从韩国浦项科技大学(Pohang University of Science and Technology,POSTECH)水稻T-DNA插入突变体库PFG_3A-04871.R株系中筛选到一个NADK3(NAD Kinase 3)激酶(LOC_Os05g32210)基因OSNADK3表达缺失的突变杂合体。与其野生型Dongjing(Oryz...从韩国浦项科技大学(Pohang University of Science and Technology,POSTECH)水稻T-DNA插入突变体库PFG_3A-04871.R株系中筛选到一个NADK3(NAD Kinase 3)激酶(LOC_Os05g32210)基因OSNADK3表达缺失的突变杂合体。与其野生型Dongjing(Oryza sativa L.var.japonica cv Dongjing)比较,该OSNADK3基因突变杂合体表现出明显的植株矮小、花发育异常以及不育等特点。为明确水稻NADK3激酶的功能,我们利用RT-PCR的方法克隆了水稻(Dongjing)OSNADK3基因的编码区(CDS),将OSNADK3导入表达载体pCAMBIA1301::35S::GFP(pCG)中,构建了OSNADK3和绿色荧光蛋白(GFP)融合表达载体pCAMBIA1301::35S::NADK3::GFP(pCNG),该融合表达载体能够在拟南芥叶中表达,亚细胞组织定位分析表明,OSNADK3在拟南芥细胞质中表达,表明该酶是细胞质定位的酶类。然后,利用农杆菌介导的方法侵染水稻愈伤组织,获得了24株独立的转基因水稻植株。经PCR初步鉴定,目的片段OSNADK3已经成功整合到水稻基因组中,为进一步深入研究水稻OSNADK3的功能与作用机制奠定了基础。展开更多
Nicotinamide adenine dinucleotide(NAD^(+))kinase(NADK)phosphorylates NAD^(+)to generate NADP^(+),which plays a crucial role in maintaining NAD^(+)/NADp^(+)homeostasis,cellular redox balance,and metabolism.However,how ...Nicotinamide adenine dinucleotide(NAD^(+))kinase(NADK)phosphorylates NAD^(+)to generate NADP^(+),which plays a crucial role in maintaining NAD^(+)/NADp^(+)homeostasis,cellular redox balance,and metabolism.However,how human NADK activity is regulated,and how dysregulation or mutation of NADK is linked to human diseases,such as cancers,are still not fully understood.Here,we present a cryo-EM structure of human tetrameric NADK and elaborate on the necessity of the NADK tetramer for its activity.The N-terminal region of human NADK,which does not exist in bacterial NADKs,modulates tetramer conformation,thereby regulating its activity.A methylation-deficient mutant,R45H,within the N-terminal region results in increased NADK activity and confers cancer chemotherapy resistance.Conversely,mutations in NADK identified among cancer patients alter the tetramer conformation,resulting in NADK inactivation and increasing the sensitivity of lung cancer cells to chemotherapy.Our findings partially unveil the structural basis for NADK regulation,offering insights into the cancer etiology of patients carrying NADK mutations.展开更多
Nicotinamide adenine dinucleotide(NAD^(+))/reduced NAD^(+)(NADH)and nicotinamide adenine dinucleotide phosphate(NADP^(+))/reduced NADP^(+)(NADPH)are essential metabolites involved in multiple metabolic pathways and ce...Nicotinamide adenine dinucleotide(NAD^(+))/reduced NAD^(+)(NADH)and nicotinamide adenine dinucleotide phosphate(NADP^(+))/reduced NADP^(+)(NADPH)are essential metabolites involved in multiple metabolic pathways and cellular processes.NAD^(+)and NADH redox couple plays a vital role in catabolic redox reactions,while NADPH is crucial for cellular anabolism and antioxidant responses.Maintaining NAD(H)and NADP(H)homeostasis is crucial for normal physiological activity and is tightly regulated through various mechanisms,such as biosynthesis,consumption,recycling,and conversion between NAD(H)and NADP(H).The conversions between NAD(H)and NADP(H)are controlled by NAD kinases(NADKs)and NADP(H)phosphatases[specifically,metazoan SpoT homolog-1(MESH1)and nocturnin(NOCT)].NADKs facilitate the synthesis of NADP^(+)from NAD^(+),while MESH1 and NOCT convert NADP(H)into NAD(H).In this review,we summarize the physiological roles of NAD(H)and NADP(H)and discuss the regulatory mechanisms governing NAD(H)and NADP(H)homeostasis in three key aspects:the transcriptional and posttranslational regulation of NADKs,the role of MESH1 and NOCT in maintaining NAD(H)and NADP(H)homeostasis,and the influence of the circadian clock on NAD(H)and NADP(H)homeostasis.In conclusion,NADKs,MESH1,and NOCT are integral to various cellular processes,regulating NAD(H)and NADP(H)homeostasis.Dysregulation of these enzymes results in various human diseases,such as cancers and metabolic disorders.Hence,strategies aiming to restore NAD(H)and NADP(H)homeostasis hold promise as novel therapeutic approaches for these diseases.展开更多
