Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.13 (protein kinase C)
 49,245 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuous proliferation of the immortalized myeloid progenitor cell line FDC-P1 depends on stimulation with either interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF). Two other cytokines, interferon-gamma (IFN-gamma) and IL-4, were found to prolong FDC-P1 survival for several days. Surviving cells incorporated [3H]thymidine and a minority completed up to 3 cell divisions before dying. This transient proliferative response was a direct effect of IFN-gamma and IL-4 since these cytokines did not induce production of detectable IL-3 or GM-CSF and the response was unaffected by cell concentration. IL-6, a constitutive product of FDC-P1 cells whose secretion was increased by IL-3, GM-CSF and IL-4 but not by IFN-gamma, was not responsible for the proliferative response. FDC-P1 lines that constitutively expressed the cell cycle-associated oncogene myc or the survival-associated oncogene bcl-2 also responded only transiently to IFN-gamma or IL-4, indicating that expression of these genes did not complement the signals delivered by IFN-gamma or IL-4. By contrast, the protein kinase C activator phorbol 12-myristate 13-acetate (PMA) prolonged survival of FDC-P1 cells on its own and potentiated the response to IFN-gamma or IL-4, although the combination of stimuli did not support long-term growth. It is concluded that IFN-gamma and IL-4 trigger only some of the signalling events that lead to mitogenesis; these events are complemented by stimulation with PMA but additional signals are required for sustained proliferation.
 ...
PMID:Survival of the myeloid progenitor cell line FDC-P1 is prolonged by interferon-gamma or interleukin-4. 138 29

We have previously reported transformation to growth factor-independent proliferation in the interleukin-3 (IL-3)-dependent cell line FDC-P1 by high-level expression of the valine 12 Harvey RAS oncogene, following from a nonautocrine mechanism. The present study was undertaken to examine nuclear tertiary messenger, transcriptional response gene expression to deduce the intracellular signaling pathways responsible for this autonomous proliferation. We confirmed other reports that transformed p21RAS-expressing cells constitutively express the transcription factor complex jun/AP-1, in this case resulting from the ongoing expression of the c-jun and c-fos genes in the absence of IL-3. However, the ongoing growth factor independent expression of c-myc by a transcriptional mechanism in FDC-P1 cells expressing p21 RAS cannot be explained by intracellular signaling in the jun/AP-1 (protein kinase C) pathway. This conclusion derives from the observation that c-jun expression mediated via protein kinase C activation with phorbol ester (12-0-tetra decanoylphorbol-13-acetate, TPA) treatment does not lead to c-myc expression in parent FDC-P1 cells. On the contrary, FDC-P1 cells stably transfected with a c-myc gene controlled under the influence of a metallothionein IIA promoter (containing the TPA-responsive element [TRE]) express the transfected MTIIA-c-myc and downregulate the endogenous c-myc in response to protein kinase C activation with TPA. Further, nuclear proteins derived from cells expressing p21 RAS, which bind specifically to the purified c-myc P2 promoter, are not competed in their binding to the motif-rich P2 element by AP-1 oligonucleotide. Therefore, expression of the Harvey RAS oncogene in FDC-P1 myeloid cells leads to at least two pathways of cytoplasmic signaling. One pathway involves protein kinase C and c-jun/AP-1, but another pathway that is protein kinase C-independent appears to mediate c-myc transcription.
 ...
PMID:Dissociation of nuclear events on p21 RAS transformation of FDC-P1 myeloid cells: c-jun/AP-1 expression versus c-myc transcription. 157 52

