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Query: DrugBank:BIOD00035 (
CSF
)
30,988
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Granulocyte-macrophage colony-stimulating factor (GM-CSF), Interleukin-3 (IL-3), and Steel Factor (SF) induce proliferation of hematopoietic cells through binding to specific, high-affinity, cell surface receptors. However, little is known about postreceptor signal transduction pathways. In previous studies, we noted that each of these three factors could independently support proliferation of the human MO7 cell line, and also that each factor induced a rapid increase in protein-tyrosyl phosphorylation. Although the proteins phosphorylated on tyrosine by GM-CSF and IL-3 are similar or identical in MO7 cells, many of the proteins that are phosphorylated on tyrosine after SF are different. However, two proteins, p42 and p44, were prominently phosphorylated in response to all three of the factors. In MO7 cells, the tyrosyl phosphorylation of p42 and p44 was transient, peaking at 5 to 15 minutes. In contrast to many of the other proteins which are tyrosyl phosphorylated in response to these factors, phosphorylation of p42 and p44 was temperature-dependent, occurring at 37 degrees C, but not at 4 degrees C. We identified the p42 protein as p42 Mitogen-Activated Protein Kinase (
p42mapk
, ERK-2) and the p44 as a
p42mapk
-related protein using monospecific antisera to
MAP kinase
. GM-CSF, IL-3, and SF were each found to induce
MAP kinase
activity when assayed in vitro using myelin basic protein (MBP) as a substrate. Remarkably, we found that GM-CSF-induced tyrosyl phosphorylation of p42 and p44 even in nonproliferative cells (neutrophils) that respond to this
CSF
, and that p42 and p44 were two of the most prominently tyrosyl phosphorylated proteins following GM-CSF stimulation of these cells. These results implicate
p42mapk
and p44 as important signal transducing molecules in myeloid cells, and it is likely that these kinases play a role as part of a sequential "kinase cascade" linking growth factor receptors to mitogenesis and other cellular responses.
...
PMID:Granulocyte-macrophage colony-stimulating factor, interleukin-3, and steel factor induce rapid tyrosine phosphorylation of p42 and p44 MAP kinase. 137 18
Stimulation of hemopoietic cells with IL-3, IL-4, IL-5, granulocyte-macrophage-
CSF
and Steel factor-(SLF) induced tyrosine phosphorylation of a number of protein substrates. Two of these proteins, designated p42 and p44, were tyrosine phosphorylated rapidly in response to treatment with IL-3, IL-5, granulocyte-macrophage-
CSF
and SLF, but not IL-4. We demonstrate that these common substrates are members of the
mitogen-activated protein kinase
(
MAP kinase
) family of protein serine/threonine kinases. Ion-exchange chromatography yielded a peak of
MAP kinase
activity eluting at 0.3 to 0.32 M NaCl. Immunoblotting of column fractions with antiphosphotyrosine antibodies showed coelution of the peak of
MAP kinase
enzyme activity with the p42 and p44 tyrosine phosphorylated species, and with two proteins of 42 and 44 kDa which were immunoreactive with anti-
MAP kinase
antibodies. Moreover, a characteristic shift in mobility of the p42 and p44 species was observed after factor treatment. Time-course analyses and subsequent ion-exchange chromatography demonstrated SLF activation of
MAP kinase
activity was maximal after 2 min of factor treatment and decreased to basal levels after 30 min stimulation. By contrast, activation of
MAP kinase
after IL-5 treatment was not as rapid. Maximal activity was observed 15 min after stimulation and remained elevated for up to 60 min after IL-5 addition. Investigation of the role of protein kinase C in the mechanism of activation by these growth factors demonstrated that specific inhibition of protein kinase C led to a reduction, but not ablation, of the SLF and IL-3 induced stimulation of
MAP kinase
activity. The use of synthetic peptide substrates confirmed SLF and IL-5 activate isoforms of MAP kinases. These results demonstrate that members of the
MAP kinase
family are involved in common signal transduction events elicited by IL-3, IL-5, granulocyte-macrophage-
CSF
and Steel factor, but not those involving IL-4.
...
