Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translatio...Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translational modifications is one of the key elements that allow the nervous system to adapt to environment stimulations. S-palmitoylation, an important lipid modification by post-translational addition of a long-chain fatty acid to a cysteine residue, regulates AMPA receptor trafficking, which dynamically affects multiple fundamental brain functions, such as learning and memory. In vivo, S-palmitoylation is controlled by palmitoyl acyl transferases and palmitoyl thioesterases.In this review, we highlight advances in the mechanisms for dynamic AMPA receptors palmitoylation,and discuss how palmitoylation affects AMPA receptors function at synapses in recent years.Pharmacological regulation of S-palmitoylation may serve as a novel therapeutic strategy for neurobiological diseases.展开更多
Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversib...Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversible;a feature of protein palmitoylation that allows for rapid regulation of the function of many cellular proteins.Mutations in palmitoyltransferases(PATs),the enzymes that catalyze the formation of this modification,are associated with a number of neurological diseases and cancer progression.This review summarizes the crucial role of palmitoylation in biological systems,the discovery of the DHHC protein family that catalyzes protein palmitoylation,and the development of methods for investigating the catalytic mechanism of PATs.展开更多
Soybean mosaic virus (SMV) causes severe yield losses and seed quality reduction in soybean (Glycine max) production worldwide. Rsc4 from cultivar Dabaima is a dominant genetic locus for SMV resistance, and its mappin...Soybean mosaic virus (SMV) causes severe yield losses and seed quality reduction in soybean (Glycine max) production worldwide. Rsc4 from cultivar Dabaima is a dominant genetic locus for SMV resistance, and its mapping interval contains three Nucleotide-binding domain Leucine-rich Repeat containing (NLR) candidates (Rsc4-1, Rsc4-2, and Rsc4-3). The NLR-type resistant proteins were considered as important intracellular pathogen sensors in the previous studies. In this research, based on transient expression assay in Nicotiana benthamiana leaves, we found that the longest transcript of Rsc4-3 is sufficient to induce resistance response to SMV;and CRISPR/Cas9-mediated Rsc4-3 knockout in resistant cultivar Dabaima compromised the resistance. These indicate that Rsc4-3 confers resistance to SMV. Interestingly, Rsc4-3 encodes a cell wall localized NLR-type resistant protein (Rsc4-3). The internal polypeptide region responsible for apoplastic targeting of Rsc4-3 and the putative palmitoylation sites on the N-terminus are essential for the resistance response. Furthermore, we showed that viral-encoded cylindrical inclusion (CI) protein partially localizes to the cell wall and can interact with Rsc4-3. Virus-driven or transient expression of CI protein of avirulent SMV strains is enough to induce resistance response in the presence of Rsc4-3, suggesting that CI is the avirulent gene for Rsc4-3 mediated resistance. Our work exhibited a case of NLR recognizing virus in the apoplast and provided a simple and effective method for identifying resistant genes against SMV infection.展开更多
The majority of colorectal cancer patients are not responsive to immune checkpoint blockade(ICB).The interferon gamma(IFNγ)signaling pathway drives spontaneous and ICB-induced antitumor immunity.In this review,we sum...The majority of colorectal cancer patients are not responsive to immune checkpoint blockade(ICB).The interferon gamma(IFNγ)signaling pathway drives spontaneous and ICB-induced antitumor immunity.In this review,we summarize recent advances in the epigenetic,genetic,and functional integrity of the IFNγsignaling pathway in the colorectal cancer microenvironment and its immunological relevance in the therapeutic efficacy of and resistance to ICB.Moreover,we discuss how to target IFNγsignaling to inform novel clinical trials to treat patients with colorectal cancer.展开更多
Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the ...Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the TCA cycle,is palmitoylated at cysteine 138(C138) residue,resulting in increased activity of MDH2.We next identify that ZDHHC18 acts as a palmitoyltransferase of MDH2.Glutamine deprivation enhances MDH2 palmitoylation by increasing the binding between ZDHHC18 and MDH2.MDH2 silencing represses mitochondrial respiration as well as ovarian cancer cell proliferation both in vitro and in vivo.Intriguingly,re-expression of wild-type MDH2,but not its palmitoylation-deficient C138 S mutant,sustains mitochondrial respiration and restores the growth as well as clonogenic capability of ovarian cancer cells.Notably,MDH2 palmitoylation level is elevated in clinical cancer samples from patients with high-grade serous ovarian cancer.These observations suggest that MDH2 palmitoylation catalyzed by ZDHHC18 sustains mitochondrial respiration and promotes the malignancy of ovarian cancer,yielding possibilities of targeting ZDHHC18-mediated MDH2 palmitoylation in the treatment of EOC.展开更多
Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of t...Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of the STING signaling pathway is associated with autoinflammatory diseases,including systemic lupus erythematosus and Aicardi–Goutières syndrome(AGS).Two independent studies recently identified pharmacological inhibitors of STING.Strikingly,both types of compounds are reactive nitrocontaining electrophiles that target STING palmitoylation,a posttranslational modification necessary for STING signaling.As a consequence,the activation of downstream signaling molecules and the induction of type I interferons were inhibited.The compounds were effective at ameliorating inflammation in a mouse model of AGS and in blocking the production of type I interferons in primary fibroblasts from SAVI patients.This mini-review focuses on the roles of palmitoylation in STING activation and signaling and as a pharmaceutical target for drug development.展开更多
Alterations in cellular calcium(Ca^(2+))signals have been causally associated with the development and progression of human cancers.Cellular Ca^(2+)signals are generated by channels,pumps,and exchangers that move Ca^(...Alterations in cellular calcium(Ca^(2+))signals have been causally associated with the development and progression of human cancers.Cellular Ca^(2+)signals are generated by channels,pumps,and exchangers that move Ca^(2+)ions across membranes and are decoded by effector proteins in the cytosol or in organelles.S-acylation,the reversible addition of 16-carbon fatty acids to proteins,modulates the activity of Ca^(2+)transporters by altering their affinity for lipids,and enzymes mediating this reversible post-translational modification have also been linked to several types of cancers.Here,we compile studies reporting an association between Ca^(2+)transporters or S-acylation enzymes with specific cancers,as well as studies reporting or predicting the S-acylation of Ca^(2+)transporters.We then discuss the potential role of S-acylation in the oncogenic potential of a subset of Ca^(2+)transport proteins involved in cancer.展开更多
AIMTo investigate the role of non-structural open reading frame 1 “Y-domain” sequences in the hepatitis E virus (HEV) life cycle.METHODSSequences of human HEV Y-domain (amino acid sequences 216...AIMTo investigate the role of non-structural open reading frame 1 “Y-domain” sequences in the hepatitis E virus (HEV) life cycle.METHODSSequences of human HEV Y-domain (amino acid sequences 216-442) and closely-related viruses were analyzed in silico. Site-directed mutagenesis of the Y-domain (HEV SAR55) was carried out and studied in the replicon-baculovirus-hepatoma cell model. In vitro transcribed mRNA (pSK-GFP) constructs were transfected into S10-3 cells and viral RNA replicating GFP-positive cells were scored by flow cytometry. Mutant virions’ infectivity was assayed on naïve HepG2/C3A cells.RESULTSIn silico analysis identified a potential palmitoylation-site (C<sub>336</sub>C<sub>337</sub>) and an α-helix segment (L<sub>410</sub>Y<sub>411</sub>S<sub>412</sub>W<sub>413</sub>L<sub>414</sub>F<sub>415</sub>E<sub>416</sub>) in the HEV Y-domain. Molecular characterization of C<sub>336</sub>A, C<sub>337</sub>A and W<sub>413</sub>A mutants of the three universally conserved residues showed non-viability. Further, of the 10 consecutive saturation mutants covering the entire Y-domain nucleotide sequences (nts 650-1339), three constructs (nts 788-994) severely affected virus replication. This revealed the indispensability of the internal sequences but not of the up- or downstream sequences at the transcriptional level. Interestingly, the three mutated residues corresponded to the downstream codons that tolerated saturation mutation, indicating their post-translational functional/structural essentiality. In addition, RNA secondary structure prediction revealed formation of stable hairpins (nts 788-994) where saturation mutation drastically inhibited virion infectivity.CONCLUSIONThis is the first demonstration of the critical role of Y-domain sequences in HEV life cycle, which may involve gene regulation and/or membrane binding in intracellular replication complexes.展开更多
The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be larg...The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.展开更多
基金supported by grants from the National Basic Research Program of China (the 973 Program, No. 2013CB531303 to Dr. Jianguo Chen No. 2014CB744601 to Fang Wang)+3 种基金the National Natural Scientific Foundation of China (NSFC, No. 81222048 to Fang Wang No. 81302754 to Peng Fei Wu)supported by the International Science & Technology Cooperation Program of China (No. 2011DFA32670 to Jianguo Chen)PCSIRT (No. IRT13016)
文摘Glutamate acting on AMPA-type ionotropic glutamate receptor(AMPAR) mediates the majority of fast excitatory synaptic transmission in the mammalian central nervous system. Dynamic regulation of AMPAR by post-translational modifications is one of the key elements that allow the nervous system to adapt to environment stimulations. S-palmitoylation, an important lipid modification by post-translational addition of a long-chain fatty acid to a cysteine residue, regulates AMPA receptor trafficking, which dynamically affects multiple fundamental brain functions, such as learning and memory. In vivo, S-palmitoylation is controlled by palmitoyl acyl transferases and palmitoyl thioesterases.In this review, we highlight advances in the mechanisms for dynamic AMPA receptors palmitoylation,and discuss how palmitoylation affects AMPA receptors function at synapses in recent years.Pharmacological regulation of S-palmitoylation may serve as a novel therapeutic strategy for neurobiological diseases.