文摘从韩国浦项科技大学(Pohang University of Science and Technology,POSTECH)水稻T-DNA插入突变体库PFG_3A-04871.R株系中筛选到一个NADK3(NAD Kinase 3)激酶(LOC_Os05g32210)基因OSNADK3表达缺失的突变杂合体。与其野生型Dongjing(Oryza sativa L.var.japonica cv Dongjing)比较,该OSNADK3基因突变杂合体表现出明显的植株矮小、花发育异常以及不育等特点。为明确水稻NADK3激酶的功能,我们利用RT-PCR的方法克隆了水稻(Dongjing)OSNADK3基因的编码区(CDS),将OSNADK3导入表达载体pCAMBIA1301::35S::GFP(pCG)中,构建了OSNADK3和绿色荧光蛋白(GFP)融合表达载体pCAMBIA1301::35S::NADK3::GFP(pCNG),该融合表达载体能够在拟南芥叶中表达,亚细胞组织定位分析表明,OSNADK3在拟南芥细胞质中表达,表明该酶是细胞质定位的酶类。然后,利用农杆菌介导的方法侵染水稻愈伤组织,获得了24株独立的转基因水稻植株。经PCR初步鉴定,目的片段OSNADK3已经成功整合到水稻基因组中,为进一步深入研究水稻OSNADK3的功能与作用机制奠定了基础。
文摘Nicotinamide adenine dinucleotide(NAD^(+))kinase(NADK)phosphorylates NAD^(+)to generate NADP^(+),which plays a crucial role in maintaining NAD^(+)/NADp^(+)homeostasis,cellular redox balance,and metabolism.However,how human NADK activity is regulated,and how dysregulation or mutation of NADK is linked to human diseases,such as cancers,are still not fully understood.Here,we present a cryo-EM structure of human tetrameric NADK and elaborate on the necessity of the NADK tetramer for its activity.The N-terminal region of human NADK,which does not exist in bacterial NADKs,modulates tetramer conformation,thereby regulating its activity.A methylation-deficient mutant,R45H,within the N-terminal region results in increased NADK activity and confers cancer chemotherapy resistance.Conversely,mutations in NADK identified among cancer patients alter the tetramer conformation,resulting in NADK inactivation and increasing the sensitivity of lung cancer cells to chemotherapy.Our findings partially unveil the structural basis for NADK regulation,offering insights into the cancer etiology of patients carrying NADK mutations.
文摘Nicotinamide adenine dinucleotide(NAD^(+))/reduced NAD^(+)(NADH)and nicotinamide adenine dinucleotide phosphate(NADP^(+))/reduced NADP^(+)(NADPH)are essential metabolites involved in multiple metabolic pathways and cellular processes.NAD^(+)and NADH redox couple plays a vital role in catabolic redox reactions,while NADPH is crucial for cellular anabolism and antioxidant responses.Maintaining NAD(H)and NADP(H)homeostasis is crucial for normal physiological activity and is tightly regulated through various mechanisms,such as biosynthesis,consumption,recycling,and conversion between NAD(H)and NADP(H).The conversions between NAD(H)and NADP(H)are controlled by NAD kinases(NADKs)and NADP(H)phosphatases[specifically,metazoan SpoT homolog-1(MESH1)and nocturnin(NOCT)].NADKs facilitate the synthesis of NADP^(+)from NAD^(+),while MESH1 and NOCT convert NADP(H)into NAD(H).In this review,we summarize the physiological roles of NAD(H)and NADP(H)and discuss the regulatory mechanisms governing NAD(H)and NADP(H)homeostasis in three key aspects:the transcriptional and posttranslational regulation of NADKs,the role of MESH1 and NOCT in maintaining NAD(H)and NADP(H)homeostasis,and the influence of the circadian clock on NAD(H)and NADP(H)homeostasis.In conclusion,NADKs,MESH1,and NOCT are integral to various cellular processes,regulating NAD(H)and NADP(H)homeostasis.Dysregulation of these enzymes results in various human diseases,such as cancers and metabolic disorders.Hence,strategies aiming to restore NAD(H)and NADP(H)homeostasis hold promise as novel therapeutic approaches for these diseases.