The myeloid interleukin-3 (IL-3) dependent cell line, FDC-P1, enters the G0 stage of the cell cycle after IL-3 deprivation for 24 hr. The expression of 13 protooncogenes and immediate-early genes was compared with 4 "control" genes after the addition of either IL-3 or phorbol myristate acetate (PMA) to IL-3-deprived cells. mRNA transcripts encoding c-myc and the T-cell receptor c-gamma gene were induced to high levels only after IL-3 addition, whereas c-fos, fos-B, c-jun, jun-B, Krox-20, and Krox-24 were induced transiently only after PMA addition. The remaining genes (fra-1, p53, jun-D, c-Ha-ras, c-Ki-ras, c-raf, beta-actin, ornithine decarboxylase, and histone 2B) were detected after culture with either IL-3 or PMA. When cells were serum- and IL-3-deprived, c-fos, fos-B, c-jun, jun-B, Krox-20, and Krox-24 were detected after exposure to either serum or PMA. Moreover, culture with cycloheximide and PMA resulted in superinduction of these genes, whereas cycloheximide and IL-3 addition did not. mRNAs encoding these genes had half-lives of 10-20 min after PMA treatment, whereas that of beta-actin was longer (greater than 2 hr), suggesting that short mRNA half-lives contributed to the transient nature of these genes. Although c-fos, fos-B, c-jun, jun-B, Krox-20, and Krox-24 expression can be detected in IL-3-dependent cells after exposure to either PMA or serum, these genes were not detected after IL-3 addition, which allows cell-cycle progression. These results document the existence of IL-3 and PMA-responsive genes and demonstrate that IL-3 and protein kinase C agonists can induce distinct patterns of gene expression.
 ...
PMID:Interleukin-3 and phorbol esters induce different patterns of immediate-early gene expression in an interleukin-3 dependent cell line. 170 18

The signaling pathways used by interleukin-3 (IL-3) and by active phorbol ester (12-0-tetradecanoyl phorbol-13-acetate, TPA) to stimulate mitogenesis in the growth factor dependent myeloid cell line FDC-P1 were studied by 'reporter' analysis of nuclear proto-oncogene expression. These studies revealed that IL-3 strongly stimulated c-myc expression by a transcriptional mechanism but IL-3 poorly stimulated c-jun expression, a measure of protein kinase C dependent signals. On the other hand, the protein kinase C agonist, TPA, strongly activated c-jun expression but poorly promoted expression (transcription) of c-myc in FDC-P1. These findings appeared to correlate with the poor mitogenic capacity of TPA for FDC-P1. However, stable transfection of FDC-P1 with a c-myc expression vector driven by a human methallothionein IIA promoter containing the TPA responsive element (TRE), led to a cell clone, FDMT myc.A1, in which TPA mediated selective transcription of the transfected TRE driven c-myc vector and down-regulated expression of the endogenous c-myc gene. IL-3 selectively failed to stimulate expression of the TRE driven c-myc vector in FDMT myc.A1. Augmented TPA dependent vector derived c-myc expression was accompanied by enhanced mitogenesis of the cell line FDMT myc.A1 compared with FDC-P1. In addition, TPA mediated expression of the transfected c-myc gene in FDMT myc.A1 was accompanied by augmented transcription of c-jun and c-fos in response to TPA. These studies show the importance of a non-protein kinase C dependent pathway for IL-3 mediated c-myc transcription. However, these studies reveal that protein kinase C mediated pathways can be promitogenic, especially when complemented by unregulated c-myc expression (in this case driven by an alternative, TRE containing promoter).
 ...
PMID:Interleukin-3 dependent mitogenesis in murine cells involves a predominant non-protein kinase C (pKC) dependent pathway for c-myc transcription. Role of a myc expression vector in rescuing pKC dependent mitogenesis. 177 59