PMID:Multiple hemopoietic growth factors stimulate activation of mitogen-activated protein kinase family members. 138 May 36
Steel factor (SF), the ligand for the proto-oncogene c-kit, acts synergistically with
GM-CSF
or IL-3 to support the growth of normal human hematopoietic progenitor cells. We examined the effects of SF on
GM-CSF
or IL-3 induced proliferation of a human factor-dependent cell line, MO7. SF supported MO7 cell proliferation as well as IL-3 or
GM-CSF
alone, and its addition dramatically enhanced (three- to sixfold) maximal
GM-CSF
or IL-3 stimulated proliferation. SF did not increase the number or affinity of cell surface
GM-CSF
receptors. We examined several early events of signal transduction in an effort to elucidate the biochemical mechanisms of synergy of these factors. Since each of these three cytokines is believed to function in part through activation of a tyrosine kinase, we examined their effects on cellular phosphotyrosine containing proteins. Each cytokine induced rapid, transient, and concentration dependent tyrosine phosphorylation of a number of substrates. For
GM-CSF
and IL-3, these phosphoproteins were indistinguishable (150, 125, 106, 93, 80, 79, 73, 44, 42, and 36 kDa), while SF induced major or minor tyrosine phosphorylation of 205, 140-150, 116, 106, 94, 90, 80, 79, 73, 44, 42, 39, 36, 32 kDa phosphoproteins. Two other signal transduction intermediates known to be phosphorylated and activated by
GM-CSF
and IL-3, the 70-75 kDa Raf-1 kinase, and
p42 mitogen-activated protein kinase
-2 (MAPK), were also phosphorylated by SF. Combinations of
GM-CSF
or IL-3 with SF did not further increase the phosphorylation of Raf-1 or p42 MAPK when compared to any of the factors alone. In contrast SF, but not
GM-CSF
or IL-3, induced tyrosine phosphorylation of phospholipase C-gamma (PLC-gamma). These results indicate that SF and
GM-CSF
/IL-3 have partially overlapping effects on early signal transducing events, as well as striking differences, such as tyrosine phosphorylation of PLC-gamma. This cell line should provide a useful model system to investigate the complicated process of hematopoietic growth factor synergy.
...
PMID:Granulocyte-macrophage colony-stimulating factor and steel factor induce phosphorylation of both unique and overlapping signal transduction intermediates in a human factor-dependent hematopoietic cell line. 138 14
The addition of the chemotactic peptide formylmethionylleucylphenylalanine (fMet-Leu-Phe) to human neutrophils pretreated with the cytokine granulocyte/macrophage colony-stimulating factor (GM-CSF) results in a 10-fold enhanced activity of phospholipase A2, measured as the release of arachidonic acid. It is found that GM-
CSF
increases the tyrosine phosphorylation, enhances the activity of a
mitogen-activated protein kinase
, and greatly potentiates the fMet-Leu-Phe-induced tyrosine phosphorylation and enhanced activity of this kinase. Stimuli that increase the tyrosine phosphorylation, enhance the activity of the
mitogen-activated protein kinase
, and cause a rise in the intracellular concentration of free calcium increase the amount of phospholipase A2 associated with the plasma membrane. This increase corresponds to a decrease in the amount found in the cytosol. Whereas GM-
CSF
alone produces only a small increase in the amount of phospholipase A2 associated with the membrane, it potentiates greatly the fMet-Leu-Phe-induced increase. The total amount (whole cell) of phospholipase A2, as measured by immunoblotting using anti-phospholipase A2 antibody, does not change upon stimulation of human neutrophils with GM-
CSF
, fMet-Leu-Phe, or both. In addition, the band that corresponds to phospholipase A2 is shifted upward in membrane isolated from neutrophils stimulated with fMet-Leu-Phe, suggesting that the enzyme has been altered, possibly phosphorylated, though not on tyrosine residues. A working hypothesis is presented. Briefly, stimulation of human neutrophils with GM-
CSF
, in the absence of an additional stimulus, increases the tyrosine phosphorylation and activation of a
mitogen-activated protein kinase
, which in turn phosphorylates and activates cytoplasmic phospholipase A2. In the presence of an increased intracellular concentration of free calcium the phospholipase A2 is translocated to the plasma membrane where its substrate is located. GM-
CSF
also potentiates greatly the fMet-Leu-Phe-induced tyrosine phosphorylation and activation of a
mitogen-activated protein kinase
and, since fMet-Leu-Phe causes an intracellular calcium rise, the amount of the phospholipase A2 that is associated with the membrane fraction.
