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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Ligation of Ag receptors in T and B lymphocytes initiates signal transduction cascades which alter the expression of genes that regulate cellular proliferation and differentiation. The transmission of signals from the membrane to the nucleus is mediated principally through the action of protein tyrosine and serine/threonine kinases. We have identified and characterized a novel serine/threonine kinase that phosphorylated the proto-oncogene product, c-Fos, and is termed Fos kinase. Fos kinase was rapidly activated after ligation of the CD3 and CD2 receptors in Jurkat and normal human T lymphocytes and in response to
IL-6
and anti-IgM in the human B cell lines AF10 and Ramos, respectively. The phorbol ester, PMA, was also a potent inducer of Fos kinase activity in all of the above populations, suggesting that PKC plays a role in the regulation of this enzyme. Fos kinase phosphorylates c-Fos at a site near the C-terminus, as well as a peptide derived from this region (residues 359-370, RKGSSSNEPSSD), and Fos peptide competitively inhibited c-Fos phosphorylation. Fos kinase was shown to be distinct from other identified serine/threonine kinases, including
protein kinase A
, protein kinase C,
casein kinase II
, MAP kinases, p70S6K and p90RSK. Fos kinase was purified by anion exchange chromatography and exhibited an apparent M(r) = 65,000 and isoelectric point = 6.1. Fos kinase may play a role in transcriptional regulation through its capacity to phosphorylate c-Fos at a site required for expression of the transcriptional transrepressive activity of this molecule. Moreover, its rapid activation suggests it may have a wider role within signal transduction cascades in lymphocytes.
...
PMID:Activation of a novel serine/threonine kinase that phosphorylates c-Fos upon stimulation of T and B lymphocytes via antigen and cytokine receptors. 815 58
Using the human monocytic cell line Mono Mac 6 we studied the involvement of Ca2+,
protein kinase A
(
PKA
), and protein kinase C (PKC) dependent pathways in the regulation of M-CSF and
IL-6
gene expression. The results demonstrate that on activation with the calcium ionophore A23187 both M-CSF and
IL-6
mRNA are induced after 3 and 6 h respectively. Co-stimulation with A23187 plus PMA resulted in an up-regulation of M-CSF mRNA and a down-regulation of
IL-6
mRNA. Conversely co-stimulation with A23187 plus DBcAMP resulted in a down-regulation of M-CSF mRNA and an up-regulation of
IL-6
mRNA. Nuclear run-on and mRNA half-life studies showed that the effects on the M-CSF expression were related to changes at transcriptional and post-transcriptional level. In contrast, the effects on the
IL-6
gene expression seems to be mediated at post-transcriptional level. With regard to the secretion of the
IL-6
protein it was shown that it closely follows the accumulation of
IL-6
mRNA. Taken together, the data show that several intracellular signalling pathways control strictly the cytokine expression in monocytic cells which gives the cells the opportunity to respond variably to external activation signals.
...
PMID:Differential regulation of M-CSF and IL-6 gene expression in monocytic cells. 819 14
Bacterial LPS induce production of cytokines such as IL-1,
IL-6
, and TNF in mononuclear phagocytes, and this represents a central component in the pathogenesis of septic shock syndrome. However, the mechanisms by which LPS activates these cells to express cytokines are not completely characterized. The present study addressed the role of different protein kinases in the LPS induction of cytokines. It is shown that LPS induced a 12- to 16-fold increase in IL-1 beta,
IL-6
, and TNF-alpha mRNA levels, and this was completely or more than 80% blocked by the protein tyrosine kinase specific inhibitors herbimycin A and genistein at the concentrations of 1.7 and 37 microM, respectively. Protein kinase C inhibition by staurosporine reduced LPS induction of TNF-alpha, whereas it had no effects on
IL-6
and IL-1 beta. Inhibition of
protein kinase A
by H89 reduced
IL-6
mRNA levels but did not detectably change IL-1 beta or TNF-alpha mRNA levels. In contrast, LPS did not increase leukemia inhibitory factor mRNA, which was constitutively expressed and not significantly reduced by these inhibitors. In addition to cytokine mRNA levels, LPS-induced
IL-6
protein synthesis and
IL-6
bioactivity were also reduced to baseline levels by the PTK inhibitors herbimycin A and genistein. Both PTK inhibitors also reduced the LPS activation of nuclear factor-kappa B (NF-kappa B), which is a transcription factor involved in the expression of cytokine genes such as
IL-6
and TNF-alpha. The activation of NF-kappa B was also reduced by H89, whereas staurosporine had no effect on this response. In summary, these findings suggest that protein kinase C and
protein kinase A
appear to have selective effects in the LPS induction of cytokines, whereas PTK is required for LPS induction of a broad spectrum of cytokines and NF-kappa B activation in monocytes.
