresponsive biotinylated dendronized copolymers carrying dendritic oligoethylene glycol（OEG）pendants were prepared via free radical polymerization,and their protein recognitions based on biotin-avidin interacti...Thermoresponsive biotinylated dendronized copolymers carrying dendritic oligoethylene glycol（OEG）pendants were prepared via free radical polymerization,and their protein recognitions based on biotin-avidin interaction investigated.Both first（PG1） and second generation（PG2） dendronized copolymers were designed to examine possible thickness effects on the interaction between biotin and avidin.Inherited from the outstanding thermoresponsive properties from OEG dendrons,these biotinylated cylindrical copolymers show characteristic thermoresponsive behavior which provides an envelope to capture avidin through switching temperatures above or below their phase transition temperatures（T_（cp）s）.Thus,the recognition of polymer-supported biotin with avidin was investigated with UV/vis spectroscopy and dynamic laser light scattering.In contrast to the case for PG1,the increased thickness for copolymer PG2 hinders partially and inhibits the recognition of biotin moieties with avidin either below or above its T_（cp）.This demonstrates the significant architecture effects from dendronized polymers on the biotin moieties to shift onto periphery of the collapsed aggregates,which should be a prerequisite for protein recognition.These kinds of novel thermoresponsive copolymers may pave a way for the interesting biological applications in areas such as reversible activity control of enzyme or proteins,and for controlled delivery of drugs or genes.展开更多
Peptidoglycan recognition protein(PGRP)plays a vital role in invertebrate innate immunity system as a specific pattern recognition receptor for peptidoglycan.Bivalves possess various PGRP systems for self-defense;howe...Peptidoglycan recognition protein(PGRP)plays a vital role in invertebrate innate immunity system as a specific pattern recognition receptor for peptidoglycan.Bivalves possess various PGRP systems for self-defense;however,it has not been characterized in razor clam Sinonovacula constricta.In this study,eight PGRP coding sequences were identified and analyzed from S.constricta genome,which are designated as ScPGRP-S1,ScPGRP-S2,ScPGRP-S3,ScPGRP-S4,ScPGRP-S5,ScPGRP-S6,ScPGRP-S7,ScPGRP-S8.The results of molecular evolutionary analyses showed that all eight ScPGRP genes were highly conserved and exhi-bited a typical PGRP/amidase_2 domain as PGRP genes in other mollusks.Moreover,the presence of signal peptides was predicted in ScPGRP-S2,ScPGRP-S3 and ScPRP-S6,while a transmembrane structure only existed in ScPGRP-S6.Notably,a tertiary struc-ture analysis indicated that no disulfide bond was observed in ScPGRP-S5 and ScPGRP-S7.The mRNA transcripts analysis of ScPGRPs revealed that the high expression patterns of ScPGRP-S1 and ScPGRP-S4 were found in mantle,adductor muscle and foot,while those of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 were observed in hepatopancreas.Furthermore,the temporal expression profiles of ScPGRPs in the hepatopancreas were analyzed by qPCR<https://www.sciencedirect.com/topics/immunology-and-microbiology/real-time-polymerase-chain-reaction>after Gram-negative Vibrio parahaemolyticus and Gram-positive Staphylococcus aureus challenges.The mRNA expressions of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 could be induced by V.pa-rahaemolyticus and S.aureus.Overall,our findings indicated that ScPGRPs were involved in the immune defense against invaders,which constituted a comprehensive understanding of the potential role of PGRP genes in S.constricta.展开更多
The interaction of the novel tetra-carboxylphenyl calix[4]arene （TCPC） with the bovine heart cytochrome c （Cc） was first investigated by fluorescence spectroscopy and molecular modeling methods. The formation of a...The interaction of the novel tetra-carboxylphenyl calix[4]arene （TCPC） with the bovine heart cytochrome c （Cc） was first investigated by fluorescence spectroscopy and molecular modeling methods. The formation of a stable 1：1 complex was monitored by fluorescence titration, and its binding constant is 1.916 ×10^7 L mol^-1. Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface, that is, the electrostatic interaction drives TCPC to the Cc surface, and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.展开更多
With the support by the National Natural Science Foundation of China,a study led by Prof.Lu Boxun(鲁伯埙)from Fudan University demonstrates that a toxic mutant HTT species is resistant to selective autophagy,revealing...With the support by the National Natural Science Foundation of China,a study led by Prof.Lu Boxun(鲁伯埙)from Fudan University demonstrates that a toxic mutant HTT species is resistant to selective autophagy,revealing the fundamental mechanism of Huntington’s Disease.The study was published展开更多
