Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit th...Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit the stress signals within cells as well as between cells and tissues,and make appropriate adjustments in their growth and development in order to survive and reproduce.In recent years,significant progress has been made on many fronts of the stress signaling research,particularly in understanding the downstream signaling events that culminate at the activation of stress-and nutrient limitation-responsive genes,cellular ion homeostasis,and growth adjustment.However,the revelation of the early events of stress signaling,particularly the identification of primary stress sensors,still lags behind.In this review,we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.展开更多
Brassinosteroids play diverse roles in plant growth and development. Plants deficient in brassinosteroid （BR） biosynthesis or defective in signal transduction show many abnormal developmental phenotypes, indicating ...Brassinosteroids play diverse roles in plant growth and development. Plants deficient in brassinosteroid （BR） biosynthesis or defective in signal transduction show many abnormal developmental phenotypes, indicating the importance of both BR biosynthesis and the signaling pathway in regulating these biological processes. Recently, using genetics, proteomics, genomics, cell biology, and many other approaches, more components involved in the BR signaling pathway were identified. Furthermore, the physiological, cellular, and molecular mechanisms by which BRs regulate various aspects of plant development, are being discovered. These include root development, anther and pollen development and formation, stem elongation, vasculature differentiation, and cellulose biosynthesis, suggesting that the biological functions of BRs are far beyond promoting cell elongation, This review will focus on the up-to-date progresses about regulatory mechanisms of the BR signaling pathway and the physiological and molecular mechanisms whereby BRs regulate plant growth and development.展开更多
It has been almost 20 years since the first report of a WRKY transcription factor, SPF1, from sweet potato. Great progress has been made since then in establishing the diverse biological roles of WRKY transcription fa...It has been almost 20 years since the first report of a WRKY transcription factor, SPF1, from sweet potato. Great progress has been made since then in establishing the diverse biological roles of WRKY transcription factors in plant growth, development, and responses to biotic and abiotic stress. Despite the functional diversity, almost all ana-lyzed WRKY proteins recognize the TrGACC/T W-box sequences and, therefore, mechanisms other than mere recognition of the core W-box promoter elements are necessary to achieve the regulatory specificity of WRKY transcription factors. Research over the past several years has revealed that WRKY transcription factors physically interact with a wide range of proteins with roles in signaling, transcription, and chromatin remodeling. Studies of WRKY-interacting proteins have provided important insights into the regulation and mode of action of members of the important family of transcrip-tion factors. It has also emerged that the slightly varied WRKY domains and other protein motifs conserved within each of the seven WRKY subfamilies participate in protein-protein interactions and mediate complex functional interactions between WRKY proteins and between WRKY and other regulatory proteins in the modulation of important biologi- cal processes. In this review, we summarize studies of protein-protein interactions for WRKY transcription factors and discuss how the interacting partners contribute, at different levels, to the establishment of the complex regulatory and functional network of WRKY transcription factors.展开更多
Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are i...Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are integral to the autophagy process,it is critically important to understand the role of kinases in autophagic regulation.At present,intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease,especially cancer.In this review,we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation.We also summarize the small-molecule kinase inhibitors/activators of these targets,highlighting the opportunities of these new therapeutic agents.展开更多
c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studie...c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studies focused on the structure and function have led to the identification of c-Jun as a basic leucine zipper(bZIP)transcription factor that acts as homo-or heterodimer,binding to DNA and regulating gene transcription.Later on,it was shown that extracellular signals can induce post-translational modifications of c-Jun,resulting in altered transcriptional activity and target gene expression.More recent work has uncovered multiple layers of a complex regulatory scheme in which c-Jun is able to crosstalk,amplify and integrate different signals for tissue development and disease.One example of such scheme is the autocrine amplification loop,in which signal-induced AP-1 activates the c-Jun gene promoter,while increased c-Jun expression feedbacks to potentiate AP-1 activity.Another example of such scheme,based on recent characterization of gene knockout mice,is that c-Jun integrates signals of several developmental pathways,including EGFR-ERK,EGFR-RhoA-ROCK,and activin B-MAP3K1-JNK for embryonic eyelid closure.After more than two decades of extensive research,c-Jun remains at the center stage of a molecular network with mysterious functional properties,some of which are yet to be discovered.In this article,we will provide a brief historical overview of studies on c-Jun regulation and function,and use eyelid development as an example to illustrate the complexity of c-Jun crosstalking with signaling pathways.展开更多
