Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.12.2 (MEK)
 18,161 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neurotensin (NT) stimulates protein kinase D1 (PKD1), extracellular signal regulated kinase (ERK), c-Jun N-terminal Kinase (JNK), and DNA synthesis in the human pancreatic adenocarcinoma cell line PANC-1. To determine the effect of PKD1 overexpression on these biological responses, we generated inducible stable PANC-1 clones that express wild-type (WT) or kinase-dead (K618N) forms of PKD1 in response to the ecdysone analog ponasterone-A (PonA). NT potently stimulated c-Jun Ser(63) phosphorylation in both wild type and clonal derivatives of PANC-1 cells. PonA-induced expression of WT, but not K618N PKD1, rapidly blocked NT-mediated c-Jun Ser(63) phosphorylation either at the level of or upstream of MKK4, a dual-specificity kinase that leads to JNK activation. This is the first demonstration that PKD1 suppresses NT-induced JNK/cJun activation in PANC-1 cells. In contrast, PKD1 overexpression markedly increased the duration of NT-induced ERK activation in these cells. The reciprocal influence of PKD1 signaling on pro-mitogenicERK and pro-apopotic JNK/c-Jun pathways prompted us to examine whether PKD1 overexpression promotes DNA synthesis and proliferation of PANC-1 cells. Our results show that PKD1 overexpression increased DNA synthesis and cell numbers of PANC-1 cells cultured in regular dishes or in polyhydroxyethylmethacrylate [Poly-(HEMA)]-coated dishes to eliminate cell adhesion (anchorage-independent growth). Furthermore, PKD1 overexpression markedly enhanced DNA synthesis induced by NT (1-10 nM). These results indicate that PKD1 mediates mitogenic signaling in PANC-1 and suggests that this enzyme could be a novel target for the development of therapeutic drugs that restrict the proliferation of these cells.
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PMID:Induced overexpression of protein kinase D1 stimulates mitogenic signaling in human pancreatic carcinoma PANC-1 cells. 2008 6

The resorcylic acid lactone hypothemycin has been shown to inactivate protein kinases by binding to a cysteine conserved in 46 protein kinases, including mitogen-activated protein kinase kinase (MEK), extracellular signal-regulated kinase (ERK) and platelet-derived growth factor receptor (PDGFR). We assessed the selectivity of hypothemycin in cellular contexts. Hypothemycin normalized the morphology and inhibited anchorage-independent growth of Ki-ras transformed normal rat kidney (NRK) cells with selectivity and potency comparable to or greater than that of the MEK inhibitor U0126. In Ki-ras-transformed and phorbol 12-myristate 13-acetate (PMA)-treated NRK cells, hypothemycin blocked ERK activation but showed a minimal effect on autophosphorylation of protein kinase D1 (PKD1), another kinase containing the conserved cysteine. Hypothemycin potently inhibited PDGFR autophosphorylation and activation of the MEK-ERK pathway in platelet-derived growth factor (PDGF)-treated NRK cells. However, the phosphoinositide-3-kinase (PI3K) pathway was only modestly attenuated. Hypothemycin also inhibited growth factor- and anchorage-independent growth of human cancer cell lines with a constitutively active MEK-ERK pathway. Although hypothemycin has the potential to inactivate various protein kinases, the results indicate that in intracellular environments, hypothemycin can inhibit the MEK-ERK axis with sufficient selectivity to normalize transformed phenotypes of cells dependent on this pathway.
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PMID:The resorcylic acid lactone hypothemycin selectively inhibits the mitogen-activated protein kinase kinase-extracellular signal-regulated kinase pathway in cells. 2011 35

Histone acetylation/deacetylation is a key mechanism for regulating transcription, which plays an important role in the control of gene expression, tissue growth, and development. In particular, histone deacetylase 7 (HDAC7), a member of class IIa HDACs, is crucial in maintaining vascular integrity. Endothelial progenitor cells (EPCs) play an important role in angiogenesis. However, whether HDAC7 plays a role in the processes of EPCs angiogenesis remains unclear. Migration and tube formation were the two major components of EPC angiogenesis. In this study, we show for the first time that HDAC7 silencing weakened the migration and tube formation abilities of EPCs. VEGF-A induced an increase of phospho-HDAC7 and its nuclear export in a time-dependent manner, which could be partly inhibited by protein kinase D1 (PKD1) inhibitor, but not by the PI3K inhibitor or the MEK inhibitor. Our results showed that EPCs involved in the angiogenesis might be controlled by VEGF-PKD1-HDAC7 axis, which regulates the EPCs angiogenesis by PKD1, but not the ERK and PI3K pathway.
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PMID:VEGF-PKD1-HDAC7 signaling promotes endothelial progenitor cell migration and tube formation. 2418 20