...
PMID:Cytoplasmic phospholipase A2 translocates to membrane fraction in human neutrophils activated by stimuli that phosphorylate mitogen-activated protein kinase. 751 25
The high affinity receptor for
GM-CSF
consists of a unique alpha subunit and a beta subunit that is shared with receptors for IL-3 and IL-5. Activation of GM-CSF receptor (GMR) triggers two distinct cytoplasmic signalling pathways, JAK2 and Ras, and is sufficient to maintain proliferation of growth factor-dependent cell lines. Shc proteins are phosphorylated upon activation of GMR and may be involved in the transmission of
GM-CSF
signals to Ras. To define the role of Shc proteins in cells stimulated with
GM-CSF
, we investigated both the network of interactions that involve Shc after
GM-CSF
stimulation and the effects of overexpressing Shc proteins on the proliferative response to
GM-CSF
. Two cytoplasmic complexes, Grb2/Sos and Grb2/p140 bind through the Grb2 SH2 domain to phosphorylated Shc, and are thereby recruited to the beta subunit. Both complexes are stable, even in the absence of ligand, and depend on the direct association of p140 and Sos respectively with the SH3 domains of Grb2. p140 is an uncharacterized protein constitutively phosphorylated on tyrosine and, in its Grb2-bound form, expressed only in hematopoietic cells, the oligomeric complex formed by phosphorylated beta subunit-phosphorylated Shc-Grb2-SoS-p140 is also induced by IL-3 and L-5 stimulation of growth-factor dependent cell lines. Overexpression of wild-type Shc proteins in growth factor-dependent cells increases both
MAP kinase
activation and proliferation in response to
GM-CSF
. These effects require the association of Shc with Grb2. Taken together these results indicate that phosphorylation of Shc proteins is a crucial step in the transmission of
GM-CSF
proliferative stimuli, since it creates a high affinity binding site for the Grb2/SoS complex, whose function is to activate Ras and, for the Grb2/p140 complex, whose function remains unknown.
...
PMID:Overexpression of Shc proteins potentiates the proliferative response to the granulocyte-macrophage colony-stimulating factor and recruitment of Grb2/SoS and Grb2/p140 complexes to the beta receptor subunit. 789 32
Nyk/Mer is a recently identified receptor tyrosine kinase with neural cell adhesion molecule-like structure (two immunoglobulin G-like domains and two fibronectin III-like domains) in its extracellular region and belongs to the Ufo/Axl family of receptors. The ligand for Nyk/Mer is presently unknown, as are the signal transduction pathways mediated by this receptor. We constructed and expressed a chimeric receptor (Fms-Nyk) composed of the extracellular domain of the human colony-stimulating factor 1 receptor (Fms) and the transmembrane and cytoplasmic domains of human Nyk/Mer in NIH 3T3 fibroblasts in order to investigate the mitogenic signaling and biochemical properties of Nyk/Mer.
Colony-stimulating factor
1 stimulation of the Fms-Nyk chimeric receptor in transfected NIH 3T3 fibroblasts leads to a transformed phenotype and generates a proliferative response in the absence of other growth factors. We show that phospholipase C gamma, phosphatidylinositol 3-kinase/p70 S6 kinase, Shc, Grb2, Raf-1, and
mitogen-activated protein kinase
are downstream components of the Nyk/Mer signal transduction pathways. In addition, Nyk/Mer weakly activates p90rsk, while
stress-activated protein kinase
, Ras GTPase-activating protein (GAP), and GAP-associated p62 and p190 proteins are not activated or tyrosine phosphorylated by Nyk/Mer. An analysis comparing the Nyk/Mer signal cascade with that of the epidermal growth factor receptor indicates substrate preferences by these two receptors. Our results provide a detailed description of the Nyk/Mer signaling pathways. Given the structural similarity between the Ufo/Axl family receptors, some of the information may also be applied to other members of this receptor tyrosine kinase family.
