The high content of cyanogenic glycosides(CG)in cassava tubers affects food safety.CG are involved in the plant growth and development and protect cassava leaves from herbivorous predators.However,the regulatory mecha...The high content of cyanogenic glycosides(CG)in cassava tubers affects food safety.CG are involved in the plant growth and development and protect cassava leaves from herbivorous predators.However,the regulatory mechanism of CG biosynthesis remains poorly understood.Here,yeast one-hybrid assays were performed using a mixed cDNA library of cassava tubers and leaves as prey and the promoter of MeCYP79D2 as bait.MeCYP79D2,a cytochrome P450 protein,is the rate-limiting enzyme for CG synthesis in cassava.From this information,a candidate regulator of MeCYP79D2 was selected and identified as transcription factor MePHD1.2.MePHD1.2,located in the nucleus and exhibiting an inhibitory transcription activity directly bound to an AT-rich motif in the promoter of MeCYP79D2.In cassava,the transcriptional activity of MeCYP79D2 was considerably enhanced in mephd1.2 mutant lines leading to increased linamarin and lotaustralin contents.Deletion of MePHD1.2 promoted the production of CGs in cassava and decreased transcription inhibition on MeCYP79D2,exposing a novel regulatory module governing biosynthesis of CGs.展开更多
Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrha...Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.展开更多
Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins ...Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.展开更多
Allergic inflammation is closely related to the activation of mast cells(MCs),which is regulated by its intracellular Ca^(2+) plevel,but the intake and effects of the intracellular Ca^(2+) premain unclear.The Ca^(2+) ...Allergic inflammation is closely related to the activation of mast cells(MCs),which is regulated by its intracellular Ca^(2+) plevel,but the intake and effects of the intracellular Ca^(2+) premain unclear.The Ca^(2+) pinflux is controlled by members of Ca^(2+) pchannels,among which calcium voltage-gated channel subunit alpha1 C(CaV1.2)is the most robust.This study aimed to reveal the role and underlying mechanism of MC CaV1.2 in allergic inflammation.We found that CaV1.2 participated in MC activation and allergic inflammation.Nimodipine(Nim),as a strong CaV1.2-specific antagonist,ameliorated allergic inflammation in mice.Further,CaV1.2 activation in MC was triggered by phosphatizing at its Ser1928 through protein kinase C(PKC),which calcium/calmodulin-dependent protein kinase II(CaMKII)catalyzed.Overexpression or knockdown of MC CaV1.2 influenced MC activation.Importantly,CaV1.2 expression in MC had detrimental effects,while its deficiency ameliorated allergic pulmonary inflammation.Results provide novel insights into CaV1.2 function and a potential drug target for controlling allergic inflammation.展开更多
基金supported by grants from the National Natural Science Foundation of China(32460505)China Agriculture Research System(CARS-11)+2 种基金the Chinese Academy of Tropical Agricultural Sciences for the Science and Technology Innovation Team of the National Tropical Agricultural Science Center(CATASCXTD202301)Additional support was provided by the Hainan Province Graduate Innovation Research Project(Hyb2020-09)the Key Laboratory of Tropical Fruits and Vegetables Quality and Safety for State Market Regulation(KF-2023016).
文摘The high content of cyanogenic glycosides(CG)in cassava tubers affects food safety.CG are involved in the plant growth and development and protect cassava leaves from herbivorous predators.However,the regulatory mechanism of CG biosynthesis remains poorly understood.Here,yeast one-hybrid assays were performed using a mixed cDNA library of cassava tubers and leaves as prey and the promoter of MeCYP79D2 as bait.MeCYP79D2,a cytochrome P450 protein,is the rate-limiting enzyme for CG synthesis in cassava.From this information,a candidate regulator of MeCYP79D2 was selected and identified as transcription factor MePHD1.2.MePHD1.2,located in the nucleus and exhibiting an inhibitory transcription activity directly bound to an AT-rich motif in the promoter of MeCYP79D2.In cassava,the transcriptional activity of MeCYP79D2 was considerably enhanced in mephd1.2 mutant lines leading to increased linamarin and lotaustralin contents.Deletion of MePHD1.2 promoted the production of CGs in cassava and decreased transcription inhibition on MeCYP79D2,exposing a novel regulatory module governing biosynthesis of CGs.
基金supported by the National Natural Science Foundation of China,Nos.U2004106 (to WY),81971061 (to JC)the Key Scientific Research Project of Colleges and Universities in Henan Province,No.21A320039 (to WY)。
文摘Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.
基金Supported by the National Natural Science Foundation of China(No.31970429)the Shandong Provincial Natural Science Foundation(No.ZR 2022 MC 032)。
文摘Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.
基金funded by National Natural Science Foundation of China(Grant Nos.:81930096 and 82274063).
文摘Allergic inflammation is closely related to the activation of mast cells(MCs),which is regulated by its intracellular Ca^(2+) plevel,but the intake and effects of the intracellular Ca^(2+) premain unclear.The Ca^(2+) pinflux is controlled by members of Ca^(2+) pchannels,among which calcium voltage-gated channel subunit alpha1 C(CaV1.2)is the most robust.This study aimed to reveal the role and underlying mechanism of MC CaV1.2 in allergic inflammation.We found that CaV1.2 participated in MC activation and allergic inflammation.Nimodipine(Nim),as a strong CaV1.2-specific antagonist,ameliorated allergic inflammation in mice.Further,CaV1.2 activation in MC was triggered by phosphatizing at its Ser1928 through protein kinase C(PKC),which calcium/calmodulin-dependent protein kinase II(CaMKII)catalyzed.Overexpression or knockdown of MC CaV1.2 influenced MC activation.Importantly,CaV1.2 expression in MC had detrimental effects,while its deficiency ameliorated allergic pulmonary inflammation.Results provide novel insights into CaV1.2 function and a potential drug target for controlling allergic inflammation.
