Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IGF-I induces alpha(1B)-adrenoceptor (alpha(1B)-AR) phosphorylation. The effect of IGF-I was rapid and transient, reaching near-maximal values at 10 min and decreasing after 30 min; it was observed at low IGF-I concentrations (EC(50) approximately 10 ng/ml) and was associated to receptor desensitization as evidenced by a decreased alpha(1B)-adrenergic effect on intracellular calcium and production of inositol phosphates. The effect of IGF-I was markedly decreased in cells treated with pertussis toxin suggesting involvement of pertussis toxin-sensitive G proteins. Transfection of the carboxyl terminus of the beta-adrenergic receptor kinase or the Deltap85 mutant of phosphoinositide 3-kinase (PI3K) markedly decreased the alpha(1B)-AR phosphorylation induced by IGF-I without decreasing the receptor phosphorylation induced by noradrenaline. Inhibitors of PI3K and protein kinase C blocked IGF-I-induced alpha(1B)-AR phosphorylation. In addition, it was observed that AG1478, an inhibitor of the epidermal growth factor (EGF) receptor kinase, and BB-94, a metalloproteinase inhibitor, also diminished IGF-I-induced adrenoceptor phosphorylation. The data clearly show that IGF-I triggers a complex signaling pathway, which leads to the phosphorylation and desensitization of a serpentine G protein-coupled receptor, suggesting the following hypothetical model: 1) stimulation of IGF-I receptors activate pertussis toxin-sensitive G proteins; 2) the growth factor action activates metalloproteinases, which catalyze heparin binding-EGF shedding, and transactivation of EGF receptors, and 3) dissociated Gbetagamma subunits and phosphotyrosine residues seem to trigger PI3K activity, which leads to activation of protein kinase C, resulting in alpha(1B)-AR phosphorylation and desensitization.
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PMID:Insulin-like growth factor-I induces alpha(1B)-adrenergic receptor phosphorylation through G beta gamma and epidermal growth factor receptor transactivation. 1680 66

Jab1 is a co-activator of activating protein-1 (AP-1) transcription factor and the fifth subunit of the constitutive photomorphogenesis 9 (COP9) signalosome, which has been shown to mediate nuclear exportation and ubiquitin-dependent degradation of the tumor suppressor p27(Kip1). Jab1 is overexpressed in several types of human cancer. However, de-regulation of Jab1 gene expression in cancer cells is largely unclear. In this study, we reported that expression of Jab1 was stimulated by HER-2/neu oncogene via transcriptional activation. Promoter deletion and mutation analysis indicated that HER-2/neu stimulated Jab1 via the T cell factor (TCF) binding site located at the -380/-368 region of the human Jab1 promoter. DNA affinity precipitation assay and chromatin immunoprecipitation assay verified that binding of beta-catenin and TCF-4 to this consensus site was increased by HER-2/neu. In addition, dominant-negative mutant of TCF significantly attenuated the stimulatory effect of HER-2/neu. We also demonstrated that HER-2/neu increased beta-catenin/TCF-mediated Jab1 expression via the AKT signaling pathway because chemical inhibitor or dominant-negative mutant of AKT effectively attenuated the stimulatory action of HER-2/neu. IGF-I, which is a well-known AKT activator, also up-regulated the expression of Jab1 in NIH/3T3 and MCF-7 cells. Knockdown of Jab1 by small interfering RNA (siRNA) preferentially inhibited proliferation of HER-2/neu-overexpressing breast cancer cells. Taken together, our results suggest that HER-2/neu transcriptionally activates Jab1 expression to promote proliferation of breast cancer cells.
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PMID:HER-2/neu transcriptionally activates Jab1 expression via the AKT/beta-catenin pathway in breast cancer cells. 1791 96

In this study, we assessed the importance of insulin-like growth factor (IGF) and epidermal growth factor (EGF) receptor co-signaling for rat neural precursor (NP) cell proliferation and self-renewal in the context of a developmental brain injury that is associated with cerebral palsy. Consistent with previous studies, we found that there is an increase in the in vitro growth of subventricular zone NPs isolated acutely after cerebral hypoxia-ischemia; however, when cultured in medium that is insufficient to stimulate the IGF type 1 receptor, neurosphere formation and the proliferative capacity of those NPs was severely curtailed. This reduced growth capacity could not be attributed simply to failure to survive. The growth and self-renewal of the NPs could be restored by addition of both IGF-I and IGF-II. Since the size of the neurosphere is predominantly due to cell proliferation we hypothesized that the IGFs were regulating progression through the cell cycle. Analyses of cell cycle progression revealed that IGF-1R activation together with EGFR co-signaling decreased the percentage of cells in G1 and enhanced cell progression into S and G2. This was accompanied by increases in expression of cyclin D1, phosphorylated histone 3, and phosphorylated Rb. Based on these data, we conclude that coordinate signaling between the EGF receptor and the IGF type 1 receptor is necessary for the normal proliferation of NPs as well as for their reactive expansion after injury. These data indicate that manipulations that maintain or amplify IGF signaling in the brain during recovery from developmental brain injuries will enhance the production of new brain cells to improve neurological function in children who are at risk for developing cerebral palsy.
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PMID:Insulin-Like Growth Factor Receptor Signaling is Necessary for Epidermal Growth Factor Mediated Proliferation of SVZ Neural Precursors in vitro Following Neonatal Hypoxia-Ischemia. 2490 23


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