...
PMID:Mitogenic signals and transforming potential of Nyk, a newly identified neural cell adhesion molecule-related receptor tyrosine kinase. 852 23
MAP kinase
(
MAPK
) and its activator, MAP kinase kinase (MAPKK), are commonly activated by a variety of extracellular stimuli in mammalian cells and in the process of Xenopus oocyte maturation. In order to investigate the function of the
MAPK
cascade in oocyte maturation, we produced an anti-Xenopus MAPKK which specifically reacts with MAPKK in vitro. When this antibody was microinjected into immature oocytes,
MAPK
activation induced by progesterone was prevented. Surprisingly, H1 kinase activation and germinal vesicle breakdown were also inhibited in the oocytes injected with this antibody. These results suggest that the
MAPK
cascade plays an important role in the maturation promoting factor (MPF) activation during the oocyte maturation process. When this antibody together with Mos was microinjected into Xenopus two-cell embryos, the Mos-induced metaphase arrest (
CSF
arrest) was prevented. Thus, the
MAPK
cascade may mediate
CSF
arrest. During Xenopus early embryogenesis, a low but significant level of
MAPK
remains active. Injection of mRNA encoding a constitutively active MAPKK resulted in mesoderm induction in animal cap explants. In addition, fibroblast growth-factor (FGF)-induced mesoderm induction was inhibited by expressing CL100 (a
MAP kinase
phosphatase) in animal cap explants. Thus the
MAPK
cascade may be involved in the mesoderm induction of Xenopus embryos. The activation pathways and roles of the MAPKK/
MAPK
cascade in various signaling processes will be discussed.
...
PMID:Activation mechanism and function of the MAP kinase cascade. 860 80
The newly defined eicosatetraenoates (ETEs), 5-oxoETE and 5-oxo-15(OH)-ETE, share structural motifs, synthetic origins, and bioactions with leukotriene B4 (LTB4). All three eicosanoids stimulate Ca2+ transients and chemotaxis in human neutrophils (PMN). However, unlike LTB4, 5-oxoETE and 5-oxo-15(OH)-ETE alone cause little degranulation and no superoxide anion production. However, we show herein that, in PMN pretreated with granulocyte-macrophage or granulocyte colony-stimulating factor (
GM-CSF
or G-CSF), the oxoETEs become potent activators of the last responses. The oxoETEs also induce translocation of secretory vesicles from the cytosol to the plasmalemma, an effect not requiring cytokine priming. To study the mechanism of PMN activation in response to the eicosanoids, we examined the activation of
mitogen-activated protein kinase
(
MAPK
) and cytosolic phospholipase A2 (cPLA2). PMN expressed three proteins (40, 42, and 44 kDa) that reacted with anti-
MAPK
antibodies. The oxoETEs, LTB4,
GM-CSF
, and G-CSF all stimulated PMN to activate the MAPKs and cPLA2, as defined by shifts in these proteins' electrophoretic mobility and tyrosine phosphorylation of the MAPKs. However, the speed and duration of the
MAPK
response varied markedly depending on the stimulus. 5-OxoETE caused a very rapid and transient activation of
MAPK
. In contrast, the response to the cytokines was rather slow and persistent. PMN pretreated with
GM-CSF
demonstrated a dramatic increase in the extent of
MAPK
tyrosine phosphorylation and electrophoretic mobility shift in response to 5-oxoETE. Similarly, 5-oxoETE induced PMN to release some preincorporated [14C]arachidonic acid, while
GM-CSF
greatly enhanced the extent of this release. Thus, the synergism exhibited by these agents is prominent at the level of
MAPK
stimulation and phospholipid deacylation. Pertussis toxin, but not Ca2+ depletion, inhibited
MAPK
responses to 5-oxoETE and LTB4, indicating that responses to both agents are coupled through G proteins but not dependent upon Ca2+ transients. 15-OxoETE and 15(OH)-ETE were inactive while 5-oxo-15(OH)-ETE and 5(OH)-ETE had 3- and 10-fold less potency than 5-oxoETE, indicating a rather strict structural specificity for the 5-keto group. LY 255283, a LTB4 antagonist, blocked the responses to LTB4 but not to 5-oxoETE. Therefore, the oxoETEs do not appear to operate through the LTB4 receptor. In summary, the oxoETEs are potent activators of PMN that share some but not all activities with LTB4. The response to the oxoETEs is greatly enhanced by pretreatment with cytokines, indicating that combinations of these mediators may be very important in the pathogenesis of inflammation.