...
PMID:Protein tyrosine kinase activation is required for lipopolysaccharide induction of cytokines in human blood monocytes. 825 85
After the binding of IL-2, IL-4, or
IL-6
to their respective receptors on activated human B cells, a multistep cascade of intracellular events is initiated that results in the secretion of Ig. However, it is not known whether these different cytokine receptors use common or divergent signal transduction pathways to stimulate Ig secretion. Therefore, we examined the signaling mechanisms used by a human lymphoblastoid cell line arrested at a late stage of differentiation, SKW6.4, that secretes IgM following stimulation with IL-2, IL-4, or
IL-6
alone. Our study demonstrated that IL-2, IL-4, and
IL-6
-stimulation of IgM secretion by SKW6.4 cells was inhibited by either the serine/threonine kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperizine dihydrochloride (H7) or the tyrosine kinase inhibitor, genistein. To investigate the early phosphorylation events initiated by these cytokines, a membrane-enriched preparation from SKW6.4 cells was isolated in a manner that minimized the disruption of membrane protein complexes and then incubated with IL-2, IL-4, or
IL-6
in the presence of [gamma-32P]ATP. IL-2, IL-4, and
IL-6
stimulated the rapid serine/threonine phosphorylation of 47-, 49-, and 91-kDa proteins. However, in contrast to the 47- and 49-kDa proteins that remained phosphorylated for up to 30 min poststimulation, the 91-kDa protein was rapidly dephosphorylated within 15 min of stimulation. The observation that serine/threonine phosphorylation of the same proteins was stimulated by IL-2, IL-4, and
IL-6
suggested that the cytokines activated either different protein kinases with the same substrate specificity or the same
protein kinase
. In addition, stimulation of intact SKW6.4 cells with either IL-2, IL-4, or
IL-6
induced the phosphorylation of two proteins with molecular masses of 45- to 50-kDa and 85 to 90-kDa. Taken together, our data demonstrate that activation of both a serine/threonine kinase and a tyrosine kinase is involved in the IL-2, IL-4, and
IL-6
-stimulation of IgM secretion by SKW6.4 cells and activation of the same or a similar
serine/threonine protein kinase
is an early step in the signal transduction pathway used by these cytokines.
...
PMID:Immunoglobulin secretion and phosphorylation of common proteins are induced by IL-2, IL-4, and IL-6 in the factor responsive human B cell line, SKW6.4. 825 86
It is believed that induction of cytokine expression by bacterial cell wall components plays a role in the development and course of sepsis. However, most attention has been focused on lipopolysaccharide (LPS). We studied the ability of N-acetylglucosaminyl-1,6-anhydro-N-acetylmuramyl-L-alanyl-D- isoglutamyl-m-diaminopimelyl-D-alanine (G(Anh)MTetra), a naturally occurring breakdown product of peptidoglycan that is produced by soluble lytic transglycosylase of Escherichia coli, to induce cytokine expression in human monocytes. G(Anh)MTetra was found to strongly induce interleukin (IL)-1 beta and
IL-6
mRNA expression after 2 h and IL-1 beta and
IL-6
protein secretion after 48 h of activation. The increase in mRNA accumulation was at least partly due to an increase in the transcription rates of the respective genes and was accompanied by a strong induction of nuclear factor-kappa B and activator protein-1 transcription factor expression. Experiments using inhibitors of protein kinase C,
protein kinase A
, and tyrosine kinase-dependent pathways revealed that G(Anh)MTetra-induced IL-1 beta and
IL-6
mRNA expression involves activation of an H7-inhibitable pathway. By using the protein synthesis inhibitor cycloheximide, it was shown that G(Anh)MTetra-induced
IL-6
mRNA expression depends on the synthesis of new protein, whereas G(Anh)MTetra-induced IL-1 beta mRNA accumulation does not. When responses to G(Anh)MTetra were compared with those to LPS and muramyldipeptide (MDP), it was found that the optimal response to G(Anh)MTetra induction was similar to that of LPS but significantly higher than the response to MDP. Furthermore, maximal G(Anh)MTetra-induced IL-1 beta and
IL-6
mRNA expression could be enhanced by co-stimulation with LPS or MDP, suggesting that different receptors and/or transduction pathways were involved. These results indicate that G(Anh)MTetra induces IL-1 beta and
IL-6
expression in human monocytes suggesting a possible role for G(Anh)MTetra in the release of cytokines during sepsis.