FD/PMA is a subclone of the interleukin-3 (IL-3)-dependent, FDC-P1 cell line, which proliferates in response to either 12-O-tetradecanoylphorbol-13 acetate (PMA) or IL-3. While several endogenous substrates were phosphorylated in response to protein kinase C (PKC) activation in FDC-P1, phospholipid-dependent phosphorylation in the FD/PMA grown in PMA was not observed. Basal, phosphatidylserine-independent, and diolein-independent phosphorylation of cytosolic substrates with molecular weights of 17, 52, 57, and 105 Kd were enhanced in FD/PMA cells grown in PMA as compared with FDC-P1 cells cultured in IL-3. Phosphorylation of a 105-Kd substrate was enhanced in the particulate fraction of FD/PMA cells maintained in PMA. The 17-Kd substrate in FD/PMA cells comigrated with a substrate phosphorylated in a PKC-dependent manner in FDC-P1 cells. Phosphorylation of the 52- and 57-Kd substrates, but not of the 17-Kd substrate, was inhibited by H-7 and staurosporine. A portion of the PMA-induced cytosolic kinase activity coeluted with PKC on diethyl aminoethyl chromatography. While FD/PMA cells cultured in PMA contained negligible PKC-dependent phosphorylation of endogenous substrates or histone, alpha and epsilon PKC isoforms were detected by Western blot analysis. PKC phosphotransferase activity was observed in FD/PMA cells grown in PMA when peptides corresponding to residues 720 to 737 of PKC-epsilon or residues 4 to 14 of myelin basic protein were used as substrates. These data indicate that maintenance of FD/PMA cells in PMA stimulates proliferation and markedly alters PKC substrate specificity. Generation of at least two phospholipid-independent kinases occurs in PMA-treated cells.
 ...
PMID:Differential effect of phorbol esters and interleukin-3 on protein kinase C isoform content and kinase activity in the FDC-P1 cell line. 182 57

The factor-dependent cell line FDC-P1 has been utilized as a model of interleukin 3 (IL-3)-dependent myeloid cell proliferation. However, it has been recently observed that active phorbol esters (e.g., phorbol 12-myristate 13-acetate) may entirely replace IL-3 to promote its proliferation. These observations reveal abnormal regulation of protein kinase C (pkC) (absence of downregulation or overexpression). This property allowed a test of the hypothesis that the T24 RAS (codon 12) oncogene acts by constitutive and persistent pkC activation, driving proliferation. FDC-P1 cells were transfected by electroporation with the T24 RAS-containing vector pAL 8, or with a control vector pSVX Zip Neo, and neomycin-resistant clones were selected. Multiple RAS-transfectant clones were categorized for their growth factor requirement and incorporation of the 6.6-kb human mutant H-RAS genome. IL-3-independent clones had incorporated multiple (more than two) copies of the entire 6.6-kb RAS genome. The incorporation of multiple 6.6-kb RAS genomes was correlated with high-level p21 RAS expression. No evidence for autostimulatory growth factor production by clones containing the RAS oncogene was observed. Thus, acquisition of growth factor independence in myeloid cells by abundant expression of a RAS oncogene is linked, in part, to abnormal regulation of pkC, which acts as a collaborating oncogene.
 ...
PMID:A RAS oncogene imparts growth factor independence to myeloid cells that abnormally regulate protein kinase C: a nonautocrine transformation pathway. 218 24

A role for second messenger-regulated protein kinases in the early post-IL-3 receptor signal transduction pathway was investigated in the mast cell/megakaryocyte line R6-XE.4. The activity of the calcium- and phospholipid-dependent protein kinase C (PKC) was assessed by the ability of the enzyme to phosphorylate histone H1 in the presence of calcium, diacylglycerol, and phosphatidylserine or after proteolytic activation of PKC with trypsin. In high serum-supplemented cells, but not in cells that were preincubated in serum-deficient media for 6 h, subsequent treatment for 15 min with synthetic IL-3 (10 micrograms/ml) caused up to a sixfold increase in the calcium- and lipid-stimulated histone H1 phosphorylating activity of particulate-associated PKC after fractionation on MonoQ. However, there was no corresponding reduction of cytosolic PKC activity. Therefore, IL-3 appeared to modify the activity of preexisting membrane-associated PKC rather than eliciting its recruitment from the cytoplasm in R6-XE.4 cells. This was in contrast to the situation with FDC-P1 cells, where IL-3 induced PKC translocation. IL-3 also stimulated a cytosolic protein kinase that phosphorylated a synthetic peptide patterned after a phosphorylation site in ribosomal protein S6, but this IL did not alter the activity of cAMP-dependent protein kinase.
 ...
PMID:IL-3-induced activation of protein kinases in the mast cell/megakaryocyte R6-XE.4 line. 230 40