Transforming growth factor β （TGFβ） controls cellular behavior in embryonic and adult tissues. TGFβ binding to serine/threonine kinase receptors on the plasma membrane activates Smad molecules and additional sign...Transforming growth factor β （TGFβ） controls cellular behavior in embryonic and adult tissues. TGFβ binding to serine/threonine kinase receptors on the plasma membrane activates Smad molecules and additional signaling proteins that together regulate gene expression. In this review, mechanisms and models that aim at explaining the coordination between several components of the signaling network downstream of TGFβ are presented. We discuss how the activity and duration of TGFβ receptor/Smad signaling can be regulated by post-translational modifications that affect the stability of key proteins in the pathway. We highlight finks between these mechanisms and human diseases, such as tissue fibrosis and cancer.展开更多
Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracel...Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.展开更多
The last 40 years have witnessed how p53 rose from a viral binding protein to a central factor in both stress responses and tumor suppression.The exquisite regulation of p53 functions is of vital importance for cell f...The last 40 years have witnessed how p53 rose from a viral binding protein to a central factor in both stress responses and tumor suppression.The exquisite regulation of p53 functions is of vital importance for cell fate decisions.Among the multiple layers of mechanisms controlling p53 function,posttranslational modifications (PTMs) represent an efficient and precise way.Major p53 PTMs include phosphorylation,ubiquitination,acetylation,and methylation.Meanwhile,other PTMs like sumoylation,neddylation,O-GlcNAcylation,adenosine diphosphate (ADP)-ribosylation,hydroxylation,and p-hydroxybutyrylation are also shown to play various roles in p53 regulation.By independent action or interaction,PTMs affect p53 stability,conformation,localization,and binding partners.Deregulation of the PTM-related pathway is among the major causes of p53-associated developmental disorders or diseases,especially in cancers.This review focuses on the roles of different p53 modification types and shows how these modifications are orchestrated to produce various outcomes by modulating p53 activities or targeted to treat different diseases caused by p53 dysregulation.展开更多
文摘Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth,productivity and quality.Plants have evolved mechanisms to perceive these environmental challenges,transmit the stress signals within cells as well as between cells and tissues,and make appropriate adjustments in their growth and development in order to survive and reproduce.In recent years,significant progress has been made on many fronts of the stress signaling research,particularly in understanding the downstream signaling events that culminate at the activation of stress-and nutrient limitation-responsive genes,cellular ion homeostasis,and growth adjustment.However,the revelation of the early events of stress signaling,particularly the identification of primary stress sensors,still lags behind.In this review,we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.
文摘Brassinosteroids play diverse roles in plant growth and development. Plants deficient in brassinosteroid （BR） biosynthesis or defective in signal transduction show many abnormal developmental phenotypes, indicating the importance of both BR biosynthesis and the signaling pathway in regulating these biological processes. Recently, using genetics, proteomics, genomics, cell biology, and many other approaches, more components involved in the BR signaling pathway were identified. Furthermore, the physiological, cellular, and molecular mechanisms by which BRs regulate various aspects of plant development, are being discovered. These include root development, anther and pollen development and formation, stem elongation, vasculature differentiation, and cellulose biosynthesis, suggesting that the biological functions of BRs are far beyond promoting cell elongation, This review will focus on the up-to-date progresses about regulatory mechanisms of the BR signaling pathway and the physiological and molecular mechanisms whereby BRs regulate plant growth and development.
文摘It has been almost 20 years since the first report of a WRKY transcription factor, SPF1, from sweet potato. Great progress has been made since then in establishing the diverse biological roles of WRKY transcription factors in plant growth, development, and responses to biotic and abiotic stress. Despite the functional diversity, almost all ana-lyzed WRKY proteins recognize the TrGACC/T W-box sequences and, therefore, mechanisms other than mere recognition of the core W-box promoter elements are necessary to achieve the regulatory specificity of WRKY transcription factors. Research over the past several years has revealed that WRKY transcription factors physically interact with a wide range of proteins with roles in signaling, transcription, and chromatin remodeling. Studies of WRKY-interacting proteins have provided important insights into the regulation and mode of action of members of the important family of transcrip-tion factors. It has also emerged that the slightly varied WRKY domains and other protein motifs conserved within each of the seven WRKY subfamilies participate in protein-protein interactions and mediate complex functional interactions between WRKY proteins and between WRKY and other regulatory proteins in the modulation of important biologi- cal processes. In this review, we summarize studies of protein-protein interactions for WRKY transcription factors and discuss how the interacting partners contribute, at different levels, to the establishment of the complex regulatory and functional network of WRKY transcription factors.
基金supported by grants from National Key R&D Program of China(Grants 2017YFC0909301 and 2017YFC0909302)National Natural Science Foundation of China(Grants 81874290,81673290,81673455,81602953,and 81903502)the Opening Foundation of State Key Laboratory of Pharmaceutical Biotechnology,Nanjing University,China(Grant KF-GN-201904).
