Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several cytokines and LPS regulate the population of the B1 receptors (B1Rs) for kinins; these are responsive to des-Arg9-bradykinin (BK) and Lys-des-Arg9-BK. B1R activation contributes to inflammatory vascular changes and pain. Aortic rings isolated from normal rabbits and incubated in vitro in Krebs physiological medium were used as a model of tissue injury. From a null level of response, these rings exhibit a time- and protein synthesis-dependent increase in the maximal contractile response to des-Arg9-BK. Exposure to exogenous IL-1beta or epidermal growth factor (EGF) considerably increases the process of sensitization to the kinins. Freshly isolated control aortic rings showed high mitogen-activated protein (MAP) kinase activities (persistent activation of p38, but less prolonged for extracellular signal-regulated kinase and c-Jun-N-terminal kinase/stress-activated protein kinase pathways) relatively to the basal activities found in various types of cultured cells. IL-1beta or EGF further increased the activities of the extracellular signal-regulated kinase and c-Jun-N-terminal kinase/stress-activated protein kinase MAP kinases. The inhibitor of the p38 MAP kinase, SB 203580 (10 microM), massively (approximately 75%) and selectively inhibited the spontaneous sensitization to des-Arg9-BK over 6 h. SB 203580 also significantly reduced the development of the response to des-Arg9-BK as stimulated by IL-1 or EGF. Both spontaneous and IL-1beta-stimulated up-regulation of responsiveness to des-Arg9-BK were significantly inhibited by the MAP kinase extracellular signal-regulated kinase kinase 1 inhibitor PD 98059 (approximately 40%). The protein kinase inhibitors failed to inhibit protein synthesis and to acutely inhibit the contractile effect of des-Arg9-BK, suggesting that they do not influence B1 receptor transduction mechanisms. In cultured aortic smooth muscle cells stimulated with EGF, MAP kinase activation preceded B1R mRNA induction. Protein kinase inhibitors reveal the role of cell injury-controlled MAP kinase pathways, and singularly of the p38 pathway, in the induction of B1R.
 ...
PMID:Role of the mitogen-activated protein kinases in the expression of the kinin B1 receptors induced by tissue injury. 957 May 62

The fission yeast Sty1 stress-activated MAP kinase is crucial for the cellular response to a variety of stress conditions. Accordingly, sty1- cells are defective in their response to nutrient limitation, lose viability in stationary phase, and are hypersensitive to osmotic stress, oxidative stress, and UV treatment. Some of these phenotypes are caused by Sty1-dependent regulation of the Atf1 transcription factor, which controls both meiosis-specific and osmotic stress-responsive genes. However, in this report we demonstrate that the cellular response to oxidative stress and to treatment with a variety of cytotoxic agents is the result of Sty1 regulation of the Pap1 transcription factor, a bZip protein with structural and DNA binding similarities to the mammalian c-Jun protein. We show that both Sty1 and Pap1 are required for the expression of a number of genes involved in the oxidative stress response and for the expression of two genes, hba2+/bfr1+ and pmd1+, which encode energy-dependent transport proteins involved in multidrug resistance. Furthermore, we demonstrate that Pap1 is regulated by stress-dependent changes in subcellular localization. On imposition of oxidative stress, the Pap1 protein relocalizes from the cytoplasm to the nucleus in a process that is dependent on the Sty1 kinase. This relocalization is the result of regulated protein export, rather than import, and involves the Crm1 (exportin) nuclear export factor and the dcd1+/pim1+ gene that encodes an Ran nucleotide exchange factor.
 ...
PMID:Regulation of the fission yeast transcription factor Pap1 by oxidative stress: requirement for the nuclear export factor Crm1 (Exportin) and the stress-activated MAP kinase Sty1/Spc1. 958 99

