The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve...The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.展开更多
Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, o...Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.展开更多
The mitogen_activated protein (MAP) kinase cascades are composed of mitogen_activated protein kinases (MAPKs), mitogen_activated protein kinase kinases (MAPKKs) and mitogen_activated protein kinase kinase kinases (MAP...The mitogen_activated protein (MAP) kinase cascades are composed of mitogen_activated protein kinases (MAPKs), mitogen_activated protein kinase kinases (MAPKKs) and mitogen_activated protein kinase kinase kinases (MAPKKKs), they transfer signals through phosphorylations of MAPKKK→MAPKK→MAPK. MAP kinases include a large family of serine/threonine protein kinases which are structurally conserved in eukaryotes. MAP kinase cascades play essential roles in signal transductions of extracellular signals to intracellular targets in eukaryotes. Some MAPKs, MAPKKs and MAPKKKs have been isolated from the higher plants, they mediate the signal transductions involved in plant responses to hormones, cell proliferation and differentiation, and environmental stresses.展开更多
运用表皮条生物学分析、激光共聚焦扫描及膜片钳技术,在MEK1/2和p38MAP激酶专一性抑制剂PD98059和SB203580处理下,观察促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAP激酶)家族成员介导蚕豆保卫细胞中氧化信号机制.结果表...运用表皮条生物学分析、激光共聚焦扫描及膜片钳技术,在MEK1/2和p38MAP激酶专一性抑制剂PD98059和SB203580处理下,观察促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAP激酶)家族成员介导蚕豆保卫细胞中氧化信号机制.结果表明,PD98059能阻断并逆转ABA和H2O2抑制质膜内向K+电流、ABA诱导H2O2产生及气孔关闭,SB203580也表现相似的作用.因此,两种MAP激酶可能共同调节ABA诱导ROS产生和气孔关闭.展开更多
OBJECTIVE: To explore the effects of evodiamine on ovarian cancer cells and the mechanisms underlying such effects.METHODS: Human ovarian cancer cells HO-8910 PM were treated with evodiamine at 0, 1.25,2.5, and 5 μM ...OBJECTIVE: To explore the effects of evodiamine on ovarian cancer cells and the mechanisms underlying such effects.METHODS: Human ovarian cancer cells HO-8910 PM were treated with evodiamine at 0, 1.25,2.5, and 5 μM for 1-4 d. 3-(4,5-Dimethiylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was used to detect the growth inhibition rate of evodiamine-treated HO-8910 PM cells. The cell cycle was observed via propidium iodide(PI) staining. Apoptosis induction was assessed via Annexin V-fluorescein isothiocyanate/propidium iodide(Annexin V-FITC/PI) double staining assay. To verify the mechanism of apoptosis, caspase-dependent apoptotic pathway-related protein was detected by Western blot analysis. The expression levels of mitogen-activated protein kinase(MAPK)and/or phosphatidylinositol-3-kinase(PI3K)/pro-tein kinase B(Akt) pathway-related proteins were also investigated.RESULTS: Evodiamine significantly inhibited the proliferation of HO-8910 PM cells in a dose- and time-dependent manner. Evodiamine induced G2/M arrest with an increase of cyclin B1 level, and promoted cell apoptosis with a decrease of B cell lymphoma/lewkmia-2(Bcl-2) and an increase of Bcl-2-associated X protein(Bax) level. In addition,evodiamine treatment led to the activation of caspase-8, caspase-9, and caspase-3 and the cleavage of poly(ADP-ribose)-polymerase(PARP). Evodiamine targeted the MAPK and/or PI3K/Akt pathways by reducing the expression and activity of PI3 K, Akt, and extracellular signal-regulated kinase mitogen-activated protein kinase(ERK1/2 MAPK)and the activity of p38 MAPK.CONCLUSION: Evodiamine can inhibit the growth of ovarian cancer cells by G2/M arrest and intrinsic and extrinsic apoptosis. In addition, evodiamine-induced PI3K/Akt, ERK1/2 MAPK, and p38 MAPK signaling may be involved in cell death.展开更多
文摘The family members of the mitogen-activated protein (MAP) kinases mediate a wide variety of cellular behaviors in response to extracellular stimuli. One of the four main sub-groups, the p38 group of MAP kinases, serve as a nexus for signal transduction and play a vital role in numerous biological processes. In this review, we highlight the known characteristics and components of the p38 pathway along with the mechanism and consequences of p38 activation. We focus on the role of p38 as a signal transduction mediator and examine the evidence linking p38 to inflammation, cell cycle, cell death, development, cell differentiation, senescence and tumorigenesis in specific cell types. Upstream and downstream components of p38 are described and questions remaining to be answered are posed. Finally, we propose several directions for future research on p38.