文摘Autophagy,defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes,plays a significant role in the quality control of macromolecules and organelles.Since protein kinases are integral to the autophagy process,it is critically important to understand the role of kinases in autophagic regulation.At present,intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease,especially cancer.In this review,we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation.We also summarize the small-molecule kinase inhibitors/activators of these targets,highlighting the opportunities of these new therapeutic agents.
文摘c-Jun,the most extensively studied protein of the activator protein-1(AP-1)complex,is involved in numerous cell activities,such as proliferation,apoptosis,survival,tumorigenesis and tissue morphogenesis.Earlier studies focused on the structure and function have led to the identification of c-Jun as a basic leucine zipper(bZIP)transcription factor that acts as homo-or heterodimer,binding to DNA and regulating gene transcription.Later on,it was shown that extracellular signals can induce post-translational modifications of c-Jun,resulting in altered transcriptional activity and target gene expression.More recent work has uncovered multiple layers of a complex regulatory scheme in which c-Jun is able to crosstalk,amplify and integrate different signals for tissue development and disease.One example of such scheme is the autocrine amplification loop,in which signal-induced AP-1 activates the c-Jun gene promoter,while increased c-Jun expression feedbacks to potentiate AP-1 activity.Another example of such scheme,based on recent characterization of gene knockout mice,is that c-Jun integrates signals of several developmental pathways,including EGFR-ERK,EGFR-RhoA-ROCK,and activin B-MAP3K1-JNK for embryonic eyelid closure.After more than two decades of extensive research,c-Jun remains at the center stage of a molecular network with mysterious functional properties,some of which are yet to be discovered.In this article,we will provide a brief historical overview of studies on c-Jun regulation and function,and use eyelid development as an example to illustrate the complexity of c-Jun crosstalking with signaling pathways.
文摘Transforming growth factor β （TGFβ） controls cellular behavior in embryonic and adult tissues. TGFβ binding to serine/threonine kinase receptors on the plasma membrane activates Smad molecules and additional signaling proteins that together regulate gene expression. In this review, mechanisms and models that aim at explaining the coordination between several components of the signaling network downstream of TGFβ are presented. We discuss how the activity and duration of TGFβ receptor/Smad signaling can be regulated by post-translational modifications that affect the stability of key proteins in the pathway. We highlight finks between these mechanisms and human diseases, such as tissue fibrosis and cancer.
基金Supported by the National Natural Science Foundation of China (No. 30300458)
文摘Objective： To study the effect of salvianolic acid B （SAB） and curcumin, the extracts of Solvie Miltiorrhize and Curcume Longe, on the proliferation and activation of hepatic stellate cell （HSC）, and the extracellular signal regulated kinase （ERK） expression in it. Methods： Rat＇s HSC-T6 were cultured and treated by SAB or curcumin. The inhibitory effect on cell proliferation was determined by 3-（4,5-dimthyl-2- 2thiazoly）-2,5-diphenyl-2H-tetrazolium bromide （MTT） colorimetry, and the expression levels of a smooth actin （a-SMA）, collagen type Ⅰ , and ERK were determined by Western blot. Results： SAB and curcumin inhibited the proliferation and activation of rat＇s HSC-T6 in dose-dependent fashion and significantly reduced the expression level of a-SMA （ P〈0.01 ）. Curcumin significantly reduced the expression of collagen type Ⅰ （P〈0.05）. Both SAB and curcumin showed insignificant effect on the ERK expression level, but they could significantly reduce the level of phosphorylated-ERK expression, showing significant difference as compared with that in the control group （ P〈0.01 and P〈0.05 respectively）. Conclusion： SAB and curcumin could significantly inhibit the proliferation, activation of HSC, and the production of type Ⅰ collagen in HSC, the mechanism may be associated with their inhibition on ERK phosphorylation.
文摘The last 40 years have witnessed how p53 rose from a viral binding protein to a central factor in both stress responses and tumor suppression.The exquisite regulation of p53 functions is of vital importance for cell fate decisions.Among the multiple layers of mechanisms controlling p53 function,posttranslational modifications (PTMs) represent an efficient and precise way.Major p53 PTMs include phosphorylation,ubiquitination,acetylation,and methylation.Meanwhile,other PTMs like sumoylation,neddylation,O-GlcNAcylation,adenosine diphosphate (ADP)-ribosylation,hydroxylation,and p-hydroxybutyrylation are also shown to play various roles in p53 regulation.By independent action or interaction,PTMs affect p53 stability,conformation,localization,and binding partners.Deregulation of the PTM-related pathway is among the major causes of p53-associated developmental disorders or diseases,especially in cancers.This review focuses on the roles of different p53 modification types and shows how these modifications are orchestrated to produce various outcomes by modulating p53 activities or targeted to treat different diseases caused by p53 dysregulation.
基金This work was supported by the National Natural Science Foundation of China (No.30271611) the Key Science and Technology Research Project of Fujian Province (No.2003F009).