FDC-P1 is an interleukin-3 (IL-3)-dependent cell line that ceases to proliferate in the absence of IL-3. We have isolated variant cell lines from FDC-P1 that grow in response to phorbol myristate acetate (PMA). These variant cell lines (FD/PMA) have maintained their PMA-dependency for over 1 year. Lymphokine gene expression, which would support growth, was not detected in FD/PMA lines. FD/PMA lines had a different cell surface phenotype than the parental line. Mac-1, Mac-2, and Mac-3 were readily detected on the cell surface of FD/PMA lines; however, these antigens were not detected on FDC-P1. Because protein kinase C (PKC) activation may mediate PMA effects, we examined this kinase. PKC activity quantitated by 32P-incorporation into histone was increased in FDC-P1 as compared with FD/PMA cultured in IL-3. Moreover, PKC activity was undetectable in FD/PMA lines cultured in PMA. Using Western blotting, immunoreactive PKC was readily detected in cytosolic and solubilized particulate fractions of FDC-P1 cells, not but in FD/PMA cell extracts. Comparisons between the parental and FD/PMA lines should provide insight into IL-3- and PMA-mediated signal transduction.
 ...
PMID:Effects of phorbol esters on an interleukin-3-dependent cell line. 236 74

To examine whether overexpression of protein kinase C (PKC) is sufficient to allow for factor-independent growth in hematopoietic cells, we used a recombinant retroviral expression vector system to introduce a cDNA encoding the beta 1 isoform of the PKC gene into IL-3-dependent cells FDC-P1. Cell lines were generated which contained up to 24-fold increases in PKC activity. Analysis of these cell lines demonstrated that PKC activation does not play a significant role in IL-3-mediated growth control, as evidenced by the following: (1) IL-3 addition to either overexpressor cell lines did not induce morphologic changes whereas activators of PKC stimulated cellular clumping; (2) early passage FDC-P1 cells, either carrying normal or elevated levels of PKC, were not stimulated to grow by activators of PKC; and (3) addition of phorbol esters or bryostatin 1 to these cells markedly decreased the levels of PKC without affecting the ability of these cells to grow in IL-3. Therefore, we suggest that IL-3 mediated growth occurs through pathways other than involving PKC.
 ...
PMID:Overexpression of protein kinase C beta 1 is not sufficient to induce factor independence in the interleukin-3-dependent myeloid cell line FDC-P1. 239 26

Interleukin-3 (IL-3) is a lymphokine which stimulates the proliferation of normal and transformed multilineage hematopoietic cells. Recently we reported that bryostatin 1, a macrocyclic lactone and potent activator of protein kinase C, could stimulate normal multipotential hematopoietic progenitor cells in vitro in the absence of added polypeptide growth factors. We have now used the murine IL-3-dependent cell line FDC-P1, derived from normal murine marrow cells, to examine the early biochemical events associated with stimulation of hematopoietic cells. We find that both IL-3 and bryostatin 1 are mitogenic and stimulate the growth of FDC-P1 cells. Cells grown for extended periods in the presence of bryostatin 1 (1 nM) alone retain IL-3 responsiveness, indicating that bryostatin 1 does not induce an IL-3-independent state. Protein phosphorylation studies in cells treated with either IL-3 or bryostatin 1 indicate that both stimulators can mediate the rapid (within 5 min) serine-specific phosphorylation of several nuclear envelope polypeptides, including lamin B. Both IL-3- and bryostatin 1-mediated nuclear envelope phosphorylation is dose-dependent, occurring at concentrations which are mitogenic to FDC-P1 cells. The extent of nuclear envelope phosphorylation mediated by IL-3 and bryostatin 1 correlates with the mitogenic response. Furthermore, both mitogens mediate the rapid immunologic translocation of protein kinase C to the nuclear envelope where phosphorylation occurs. These data indicate that the early mitogenic signal(s) generated by IL-3 and bryostatin 1 may converge at the level of the nuclear envelope, perhaps through a protein kinase C-like activity which mediates phosphorylation of specific nuclear envelope polypeptides such as lamin B.
 ...
PMID:Interleukin-3 and bryostatin 1 mediate rapid nuclear envelope protein phosphorylation in growth factor-dependent FDC-P1 hematopoietic cells. A possible role for nuclear protein kinase C. 260 93


1 2 Next >>