文摘Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.
文摘目的 :探讨组蛋白去甲基化酶JMJD2B影响人结直肠癌细胞恶性表型所介导的信号通路。方法 :以RNA干扰技术靶向沉默人结直肠癌细胞HCT116和SW480中JMJD2B的表达,采用蛋白质印迹法检测人结直肠癌细胞ERK-MAPK信号通路的变化,并分别采用CCK-8、流式细胞分析检测细胞增殖和细胞周期分布、凋亡情况。结果:转染JMJD2B si RNA能特异性抑制JMJD2B的表达并导致ERK2表达下调,其磷酸化水平也降低,肿瘤细胞发生G2/M或G0/G1期阻滞,细胞凋亡比例增加,增殖显著受抑(P<0.05)。结论:抑制JMJD2B可通过阻断ERK-MAPK信号转导而抑制人结直肠癌细胞的恶性表型。
文摘The mitogen_activated protein (MAP) kinase cascades are composed of mitogen_activated protein kinases (MAPKs), mitogen_activated protein kinase kinases (MAPKKs) and mitogen_activated protein kinase kinase kinases (MAPKKKs), they transfer signals through phosphorylations of MAPKKK→MAPKK→MAPK. MAP kinases include a large family of serine/threonine protein kinases which are structurally conserved in eukaryotes. MAP kinase cascades play essential roles in signal transductions of extracellular signals to intracellular targets in eukaryotes. Some MAPKs, MAPKKs and MAPKKKs have been isolated from the higher plants, they mediate the signal transductions involved in plant responses to hormones, cell proliferation and differentiation, and environmental stresses.
文摘运用表皮条生物学分析、激光共聚焦扫描及膜片钳技术,在MEK1/2和p38MAP激酶专一性抑制剂PD98059和SB203580处理下,观察促分裂原活化蛋白激酶(mitogen-activated protein kinase,MAP激酶)家族成员介导蚕豆保卫细胞中氧化信号机制.结果表明,PD98059能阻断并逆转ABA和H2O2抑制质膜内向K+电流、ABA诱导H2O2产生及气孔关闭,SB203580也表现相似的作用.因此,两种MAP激酶可能共同调节ABA诱导ROS产生和气孔关闭.
文摘OBJECTIVE: To explore the effects of evodiamine on ovarian cancer cells and the mechanisms underlying such effects.METHODS: Human ovarian cancer cells HO-8910 PM were treated with evodiamine at 0, 1.25,2.5, and 5 μM for 1-4 d. 3-(4,5-Dimethiylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was used to detect the growth inhibition rate of evodiamine-treated HO-8910 PM cells. The cell cycle was observed via propidium iodide(PI) staining. Apoptosis induction was assessed via Annexin V-fluorescein isothiocyanate/propidium iodide(Annexin V-FITC/PI) double staining assay. To verify the mechanism of apoptosis, caspase-dependent apoptotic pathway-related protein was detected by Western blot analysis. The expression levels of mitogen-activated protein kinase(MAPK)and/or phosphatidylinositol-3-kinase(PI3K)/pro-tein kinase B(Akt) pathway-related proteins were also investigated.RESULTS: Evodiamine significantly inhibited the proliferation of HO-8910 PM cells in a dose- and time-dependent manner. Evodiamine induced G2/M arrest with an increase of cyclin B1 level, and promoted cell apoptosis with a decrease of B cell lymphoma/lewkmia-2(Bcl-2) and an increase of Bcl-2-associated X protein(Bax) level. In addition,evodiamine treatment led to the activation of caspase-8, caspase-9, and caspase-3 and the cleavage of poly(ADP-ribose)-polymerase(PARP). Evodiamine targeted the MAPK and/or PI3K/Akt pathways by reducing the expression and activity of PI3 K, Akt, and extracellular signal-regulated kinase mitogen-activated protein kinase(ERK1/2 MAPK)and the activity of p38 MAPK.CONCLUSION: Evodiamine can inhibit the growth of ovarian cancer cells by G2/M arrest and intrinsic and extrinsic apoptosis. In addition, evodiamine-induced PI3K/Akt, ERK1/2 MAPK, and p38 MAPK signaling may be involved in cell death.