Trained immunity is essential for innate immune cells to retain a memory of previously encountered pathogens,strengthening the hosts’response against these pathogens.However,the mechanisms governing trained immunity ...Trained immunity is essential for innate immune cells to retain a memory of previously encountered pathogens,strengthening the hosts’response against these pathogens.However,the mechanisms governing trained immunity have not been well elucidated.In this study,flies of different genotypes were trained with heat-killed gram-negative(G)bacteria and subsequently reinfected with live pathogens.The innate immune responses against reinfection were evaluated through assessments of survival rates,antimicrobial peptide expression levels,and bacterial loads,complemented by transcriptomic and chromatin immunoprecipitation(ChIP)analyses.We found that flies trained with heat-killed gram-negative bacteria exhibited a higher survival rate upon secondary infection compared to unprimed flies,which was associated with increased expression of antimicrobial peptides.Priming with Gbacteria increased the sensitivity of the immune deficiency pathway to a second bacterial infection owing to lower levels of peptidoglycan recognition protein SC(PGRP-SC)after the first infection.The gut was the major tissue involved in the downregulation of PGRP-SC expression.The histone H3 lysine 9 trimethylation(H3K9me3)levels were higher at the PGRP-SC loci in immune-trained flies compared to untrained flies,contributing to the suppression of PGRP-SC expression.PGRP-SC overexpression in the fly gut abolished the effect of trained immunity.Taken together,our studies identify an innate immune memory in Drosophila that is regulated by gut-derived PGRP-SC through H3K9me3-mediated epigenetic repression of the PGRP-SC.展开更多
The β-1,3-glucan recognition protein gene from Spodoptera exigua （SeβGRP） was cloned and characterized. The cDNA of this gene is 1？644 nucleotides in length and the predicted polypeptide is 491 amino acids （aa）...The β-1,3-glucan recognition protein gene from Spodoptera exigua （SeβGRP） was cloned and characterized. The cDNA of this gene is 1？644 nucleotides in length and the predicted polypeptide is 491 amino acids （aa） in length, with a calculated molecular mass of 54.8 kDa. The first 22 aa encode a predicted secretion signal peptide. A BLAST search, multiple sequence alignment, and phylogenetic analysis of the aa sequence of SeβGRP revealed that this protein is most similar to the β-1,3-glucan recognition protein （βGRP） family of pattern recognition proteins. Using reverse-transcription polymerase chain reaction, we detected the presence of SeβGRP transcripts in the egg, larval, pupal, and adult stages of S. exigua. In addition, the SeβGRP transcript was expressed in all the tissues examined including the brain, hemocytes, fat body, intestine, and cuticle. There were no changes in SeβGRP mRNA levels in larvae infected with ultraviolet （UV）-killed Escherichia coli DH5α compared with the control larvae inoculated with the water; however, SeβGRP mRNA levels were markedly elevated 4–8 h after infection and slightly induced 12–24 h after infection in larvae injected with UV-killed Fusarium oxysporum. This may be because β-1,3-glucan is the main component of the cell wall of F. oxysporum, but not E. coli DH5α.展开更多
Peptidoglycan recognition proteins(PGRPs)are a class of molecules that play a critical role in insect immunity.Understanding the function of PGRPs is important to improve the efficiency of microbial insecticides.In th...Peptidoglycan recognition proteins(PGRPs)are a class of molecules that play a critical role in insect immunity.Understanding the function of PGRPs is important to improve the efficiency of microbial insecticides.In this study,we investigated the role of PGRP-LB(a long type PGRP)in insect immunity against viruses using Spodoptera exigua and Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV)as an insect-virus model.We cloned and identified a PGRP-LB gene from S.exigua;the gene consisted of 7 exons that encoded a polypeptide of 234 amino acids with a signal peptide and a typical amidase domain.Expression analysis revealed that the abundance of SePGRP-LB transcripts in the fat body was greater than in other tissues.Overexpression of SePGRP-LB resulted in a significant decrease of 49%in the rate of SeMNPV-infected cells.In addition,the multiplication of SeMNPV was significantly decreased:a decrease of 79%in the production of occlusion-derived virion(ODV),and a maximum decrease of 50%in the production of budded virion(BV).In contrast,silencing of SePGRP-LB expression by RNA interference resulted in a significant 1.65-fold increase in the rate of SeMNPV-infected cells,a significant 0.54-fold increase in ODV production,a maximum 1.57-fold increase in BV production,and the larval survival dropped to 21%.Our findings show that SePGRP-LB has an antiviral function against SeMNPV,and therefore this gene may provide a target for lepidopteran pest control using virus insecticides.展开更多