...
PMID:G(Anh)MTetra, a natural bacterial cell wall breakdown product, induces interleukin-1 beta and interleukin-6 expression in human monocytes. A study of the molecular mechanisms involved in inflammatory cytokine expression. 830 82
We studied the effects of interleukin-6(
IL-6
) on DNA synthesis and cyclic AMP production in rat thyroid FRTL-5 cells. When cells were incubated with
IL-6
in the presence or absence of IGF-I, cell proliferation was not observed. By contrast,
IL-6
stimulated DNA synthesis in a dose dependent manner when TSH was added concomitantly. On the other hand,
IL-6
did not modulate the cAMP accumulation in the presence or absence of TSH. These data demonstrate that, like IGF-I,
IL-6
may be able to act as a growth factor through activation of a mitogenic signal transduction pathway different from
A-kinase
in FRTL-5 cells.
...
PMID:Effect of interleukin-6 on cell proliferation of FRTL-5 cells. 838 10
Interleukin (IL) 11 is a multifunctional cytokine derived from bone marrow stromal cells. To understand the mechanisms by which IL-11 exerts its pleiotropic actions, we have analyzed IL-11-mediated signal transduction pathways in IL-11-dependent B9-TY1, which is a subclone of an
IL-6
-dependent B-cell hybridoma, B9. IL-11 stimulation of B9-TY1 cells resulted in tyrosine phosphorylation of a 97/95 kilodalton cellular protein in a dose-dependent manner, and this effect was inhibited by tyrosine kinase inhibitors genistein and herbimycin A, but not by a serine/threonine kinase inhibitor, H7. We next examined the early nuclear events in the IL-11-triggered intracellular signaling cascade. The data showed that tis11, tis21, and junB early response genes were rapidly activated following IL-11 treatment. The kinetic studies indicated that activation of tis11 and junB genes peaked at 30-60 min and then declined slowly afterward. The tis21 gene was constitutively expressed, and the level of tis21 mRNA was significantly increased and maintained at the elevated level following IL-11 stimulation. Inhibitor studies with genistein, herbimycin A, and H7 revealed that tyrosine kinases and H7-sensitive serine/threonine kinases are required for the IL-11-mediated activation of tis11, tis21, and junB genes. Using a variety of known
protein kinase
inhibitors or activators, we have demonstrated that H7-sensitive protein kinases activated by IL-11 are distinct from those of well-characterized
protein kinase
-second messenger systems.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Protein tyrosine phosphorylation and activation of primary response genes by interleukin 11 in B9-TY1 cells. 839 1
IFN-alpha influences the recirculation and growth of normal and malignant B lymphocytes, although the mechanisms involved are not currently known. Lymphocyte recirculation is fundamentally dependent on cell-to-cell interactions that are mediated by cell surface adhesion molecules. In this report, we examined the relationship between the effect of IFN-alpha on cell-to-cell adhesion processes and induction of the Leu-13 cell surface protein in established human Daudi B lymphoid cell lines that are either sensitive or resistant to the antiproliferative activity of IFN-alpha. IFN-alpha directly triggered homotypic adhesion of IFN-sensitive Daudi B cells in a time- and dose-dependent manner. In contrast, IFN-alpha had no effect on the cell-to-cell adhesion of IFN-resistant Daudi B cells. The capacity of IFN-alpha to trigger homotypic aggregation correlated directly with the level of induction of the cell surface protein Leu-13 and could be potentiated by anti-Leu-13 mAb. Other cytokines also known to influence the proliferation, differentiation, or recirculation of B lymphocytes such as IFN-gamma, IL-2, IL-4,
IL-6
, TNF-alpha, and low molecular weight B cell growth factor did not induce either Leu-13 expression or homotypic aggregation of Daudi B cells. The adhesion pathway triggered by the IFN-inducible protein Leu-13 required metabolic energy and an intact cytoskeleton but was not dependent on: 1) new protein synthesis; 2) protein kinase C,
protein kinase A
, or tyrosine kinase activities; or 3) the function of known adhesion molecules including LFA-1, ICAM-1, CD44, or VLA-4. Taken together, these studies demonstrate a fundamental role for IFN-alpha and the IFN-inducible protein Leu-13 in regulating a novel homotypic adhesion pathway in B lymphocytes, and provide insight into the possible mechanisms by which IFN-alpha regulates biologic processes including recirculation.