MAP kinase phosphatase-3 (MKP-3) dephosphorylates phosphotyrosine and phosphothreonine and inactivates selectively ERK family mitogen-activated protein (MAP) kinases. MKP-3 was activated by direct binding to purified ERK2. Activation was independent of protein kinase activity and required binding of ERK2 to the noncatalytic amino-terminus of MKP-3. Neither the gain-of-function Sevenmaker ERK2 mutant D319N nor c-Jun amino-terminal kinase-stress-activated protein kinase (JNK/SAPK) or p38 MAP kinases bound MKP-3 or caused its catalytic activation. These kinases were also resistant to enzymatic inactivation by MKP-3. Another homologous but nonselective phosphatase, MKP-4, bound and was activated by ERK2, JNK/SAPK, and p38 MAP kinases. Catalytic activation of MAP kinase phosphatases through substrate binding may regulate MAP kinase activation by a large number of receptor systems.
 ...
PMID:Catalytic activation of the phosphatase MKP-3 by ERK2 mitogen-activated protein kinase. 963 2

Kaposi's sarcoma (KS) spindle cell growth and spread have been reported to be modulated by various cytokines as well as the human immunodeficiency virus (HIV) gene product Tat. Recently, HIV-1 Tat has been shown to act like a cytokine and bind to the Flk-1/KDR receptor for the vascular endothelial growth factor A (VEGF-A), which is expressed by KS cells. We have characterized signal transduction pathways stimulated by HIV-1 Tat upon its binding to surface receptors on KS cells. We observed that stimulation in KS 38 spindle cells resulted in tyrosine phosphorylation and activation of the Flk-1/KDR receptor. We also report that HIV-1 Tat treatment enhanced the phosphorylation and association of proteins found in focal adhesions, such as the related adhesion focal tyrosine kinase RAFTK, paxillin, and p130(cas). Further characterization revealed the activation of mitogen-activated protein kinase, c-Jun amino-terminal kinase (JNK), and Src kinase. HIV-1 Tat contains a basic domain which can interact with growth factor tyrosine kinase receptors and a classical RGD sequence which may bind to and activate the surface integrin receptors for fibronectin and vitronectin. We observed that stimulation of KS cells with basic as well as RGD sequence-containing Tat peptides resulted in enhanced phosphorylation of RAFTK and activation of MAP kinase. These studies reveal that Tat stimulation activates a number of signal transduction pathways that are associated with cell growth and migration.
 ...
PMID:Human immunodeficiency virus tat modulates the Flk-1/KDR receptor, mitogen-activated protein kinases, and components of focal adhesion in Kaposi's sarcoma cells. 962 Oct 77

We have investigated the mechanisms underlying regulation of the calcitonin gene-related peptide (CGRP) cell-specific enhancer. Recently, we reported that this enhancer is inhibited by serotonin type-1 (5-HT1) agonists, similar to currently used antimigraine drugs. We have now tested whether this repression involves a mitogen-activated protein (MAP) kinase pathway. We first demonstrate that the CGRP enhancer is strongly (10-fold) activated by a constitutively active MAP kinase kinase (MEK1), yielding reporter activities 100-fold above the enhancerless control. The involvement of a MAP kinase pathway was confirmed by down-regulation of reporter activity upon cotransfection of a dominant negative Ras. Activation of the enhancer by MEK1 was blocked in a dose-dependent manner by the 5-HT1 receptor agonist CGS 12066A (CGS). Since it is not known whether the CGRP enhancer factors are immediate targets of MAP kinases, we then used EIk-1- and c-Jun-dependent reporter genes that are directly activated by the ERK (extracellular signal-regulated kinases) and JNK (c-Jun N-terminal kinase) MAP kinases. CGS treatment repressed the activation of both of these reporters, suggesting that at least two MAP kinases are the immediate targets of CGS-mediated repression. We further demonstrate that 5-HT1 agonists inactivate ERK by dephosphorylation, even in the presence of constitutively activated MEK1. This inactivation appears to be due to a marked increase in the level of MAP kinase phosphatase-1. These results have defined a novel and general mechanism by which 5-HT1 receptor agonists can repress MAP kinase activation of target genes, such as CGRP.
 ...
PMID:Serotonergic repression of mitogen-activated protein kinase control of the calcitonin gene-related peptide enhancer. 965 4