Members of the peptidoglycan recognition protein （PGRP） family play essential roles in different manifestations of immune responses in insects. PGRP-LC, one of seven members of this family in the malaria vector Anop...Members of the peptidoglycan recognition protein （PGRP） family play essential roles in different manifestations of immune responses in insects. PGRP-LC, one of seven members of this family in the malaria vector Anopheles gambiae produced several spliced variants. Here we show that PGRP-LC, and not other members of the PGRP family nor the six members of the Gram-negative binding protein families, is required for the expression of antimicrobial peptide genes （such as CEC1 and GAM1） under the control of the Imd-Rel2 pathway in an A. gambiae cell line, 4a3A. PGRP-LC produces many splice variants that can be classified into three sub-groups （LC1, LC2 and LC3）, based on the carboxyl terminal sequences. RNA interference against one LC1 sub-group resulted in dramatic reduction of CEC1 and GAM1. Over-expression of LCla and to a lesser extent LC3a （a member of the LC1 and LC3 sub-group, respectively） in the 4a3A cell line enhances the expression of CEC1 and GAM1. These results demonstrate that the LC1-subgroup splice variants are essential for the expression of CEC1 and GAM1 in A. gambiae cell line.展开更多
Peptidoglycan recognition proteins （PGRP） play an important role in innate immunity in insects through the activation of the Imd pathway, which has been shown to be required in the antibacterial response in insects ...Peptidoglycan recognition proteins （PGRP） play an important role in innate immunity in insects through the activation of the Imd pathway, which has been shown to be required in the antibacterial response in insects and in the limitation of the number of Plasmodium berghei oocysts developing in mosquito midgut. The LCI gene of the PRGP family in Anopheles gambiae produces many products through alternative splicing. In this work, we demonstrate that PGRP-LC1a alone is sufficient to activate the Imd pathway in the A. gambiae L3-5 cell line through a combination of terminal or internal deletions, and RNA interference against endogenous PGRP-LC products. In the absence of endogenous PGRP-LC proteins, the integrity of the cytoplasmic domain is necessary for LCla function, while that of the extracellular domain is not. Moreover, the shorter the extracellular domain, the higher the activity for LC1 a. However, the removal of either the cytoplasmic or the extracellular PGRP-binding domain has little impact on the activity of LC 1 a in the presence of endogenous PGRP-LC proteins.展开更多
Protein protein recognition is an important step in biological processes, which still largely remains elusive. The inter residue contact potential, CP ij , describes the propensity of contact between two type...Protein protein recognition is an important step in biological processes, which still largely remains elusive. The inter residue contact potential, CP ij , describes the propensity of contact between two types of residue. In this study, several different CP ij variants were examined with the objective of discriminating the binding potential of surface pairs. Using solvent mediated inter molecule contact potential (SM IMCP ij ), an evaluation model was deduced and tested. Using the evaluation model it was found that the SM IMCP ij gives a better performance than either residue mediated IMCP ij (RM IMCP ij ) or folding residue contact potential (FCP ij ). The results suggest that the evaluation model provides a fast, effective, and discriminative method for the evaluation of proposed binding interfaces.展开更多
In this paper,a novel method to automatically detect protein spots on a two-dimensional(2-D)electrophoresis gel image is proposed to implement proteomics analysis of complex analyte.On the basis of the identifying spo...In this paper,a novel method to automatically detect protein spots on a two-dimensional(2-D)electrophoresis gel image is proposed to implement proteomics analysis of complex analyte.On the basis of the identifying spots results based on color variation and spot size features,morphological feature is introduced as a new criterion to distinguish protein spots from non-protein spots.Image-sharpening,edge-detecting and morphological feature extraction methods were consequently combined to detect protein spots on a 2-D electrophoresis gel image subject to strong disturbance.The proposed method was applied to detect the protein spots of proteomic gel images from E.coli cell,human kidney tissue and human serum.The results demonstrated that this method is more accurate and reliable than previous methods such as PDQuest 7.2 and ImageMaster 5.0 software for detecting protein spots on gel images with strong interferences.展开更多
基金Acknowledgments This work was supported by National Basic Research Program of China （No. 2014CB138405）, Strategic Priority Research Program of CAS （No. XDB 11030600）, National Natural Science Foundation of China （No. 31472008, 31401804, 31272497）, Open Research Fund Program of State Key Laboratory of Integrated Pest Management （Chinese IPM1407, 1304）.