...
PMID:IFN-alpha induces homotypic adhesion and Leu-13 expression in human B lymphoid cells. 842 37
Human monocyte-derived macrophages (M phi) from the majority of normal donors respond to inoculation with Mycobacterium avium, serotype 4, (MAI) by elaboration of the inflammatory monokines TNF-alpha, IL-1 beta, and
IL-6
, which are of central importance for the protection against bacterial and parasitic infections. Peak TNF-alpha mRNA levels were of brief duration, being maximal at 1.5 h, and were only slightly higher than background levels at 4 h. Increases of IL-1 beta and
IL-6
mRNA levels, on the other hand, persisted for 48 to 72 h. In contrast to LPS, MAI induced the production of only small amounts of TNF-alpha protein in the first 12 h and of large amounts of IL-1 beta and
IL-6
protein between 3 and 72 h. MAI-induced TNF-alpha transcripts, in contrast to LPS induced TNF-alpha transcripts, were highly unstable. Their accumulation was blocked and their t 1/2 significantly decreased by the protein kinase C inhibitor staurosporine. In contrast, LPS-induced increases of TNF-alpha mRNA levels and MAI-induced increases of IL-1 beta and
IL-6
mRNA levels were PKC independent. The cAMP- and
cGMP-dependent protein kinase
inhibitors, KT5720 and KT5823, respectively, and the tyrosine kinase inhibitors herbimycin and erbstatin had no effect on the MAI-dependent mRNA accumulation of TNF-alpha, IL-1 beta, and
IL-6
. W7, a calmodulin-dependent protein kinase inhibitor, was inhibitory in all cases. Thus, MAI-induced TNF-alpha mRNA accumulation is of short duration and PKC dependent. MAI-induced TNF-alpha protein production is low, possibly resulting in a mitigated antimicrobial effect.
...
PMID:TNF-alpha response of human monocyte-derived macrophages to Mycobacterium avium, serovar 4, is of brief duration and protein kinase C dependent. 845 62
Bone-resorbing osteoclasts are of hemopoietic cell origin, probably of the CFU-M-derived monocyte-macrophage family. Bone marrow-derived osteoblastic stromal cells play an important role in modulating the differentiation of osteoclast progenitors in two different ways: one is the production of soluble factors, and the other is cell-to-cell recognition between osteoclast progenitors and osteoblastic stromal cells. M-CSF is probably the most important soluble factor, which appears to be necessary for not only proliferation of osteoclast progenitors, but also differentiation into mature osteoclasts and their survival. A number of local factors as well as systemic hormones induce osteoclast differentiation. They are classified into three categories in terms of the signal transduction: vitamin D receptor-mediated signals [1 alpha,25(OH)2D3];
protein kinase A
-mediated signals (PTH, PTHrP, PGE2, and IL-1); and gp130-mediated signals (
IL-6
, IL-11, oncostatin M, and leukemia inhibitory factor). All of these osteoclast-inducing factors appear to act on osteoblastic cells to commonly induce osteoclast differentiation factor (ODF), which recognizes osteoclast progenitors and prepares them to differentiate into mature osteoclasts. This line of approach will undoubtedly produce new ways to treat several metabolic bone diseases caused by abnormal osteoclast recruitment such as osteoporosis, osteopetrosis, Paget's disease, rheumatoid arthritis, and periodontal disease.
...
PMID:Modulation of osteoclast differentiation by local factors. 857 4
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