基金financially supported by the NIH R01 grant GM040602 (CAF)
文摘Protein palmitoylation is a widespread lipid modification in which one or more cysteine thiols on a substrate protein are modified to form a thioester with a palmitoyl group.This lipid modification is readily reversible;a feature of protein palmitoylation that allows for rapid regulation of the function of many cellular proteins.Mutations in palmitoyltransferases(PATs),the enzymes that catalyze the formation of this modification,are associated with a number of neurological diseases and cancer progression.This review summarizes the crucial role of palmitoylation in biological systems,the discovery of the DHHC protein family that catalyzes protein palmitoylation,and the development of methods for investigating the catalytic mechanism of PATs.
基金This work was supported by the National Natural Science Foundation of China(31571690,31770164)the Fundamental Research Funds for the Central Universities(KYT201801)+3 种基金Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT_17R55)the National Soybean Industrial Technology System of China(CARS-004)Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP),the National Key R&D Program of China(2017YFD0101501)the Natural Science Foundation of Jiangsu Province(BK20180039).
文摘Soybean mosaic virus (SMV) causes severe yield losses and seed quality reduction in soybean (Glycine max) production worldwide. Rsc4 from cultivar Dabaima is a dominant genetic locus for SMV resistance, and its mapping interval contains three Nucleotide-binding domain Leucine-rich Repeat containing (NLR) candidates (Rsc4-1, Rsc4-2, and Rsc4-3). The NLR-type resistant proteins were considered as important intracellular pathogen sensors in the previous studies. In this research, based on transient expression assay in Nicotiana benthamiana leaves, we found that the longest transcript of Rsc4-3 is sufficient to induce resistance response to SMV;and CRISPR/Cas9-mediated Rsc4-3 knockout in resistant cultivar Dabaima compromised the resistance. These indicate that Rsc4-3 confers resistance to SMV. Interestingly, Rsc4-3 encodes a cell wall localized NLR-type resistant protein (Rsc4-3). The internal polypeptide region responsible for apoplastic targeting of Rsc4-3 and the putative palmitoylation sites on the N-terminus are essential for the resistance response. Furthermore, we showed that viral-encoded cylindrical inclusion (CI) protein partially localizes to the cell wall and can interact with Rsc4-3. Virus-driven or transient expression of CI protein of avirulent SMV strains is enough to induce resistance response in the presence of Rsc4-3, suggesting that CI is the avirulent gene for Rsc4-3 mediated resistance. Our work exhibited a case of NLR recognizing virus in the apoplast and provided a simple and effective method for identifying resistant genes against SMV infection.
基金This work was supported in part by U.S.NIH/NCI R01 grants(CA217648,CA123088,CA099985,CA193136,CA152470)the NIH through the University of Michigan Rogel Cancer Center Grant(CA46592).
文摘The majority of colorectal cancer patients are not responsive to immune checkpoint blockade(ICB).The interferon gamma(IFNγ)signaling pathway drives spontaneous and ICB-induced antitumor immunity.In this review,we summarize recent advances in the epigenetic,genetic,and functional integrity of the IFNγsignaling pathway in the colorectal cancer microenvironment and its immunological relevance in the therapeutic efficacy of and resistance to ICB.Moreover,we discuss how to target IFNγsignaling to inform novel clinical trials to treat patients with colorectal cancer.