文摘Peptidoglycan recognition proteins （PGRPs） are a family of innate immune receptors that specifically recognize peptidoglycans （PGNs） on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator （MmePGRPs）. To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown ofMmePGRP-S1. The knockdown of MmePGRP-S1 （iMmePGRP-S1） dramatically affected wasps＇ survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S 1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.
基金financially supported by the National Natural Science Foundation of China(Nos.22325701,U22A20332,92156025 and 92253301)the National Key Research and Development Program of China(Nos.2022YFA0912400 and 2021YFA0909900)the Beijing Natural Science Foundation(No.JQ20034).
文摘Protein recognition using host-vip recognition approach is of great interest but has been limited mainly to the protein N-terminal residues.Here,we site-specific incorporated two novel non-canonical amino acids containing supramolecular vip motifs into protein via an expanded genetic code.Through Staudinger reduction reactions,the encoded unnatural residues on protein becoming activated and can be specifically recognized by cucurbit[7]uril(CB[7])and cucurbit[8]uril(CB[8]).We demonstrated that enzyme containing vip amino acid incorporated near the active site can be reversibly regulated by CB[7]recognition,and CB[8]recognition induces protein dimerization.These amino acids will make useful addition to the supramolecular toolbox for protein targeting using molecular recognition approaches.
基金financial support from the National Natural Science Foundation of China(No.22275148)National Key R&D Program of China(No.2018YFB1900201)for Qiuyu Zhang+2 种基金the National Natural Science Foundation of China(No.22271232)Fundamental Research Funds for the Central Universities(No.D5000230114)for Shixin Fathe Fundamental Research Funds for the Central Universities(No.D5000220339)for Qing Liu。
文摘This work develops a protein imprinted nanosphere with varied recognition specificity for bovine serum albumin(BSA)and lysozyme(Lyz)under different UV light through a gradient dual crosslinked imprinting strategy(i.e.,covalent crosslinking and dynamic reversible crosslinking).The imprinting cavities are initially constructed using irreversible covalent crosslinking to specifically recognize BSA,and then the coumarin residues in the imprinting cavities are crosslinked under 365 nm UV light to further imprint Lyz,because Lyz has smaller size than BSA.Since the photo-crosslinking of coumarin is a reversible reaction,the imprinting cavities of Lyz can be de-crosslinked under 254 nm UV light and restore the imprinting cavities of BSA.Moreover,the N-isopropyl acrylamide(NIPAM)and pyrrolidine residues copolymerized in the polymeric surface of the nanospheres are temperature-and p H-responsive respectively.Therefore,the protein rebinding and release behaviors of the nanospheres are controlled by external temperature and p H.As a result,the materials can selectively separate BSA from real bovine whole blood and Lyz from egg white under different UV light.This study may provide a new strategy for construction of protein imprinted materials with tunable specificity for different proteins.
基金supported by the Project from the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (10KJB240001)the Foundation for Talent Recruitment of Yancheng Institute of Technology (XKR2011007)the National Natural Science Foundation of China (30830083)
文摘Peptidoglycan recognition proteins（PGRPs） are a family of pattern recognition receptors（PRRs） of the immune system,which bind and hydrolyze bacterial peptidoglycan.Here,a long type PGRP（PGRP-L） was first cloned in the lower vertebrate species Xenopus tropicalis（Xt）.The XtPGRP-L possessed a conserved genomic structure with five exons and four introns.The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP.The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb.During embryonic development,XtPGRP-L was not expressed until the 72 h tadpole stage.In adult tissues,it was strongly expressed in the liver,lung,intestine,and stomach.Furthermore,after LPS stimulation,the expression of XtPGRP-L was up-regulated significantly in the liver,intestine and spleen,indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.