...
PMID:5-Oxo-eicosanoids and hematopoietic cytokines cooperate in stimulating neutrophil function and the mitogen-activated protein kinase pathway. 866 32
5-Oxo-eicosatetraenoate (5-oxoETE) is gaining recognition as a chemotactic factor for eosinophilic (Eo) as well as neutrophilic (Neu) polymorphonuclear leukocytes. We found that the eicosanoid was far stronger than C5a, platelet-activating factor (PAF), leukotriene B4 (LTB4), or FMLP in stimulating Eo chemotaxis. Moreover, it had weak intrinsic degranulating effects on otherwise unstimulated Eo, produced prominent degranulation responses in Eo primed by granulocyte-macrophage
CSF
, and enhanced the Eo-degranulating potencies of PAF, C5a, LTB4, and FMLP by up to 10,000-fold. Low picomolar levels of 5-oxoETE also induced Eo to activate mitogen-activated protein kinases (MAPKs), as defined by shifts in the electrophoretic mobility and tyrosine phosphorylation of two immunodetectable proteins, p44 and p42. 5-OxoETE was > or = 100-fold weaker or unable to stimulate any of these responses in Neu. Finally, 5-oxo-15-hydroxy-ETE and 5-hydroxy-ETE activated both cell types, but were weaker than 5-oxoETE and had Eo/Neu potency ratios approaching unity. 5-OxoETE, thus, is uniquely potent and selective in promoting Eo not only to migrate, but also to release granule enzymes and activate MAPKs. By triggering
MAPK
activation, the eicosanoid may also influence the production of anaphylactoid lipids (e.g., PAF), arachidonic acid metabolites, and cytokines. 5-OxoETE therefore possesses a biologic profile well suited for mediating Eo-dominated allergic reactions in vivo.
...
PMID:5-Oxo-eicosatetraenoate is a broadly active, eosinophil-selective stimulus for human granulocytes. 868 35
Stimulation of T cells via the T cell receptor (TCR) activates a number of signaling pathways that are potentially involved in the elicitation of physiological responses, such as the production of cytokines. The extracellular signal-regulated kinases (ERK) are a group of molecules activated in response to TCR ligation, whose role in T cell cytokine production is controversial. In this study, we have asked whether ERK activation is coupled to the production of a number of T cell-derived cytokines, and whether particular cytokines are differentially affected by ERK activation. To address these questions, we have utilized a constitutively active version of the immediate upstream activator of both
ERK1
and
ERK2
, mitogen-activated/extracellular signal-regulated kinase 1 (MEK1), to activate ERK signaling selectively in the absence of other TCR-activated signaling pathways. The effect of constitutive MEK/ERK activation on T cell cytokine production was measured by transiently co-transfecting newly activated mouse T cells with DNA encoding constitutively active MEK1 (CA-MEK1) and the human interleukin-2 (IL-2) receptor alpha chain (hCD25), purifying hCD25+ transfectants by flow-cytometric cell sorting, and measuring the production of IL-3, IL-4, interferon (IFN)-gamma and granulocyte/macrophage-colony-stimulating factor (GM-CSF) either in the presence or absence of ionomycin stimulation. Newly activated T cells were used in these experiments as they more closely resemble T cells activated in vivo than do transformed T cells or long-term established T cell clones. CA-MEK1 expression led to constitutive ERK activation, which acted synergystically with ionomycin treatment to stimulate cytokine production. Furthermore, these experiments revealed a hierarchy of cytokine responsiveness to MEK/ERK activation, such that the production of IL-3 was most affected, followed by GM-
CSF
, IFN-gamma, and IL-4.
...
PMID:Differential activation of T cell cytokine production by the extracellular signal-regulated kinase (ERK) signaling pathway. 889 34
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