UV irradiation leads to severe damage, such as cutaneous inflammation, immunosuppression, and cancer, but it also results in a gene induction protective response termed the UV response. The signal triggering the UV response was thought to originate from DNA damage; recent findings, however, have shown that it is initiated at or near the cell membrane and transmitted via cytoplasmic kinase cascades to induce gene transcription. Urokinase-type plasminogen activator (uPA) was the first protein shown to be UV inducible in xeroderma pigmentosum DNA repair-deficient human cells. However, the underlying molecular mechanisms responsible for the induction were not elucidated. We have found that the endogenous murine uPA gene product is transcriptionally upregulated by UV in NIH 3T3 fibroblast and F9 teratocarcinoma cells. This induction required an activator protein 1 (AP1) enhancer element located at -2.4 kb, since deletion of this site abrogated the induction. We analyzed the contribution of the three different types of UV-inducible mitogen-activated protein (MAP) kinases (ERK, JNK/SAPK, and p38) to the activation of the murine uPA promoter by UV. MEKK1, a specific JNK activator, induced transcription from the uPA promoter in the absence of UV treatment, whereas coexpression of catalytically inactive MEKK1(K432M) and of cytoplasmic JNK inhibitor JIP-1 inhibited UV-induced uPA transcriptional activity. In contrast, neither dominant negative MKK6 (or SB203580) nor PD98059, which specifically inhibit p38 and ERK MAP kinase pathways, respectively, could abrogate the UV-induced effect. Moreover, our results indicated that wild-type N-terminal c-Jun, but not mutated c-Jun (Ala-63/73), was able to mediate UV-induced uPA transcriptional activity. Taken together, we show for the first time that kinases of the JNK family can activate the uPA promoter. This activation links external UV stimulation and AP1-dependent uPA transcription, providing a transcription-coupled signal transduction pathway for the induction of the murine uPA gene by UV.
 ...
PMID:UV irradiation induces the murine urokinase-type plasminogen activator gene via the c-Jun N-terminal kinase signaling pathway: requirement of an AP1 enhancer element. 967 63

This communication describes an extracellular signal-regulated kinase kinase (MEK)-dependent signal transduction pathway that prevents the terminal differentiation of a hemopoietic cell line. Both PMA and the cell-permeable ceramide, C2-ceramide, caused differentiation of U937 cells, but with distinct cell morphology and CD11b/CD14 surface expression. While PMA activated extracellular signal-regulated kinase (ERK), a downstream kinase of Raf-MEK signaling, C2-ceramide activated c-Jun NH2-terminal kinase (JNK), an anchor kinase of stress-induced signaling. Furthermore, only C2-ceramide stimulated an induction of cell cycle arrest that was associated with stable expression of p21CIP1 and retinoblastoma nuclear phosphoprotein dephosphorylation. Expression of p21CIP1 and JNK activation were also observed in sphingosine-treated cells, whereas sphingosine did not induce detectable differentiation. Concomitant stimulation with C2-ceramide and PMA resulted in the PMA phenotype, and cell cycle arrest was absent. ERK activation was enhanced by C2-ceramide plus PMA stimulation, whereas the activation of JNK was aborted. Strikingly, the inhibition of MEK with PD98059 altered the phenotype of C2-ceramide- and PMA-stimulated U937 cells to that of cells treated with C2-ceramide alone. Thus, ERK and JNK pathways deliver distinct signals, and the ERK pathway is dominant to the JNK cascade. Furthermore, differentiation and cell cycle arrest caused by C2-ceramide rely on independent signaling pathways, and JNK is an unlikely signaling element for this differentiation. Importantly, during C2-ceramide and PMA costimulation, the JNK pathway is not simply blocked by ERK activation; rather, cross-talk between these MAP kinase pathways acts to simultaneously augment ERK activity and down-regulate JNK activity.
 ...
PMID:The mitogen-activated protein kinase pathway inhibits ceramide-induced terminal differentiation of a human monoblastic leukemia cell line, U937. 968 2