基金the National Natural Science Foundation of China(Nos.21374058,21474060 and 21574078)the Ph.D. Programs Foundation of Ministry of Education of China(No 201331081100166)the Shanghai Rising-Star Program(No.16QA1401800)
文摘Thermoresponsive biotinylated dendronized copolymers carrying dendritic oligoethylene glycol（OEG）pendants were prepared via free radical polymerization,and their protein recognitions based on biotin-avidin interaction investigated.Both first（PG1） and second generation（PG2） dendronized copolymers were designed to examine possible thickness effects on the interaction between biotin and avidin.Inherited from the outstanding thermoresponsive properties from OEG dendrons,these biotinylated cylindrical copolymers show characteristic thermoresponsive behavior which provides an envelope to capture avidin through switching temperatures above or below their phase transition temperatures（T_（cp）s）.Thus,the recognition of polymer-supported biotin with avidin was investigated with UV/vis spectroscopy and dynamic laser light scattering.In contrast to the case for PG1,the increased thickness for copolymer PG2 hinders partially and inhibits the recognition of biotin moieties with avidin either below or above its T_（cp）.This demonstrates the significant architecture effects from dendronized polymers on the biotin moieties to shift onto periphery of the collapsed aggregates,which should be a prerequisite for protein recognition.These kinds of novel thermoresponsive copolymers may pave a way for the interesting biological applications in areas such as reversible activity control of enzyme or proteins,and for controlled delivery of drugs or genes.
基金supported by the National Key Research and Development Program of China(No.2018YFD0901405)the Zhejiang Major Program of Science and Technology(No.2016C02055-9)+1 种基金the Ningbo Major Project of Science and Technology(No.2019B10005)the China Agriculture Research System of MOF and MARA,National Marine Genetic Resource Center Program.
文摘Peptidoglycan recognition protein(PGRP)plays a vital role in invertebrate innate immunity system as a specific pattern recognition receptor for peptidoglycan.Bivalves possess various PGRP systems for self-defense;however,it has not been characterized in razor clam Sinonovacula constricta.In this study,eight PGRP coding sequences were identified and analyzed from S.constricta genome,which are designated as ScPGRP-S1,ScPGRP-S2,ScPGRP-S3,ScPGRP-S4,ScPGRP-S5,ScPGRP-S6,ScPGRP-S7,ScPGRP-S8.The results of molecular evolutionary analyses showed that all eight ScPGRP genes were highly conserved and exhi-bited a typical PGRP/amidase_2 domain as PGRP genes in other mollusks.Moreover,the presence of signal peptides was predicted in ScPGRP-S2,ScPGRP-S3 and ScPRP-S6,while a transmembrane structure only existed in ScPGRP-S6.Notably,a tertiary struc-ture analysis indicated that no disulfide bond was observed in ScPGRP-S5 and ScPGRP-S7.The mRNA transcripts analysis of ScPGRPs revealed that the high expression patterns of ScPGRP-S1 and ScPGRP-S4 were found in mantle,adductor muscle and foot,while those of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 were observed in hepatopancreas.Furthermore,the temporal expression profiles of ScPGRPs in the hepatopancreas were analyzed by qPCR<https://www.sciencedirect.com/topics/immunology-and-microbiology/real-time-polymerase-chain-reaction>after Gram-negative Vibrio parahaemolyticus and Gram-positive Staphylococcus aureus challenges.The mRNA expressions of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 could be induced by V.pa-rahaemolyticus and S.aureus.Overall,our findings indicated that ScPGRPs were involved in the immune defense against invaders,which constituted a comprehensive understanding of the potential role of PGRP genes in S.constricta.
基金supported by the National Natural Science Foundation of China (No.90813018)the Youth Foundation of Shanxi Province (No.2006021009)as well as the Youth Scientific and Technical Foundation of Shanxi University (Nos.2006007 and 2007112).
文摘The interaction of the novel tetra-carboxylphenyl calix[4]arene （TCPC） with the bovine heart cytochrome c （Cc） was first investigated by fluorescence spectroscopy and molecular modeling methods. The formation of a stable 1：1 complex was monitored by fluorescence titration, and its binding constant is 1.916 ×10^7 L mol^-1. Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface, that is, the electrostatic interaction drives TCPC to the Cc surface, and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.
