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)

MKK7 is a recently discovered mitogen-activated protein kinase (MAPK) kinase that is unique in that it specifically activates only the c-JUN NH(2)-terminal protein kinase (JNK) family of enzymes. Very little is known about the biological role of MKK7. We generated inducible cell lines from the human embryonal kidney carcinoma cell line, HEK293, by stable transfection with a constitutively active mutant of MKK7, MKK7(3E), fused to green fluorescent protein (GFP), under the control of an ecdysone-inducible promoter. Treatment of cells with the synthetic ecdysone analog ponasterone A induced expression of GFP-MKK7(3E) and resulted in sustained activation of endogenous JNK, but neither of the other endogenous MAPKs, ERK or p38. Red and green fluorescing cDNA copies of mRNA extracted from cells obtained before and after induction of GFP-MKK7(3E) were hybridized to microarrays containing more than 6,000 cDNAs in eight independent experiments. By selection criteria, 23 genes were differentially regulated after 24 h of induction of GFP-MKK7(3E) and 16 after 48 h. The expression of 9 genes was consistently changed after both 24 and 48 h of induction. These changes included down-regulation of three genes, c-myc, angiopoietin-2, and glucose-regulated protein 58, and up-regulation of 6 genes, tissue factor pathway inhibitor-2, GRP78, autotaxin, PPP1R7, the DKFZ cDNA p434D0818, and 1 unknown gene. Consistent with previously described roles of several of the altered genes, MKK7(3E) inhibited cell proliferation. These data implicate active MKK7 in the negative regulation of cell proliferation and provide evidence for a new role for this kinase in the regulation of a distinct, hitherto unrecognized set of genes.
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PMID:Inducible expression of a constitutively active mutant of mitogen-activated protein kinase kinase 7 specifically activates c-JUN NH2-terminal protein kinase, alters expression of at least nine genes, and inhibits cell proliferation. 1171 98

Human tissue factor pathway inhibitor-2 (hTFPI-2) is a 32-kDa serine protease inhibitor that is associated with the extracellular matrix. hTFPI-2 inhibits several extracellular matrix-degrading serine proteases and may play a role in tumor invasion and metastasis. To study the signal transduction pathway that leads to the activation of the hTFPI-2, we cloned the potential promoter region of this gene adjacent to a heterologous luciferase reporter gene. Phorbol 12-myristate 13-acetate (PMA) induced the luciferase reporter gene in HEK293 cells and other epithelial cell lines, such as the human lung carcinoma A549 cells, the breast carcinoma MCF7 cells, and the cervical HeLa cells. This PMA induction was blocked with the MEK inhibitor UO126, suggesting that the PMA-induced activation of the hTFPI-2 promoter is mediated through MEK. Furthermore, epidermal growth factor induced the luciferase reporter gene in HeLa cells. Cotransfection of the luciferase construct with constitutively active components of the Ras/Raf/MEK/ERK pathway in EcR-293 cells lead to a 7- to 92-fold induction of the luciferase reporter gene, indicating that regulation of hTFPI-2 is mediated through this pathway. A series of luciferase reporter gene constructs with progressive deletions of the 5'-flanking region suggested that the minimal basal promoter activity is located between nucleotide positions -89 and -384, whereas the minimal inducible promoter activity is between -89 and -222. We have used the computer program TFSEARCH and mutagenesis to analyze potential transcription factor binding sites. We identified an AP-1 binding site at nucleotide position -156 (inducible activity) and a Sp1 site at position -134 (basal activity) as potential cis-acting elements in the promoter region of the hTFPI-2.
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PMID:The ERK/MAPK pathway regulates the activity of the human tissue factor pathway inhibitor-2 promoter. 1244 83