The mitogen-activated protein (MAP) kinase signaling pathways are believed to act as critical signal transducers between stress stimuli and transcriptional responses in mammalian cells. However, it is not known whether these signaling cascades also participate in the response to injury in human tissues. To determine whether injury to the vastus lateralis muscle activates MAP kinase signaling in human subjects, two needle biopsies or open muscle biopsies were taken from the same incision site 30-60 min apart. The muscle biopsy procedures resulted in striking increases in dual phosphorylation of the extracellular-regulated kinases (ERK1 and ERK2) and in activity of the downstream substrate, the p90 ribosomal S6 kinase. Raf-1 kinase and MAP kinase kinase, upstream activators of ERK, were also markedly stimulated in all subjects. In addition, c-Jun NH2-terminal kinase and p38 kinase, components of two parallel MAP kinase pathways, were activated following muscle injury. The stimulation of the three MAP kinase cascades was present only in the immediate vicinity of the injury, a finding consistent with a local rather than systemic activation of these signaling cascades in response to injury. These data demonstrate that muscle injury induces the stimulation of the three MAP kinase cascades in human skeletal muscle, suggesting a physiological relevance of these protein kinases in the immediate response to tissue injury and possibly in the initiation of wound healing.
 ...
PMID:Extracellular-regulated protein kinase cascades are activated in response to injury in human skeletal muscle. 968 10

Pulmonary hypertension in response to chronic hypoxia is invariably accompanied by remodeling of the pulmonary vessels but the mechanism by which hypoxia increases the replication of vascular cells is unknown. To investigate the hypothesis that hypoxia stimulates intracellular kinase cascades we measured the activity of "classic" mitogen-activated protein (MAP) kinase pathways and "stress- activated" MAP kinase pathways in bovine pulmonary artery fibroblasts subjected to hypoxia for up to 30 h. Hypoxia (1% O2) stimulated strongly the stress-activated protein kinases, c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase. Two peaks of p38 MAP kinase activity at 6 and 24 h were associated with an increase in the activity of mitogen-activated protein kinase-activated protein (MAPKAP) kinase-2, the immediate downstream target of p38 MAP kinase. Furthermore, the second phase of p38 MAP kinase activity could be reversed if cells were reoxygenated after 12 h. These data suggest that hypoxic stimulation of pulmonary artery cells is mediated by activation of the stress-activated protein kinases.
 ...
PMID:Hypoxic stimulation of the stress-activated protein kinases in pulmonary artery fibroblasts. 973 Oct 31

Ultraviolet radiation from the sun damages human skin, resulting in an old and wrinkled appearance. A substantial amount of circumstantial evidence indicates that photoaging results in part from alterations in the composition, organization, and structure of the collagenous extracellular matrix in the dermis. This paper reviews the authors' investigations into the molecular mechanisms by which ultraviolet irradiation damages the dermal extracellular matrix and provides evidence for prevention of this damage by all-trans retinoic acid in human skin in vivo. Based on experimental evidence a working model is proposed whereby ultraviolet irradiation activates growth factor and cytokine receptors on keratinocytes and dermal cells, resulting in downstream signal transduction through activation of MAP kinase pathways. These signaling pathways converge in the nucleus of cells to induce c-Jun, which heterodimerizes with constitutively expressed c-Fos to form activated complexes of the transcription factor AP-1. In the dermis and epidermis, AP-1 induces expression of matrix metalloproteinases collagenase, 92 kDa gelatinase, and stromelysin, which degrade collagen and other proteins that comprise the dermal extracellular matrix. It is hypothesized that dermal breakdown is followed by repair that, like all wound repair, is imperfect. Imperfect repair yields a deficit in the structural integrity of the dermis, a solar scar. Dermal degradation followed by imperfect repair is repeated with each intermittent exposure to ultraviolet irradiation, leading to accumulation of solar scarring, and ultimately visible photoaging. All-trans retinoic acid acts to inhibit induction of c-Jun protein by ultraviolet irradiation, thereby preventing increased matrix metalloproteinases and ensuing dermal damage.
 ...
PMID:Molecular mechanisms of photoaging and its prevention by retinoic acid: ultraviolet irradiation induces MAP kinase signal transduction cascades that induce Ap-1-regulated matrix metalloproteinases that degrade human skin in vivo. 973 61


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>