文摘With the support by the National Natural Science Foundation of China,a study led by Prof.Lu Boxun(鲁伯埙)from Fudan University demonstrates that a toxic mutant HTT species is resistant to selective autophagy,revealing the fundamental mechanism of Huntington’s Disease.The study was published
基金funded by the National Key R&D Program of China (grant numbers 2021YFA0805800, 2023YFE0107700, and 2020YFA0803202 to R.J.)the 111 Project (grant number D18010 to R.J.)+3 种基金the National Natural Science Foundation of China (grant number 31970538 to R.J.)the Guangzhou Medical University Discipline Construction Funds (Basic Medicine) (grant number JCXKJS2022A02 to R.J.)the Medical Scientific Research Foundation of Guangdong Province (grant number A2019292 to J.L.)the Natural Science Foundation of Guangdong Province (grant number 2017A030310403 to Z.D.)
文摘Trained immunity is essential for innate immune cells to retain a memory of previously encountered pathogens,strengthening the hosts’response against these pathogens.However,the mechanisms governing trained immunity have not been well elucidated.In this study,flies of different genotypes were trained with heat-killed gram-negative(G)bacteria and subsequently reinfected with live pathogens.The innate immune responses against reinfection were evaluated through assessments of survival rates,antimicrobial peptide expression levels,and bacterial loads,complemented by transcriptomic and chromatin immunoprecipitation(ChIP)analyses.We found that flies trained with heat-killed gram-negative bacteria exhibited a higher survival rate upon secondary infection compared to unprimed flies,which was associated with increased expression of antimicrobial peptides.Priming with Gbacteria increased the sensitivity of the immune deficiency pathway to a second bacterial infection owing to lower levels of peptidoglycan recognition protein SC(PGRP-SC)after the first infection.The gut was the major tissue involved in the downregulation of PGRP-SC expression.The histone H3 lysine 9 trimethylation(H3K9me3)levels were higher at the PGRP-SC loci in immune-trained flies compared to untrained flies,contributing to the suppression of PGRP-SC expression.PGRP-SC overexpression in the fly gut abolished the effect of trained immunity.Taken together,our studies identify an innate immune memory in Drosophila that is regulated by gut-derived PGRP-SC through H3K9me3-mediated epigenetic repression of the PGRP-SC.
文摘The β-1,3-glucan recognition protein gene from Spodoptera exigua （SeβGRP） was cloned and characterized. The cDNA of this gene is 1？644 nucleotides in length and the predicted polypeptide is 491 amino acids （aa） in length, with a calculated molecular mass of 54.8 kDa. The first 22 aa encode a predicted secretion signal peptide. A BLAST search, multiple sequence alignment, and phylogenetic analysis of the aa sequence of SeβGRP revealed that this protein is most similar to the β-1,3-glucan recognition protein （βGRP） family of pattern recognition proteins. Using reverse-transcription polymerase chain reaction, we detected the presence of SeβGRP transcripts in the egg, larval, pupal, and adult stages of S. exigua. In addition, the SeβGRP transcript was expressed in all the tissues examined including the brain, hemocytes, fat body, intestine, and cuticle. There were no changes in SeβGRP mRNA levels in larvae infected with ultraviolet （UV）-killed Escherichia coli DH5α compared with the control larvae inoculated with the water; however, SeβGRP mRNA levels were markedly elevated 4–8 h after infection and slightly induced 12–24 h after infection in larvae injected with UV-killed Fusarium oxysporum. This may be because β-1,3-glucan is the main component of the cell wall of F. oxysporum, but not E. coli DH5α.
基金funded by National Natural Science Foundation of China(31972333)Shandong Provincial Natural Science Foundation(ZR2020MC128,ZR2020MC130)Basic Research Project of Shenzhen Municipal Science and Technology Innovation Committee(JCYJ20190813144407666).
文摘Peptidoglycan recognition proteins(PGRPs)are a class of molecules that play a critical role in insect immunity.Understanding the function of PGRPs is important to improve the efficiency of microbial insecticides.In this study,we investigated the role of PGRP-LB(a long type PGRP)in insect immunity against viruses using Spodoptera exigua and Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV)as an insect-virus model.We cloned and identified a PGRP-LB gene from S.exigua;the gene consisted of 7 exons that encoded a polypeptide of 234 amino acids with a signal peptide and a typical amidase domain.Expression analysis revealed that the abundance of SePGRP-LB transcripts in the fat body was greater than in other tissues.Overexpression of SePGRP-LB resulted in a significant decrease of 49%in the rate of SeMNPV-infected cells.In addition,the multiplication of SeMNPV was significantly decreased:a decrease of 79%in the production of occlusion-derived virion(ODV),and a maximum decrease of 50%in the production of budded virion(BV).In contrast,silencing of SePGRP-LB expression by RNA interference resulted in a significant 1.65-fold increase in the rate of SeMNPV-infected cells,a significant 0.54-fold increase in ODV production,a maximum 1.57-fold increase in BV production,and the larval survival dropped to 21%.Our findings show that SePGRP-LB has an antiviral function against SeMNPV,and therefore this gene may provide a target for lepidopteran pest control using virus insecticides.