基金supported by the National Key Research and Development Program of China (2020YFA0803402 and2019YFA0801703)the National Natural Science Foundation of China(81872240,81802745,81790250/81790253 and 91959202)Innovation Program of Shanghai Municipal Education Commission (N173606)。
文摘Epithelial ovarian cancer(EOC) exhibits strong dependency on the tricarboxylic acid(TCA) cycle and oxidative phosphorylation to fuel anabolic process.Here,we show that malate dehydrogenase 2(MDH2),a key enzyme of the TCA cycle,is palmitoylated at cysteine 138(C138) residue,resulting in increased activity of MDH2.We next identify that ZDHHC18 acts as a palmitoyltransferase of MDH2.Glutamine deprivation enhances MDH2 palmitoylation by increasing the binding between ZDHHC18 and MDH2.MDH2 silencing represses mitochondrial respiration as well as ovarian cancer cell proliferation both in vitro and in vivo.Intriguingly,re-expression of wild-type MDH2,but not its palmitoylation-deficient C138 S mutant,sustains mitochondrial respiration and restores the growth as well as clonogenic capability of ovarian cancer cells.Notably,MDH2 palmitoylation level is elevated in clinical cancer samples from patients with high-grade serous ovarian cancer.These observations suggest that MDH2 palmitoylation catalyzed by ZDHHC18 sustains mitochondrial respiration and promotes the malignancy of ovarian cancer,yielding possibilities of targeting ZDHHC18-mediated MDH2 palmitoylation in the treatment of EOC.
文摘Gain-of-function mutations in the STING-encoding gene TMEM173 are central to the pathology of the autoinflammatory disorder STING-associated vasculopathy with onset in infancy(SAVI).Furthermore,excessive activity of the STING signaling pathway is associated with autoinflammatory diseases,including systemic lupus erythematosus and Aicardi–Goutières syndrome(AGS).Two independent studies recently identified pharmacological inhibitors of STING.Strikingly,both types of compounds are reactive nitrocontaining electrophiles that target STING palmitoylation,a posttranslational modification necessary for STING signaling.As a consequence,the activation of downstream signaling molecules and the induction of type I interferons were inhibited.The compounds were effective at ameliorating inflammation in a mouse model of AGS and in blocking the production of type I interferons in primary fibroblasts from SAVI patients.This mini-review focuses on the roles of palmitoylation in STING activation and signaling and as a pharmaceutical target for drug development.
基金Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung(Grant/Award Number:310030_189042)。
文摘Alterations in cellular calcium(Ca^(2+))signals have been causally associated with the development and progression of human cancers.Cellular Ca^(2+)signals are generated by channels,pumps,and exchangers that move Ca^(2+)ions across membranes and are decoded by effector proteins in the cytosol or in organelles.S-acylation,the reversible addition of 16-carbon fatty acids to proteins,modulates the activity of Ca^(2+)transporters by altering their affinity for lipids,and enzymes mediating this reversible post-translational modification have also been linked to several types of cancers.Here,we compile studies reporting an association between Ca^(2+)transporters or S-acylation enzymes with specific cancers,as well as studies reporting or predicting the S-acylation of Ca^(2+)transporters.We then discuss the potential role of S-acylation in the oncogenic potential of a subset of Ca^(2+)transport proteins involved in cancer.
基金Supported by the Deanship of Scientific Research at King Saud University,Riyadh,No.RG-1435-053
文摘AIMTo investigate the role of non-structural open reading frame 1 “Y-domain” sequences in the hepatitis E virus (HEV) life cycle.METHODSSequences of human HEV Y-domain (amino acid sequences 216-442) and closely-related viruses were analyzed in silico. Site-directed mutagenesis of the Y-domain (HEV SAR55) was carried out and studied in the replicon-baculovirus-hepatoma cell model. In vitro transcribed mRNA (pSK-GFP) constructs were transfected into S10-3 cells and viral RNA replicating GFP-positive cells were scored by flow cytometry. Mutant virions’ infectivity was assayed on naïve HepG2/C3A cells.RESULTSIn silico analysis identified a potential palmitoylation-site (C<sub>336</sub>C<sub>337</sub>) and an α-helix segment (L<sub>410</sub>Y<sub>411</sub>S<sub>412</sub>W<sub>413</sub>L<sub>414</sub>F<sub>415</sub>E<sub>416</sub>) in the HEV Y-domain. Molecular characterization of C<sub>336</sub>A, C<sub>337</sub>A and W<sub>413</sub>A mutants of the three universally conserved residues showed non-viability. Further, of the 10 consecutive saturation mutants covering the entire Y-domain nucleotide sequences (nts 650-1339), three constructs (nts 788-994) severely affected virus replication. This revealed the indispensability of the internal sequences but not of the up- or downstream sequences at the transcriptional level. Interestingly, the three mutated residues corresponded to the downstream codons that tolerated saturation mutation, indicating their post-translational functional/structural essentiality. In addition, RNA secondary structure prediction revealed formation of stable hairpins (nts 788-994) where saturation mutation drastically inhibited virion infectivity.CONCLUSIONThis is the first demonstration of the critical role of Y-domain sequences in HEV life cycle, which may involve gene regulation and/or membrane binding in intracellular replication complexes.
文摘The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.