文摘Members of the peptidoglycan recognition protein （PGRP） family play essential roles in different manifestations of immune responses in insects. PGRP-LC, one of seven members of this family in the malaria vector Anopheles gambiae produced several spliced variants. Here we show that PGRP-LC, and not other members of the PGRP family nor the six members of the Gram-negative binding protein families, is required for the expression of antimicrobial peptide genes （such as CEC1 and GAM1） under the control of the Imd-Rel2 pathway in an A. gambiae cell line, 4a3A. PGRP-LC produces many splice variants that can be classified into three sub-groups （LC1, LC2 and LC3）, based on the carboxyl terminal sequences. RNA interference against one LC1 sub-group resulted in dramatic reduction of CEC1 and GAM1. Over-expression of LCla and to a lesser extent LC3a （a member of the LC1 and LC3 sub-group, respectively） in the 4a3A cell line enhances the expression of CEC1 and GAM1. These results demonstrate that the LC1-subgroup splice variants are essential for the expression of CEC1 and GAM1 in A. gambiae cell line.
文摘Peptidoglycan recognition proteins （PGRP） play an important role in innate immunity in insects through the activation of the Imd pathway, which has been shown to be required in the antibacterial response in insects and in the limitation of the number of Plasmodium berghei oocysts developing in mosquito midgut. The LCI gene of the PRGP family in Anopheles gambiae produces many products through alternative splicing. In this work, we demonstrate that PGRP-LC1a alone is sufficient to activate the Imd pathway in the A. gambiae L3-5 cell line through a combination of terminal or internal deletions, and RNA interference against endogenous PGRP-LC products. In the absence of endogenous PGRP-LC proteins, the integrity of the cytoplasmic domain is necessary for LCla function, while that of the extracellular domain is not. Moreover, the shorter the extracellular domain, the higher the activity for LC1 a. However, the removal of either the cytoplasmic or the extracellular PGRP-binding domain has little impact on the activity of LC 1 a in the presence of endogenous PGRP-LC proteins.
基金Supported by the National Natural Science Foundation (No.39970 15 5 ) the High- Technology Developm entProgram of China (No.2 0 0 1AA 2 330 11) +1 种基金and theNational Frontier Research Program (No.G19990 75 6 0 2 G19990 1190 2 and19980 5 110 5 )
文摘Protein protein recognition is an important step in biological processes, which still largely remains elusive. The inter residue contact potential, CP ij , describes the propensity of contact between two types of residue. In this study, several different CP ij variants were examined with the objective of discriminating the binding potential of surface pairs. Using solvent mediated inter molecule contact potential (SM IMCP ij ), an evaluation model was deduced and tested. Using the evaluation model it was found that the SM IMCP ij gives a better performance than either residue mediated IMCP ij (RM IMCP ij ) or folding residue contact potential (FCP ij ). The results suggest that the evaluation model provides a fast, effective, and discriminative method for the evaluation of proposed binding interfaces.
基金the National Natural Science Foundat ion of China(Grant No.90209005)Science and Technology Project of Zhejiang Province(Grant No.2004C33026).
文摘In this paper,a novel method to automatically detect protein spots on a two-dimensional(2-D)electrophoresis gel image is proposed to implement proteomics analysis of complex analyte.On the basis of the identifying spots results based on color variation and spot size features,morphological feature is introduced as a new criterion to distinguish protein spots from non-protein spots.Image-sharpening,edge-detecting and morphological feature extraction methods were consequently combined to detect protein spots on a 2-D electrophoresis gel image subject to strong disturbance.The proposed method was applied to detect the protein spots of proteomic gel images from E.coli cell,human kidney tissue and human serum.The results demonstrated that this method is more accurate and reliable than previous methods such as PDQuest 7.2 and ImageMaster 5.0 software for detecting protein spots on gel images with strong interferences.
