التفاصيل البيبلوغرافية
| العنوان: |
Activation and nuclear translocation of PKCδ, Pyk2 and ERK1/2 by gonadotropin releasing hormone in HEK293 cells |
| المؤلفون: |
Farshori, Parvaiz Q., Shah, Bukhtiar H., Arora, Krishan K.1, Martinez-Fuentes, Antonio1, Catt, Kevin J. catt@helix.nih.gov |
| المصدر: |
Journal of Steroid Biochemistry & Molecular Biology. Jun2003, Vol. 85 Issue 2-5, p337. 11p. |
| مصطلحات موضوعية: |
*PHOSPHORYLATION, *GONADOTROPIN releasing hormone, *CHROMOSOMAL translocation |
| مستخلص: |
The mechanism of agonist-induced activation of Pyk2 and its relationship with ERK1/2 phosphorylation was analyzed in HEK293 cells stably expressing the gonadotropin releasing hormone (GnRH) receptor. GnRH stimulation caused rapid and sustained phosphorylation of ERK1/2 and Pyk2 that was accompanied by their nuclear translocation. Pyk2 was also localized on cell membranes and at focal adhesions. Dominant negative Pyk2 (PKM) had no effect on GnRH-induced ERK1/2 phosphorylation and c-fos expression. These actions of GnRH on ERK1/2 and Pyk2 were mimicked by activation of protein kinase C (PKC) and were abolished by its inhibition. GnRH caused translocation of PKCα and δ, but not of ϵ, ι and λ, to the cell membrane, as well as phosphorylation of Raf at Ser338, a major site in the activation of MEK/ERK1/2. Stimulation of HEK293 cells by EGF caused marked ERK1/2 phosphorylation that was attenuated by the selective EGFR receptor (EGF-R) kinase inhibitor, AG1478. However, GnRH-induced ERK1/2 activation was independent of EGF-R activation. These results indicate that activation of PKC is responsible for GnRH-induced phosphorylation of both ERK1/2 and Pyk2, and that Pyk2 activation does not contribute to GnRH signaling. Moreover, GnRH-induced phosphorylation of ERK1/2 and expression of c-fos in HEK293 cells is independent of Src and EGF-R transactivation, and is mediated through the PKC/Raf/MEK cascade. [Copyright &y& Elsevier] |
| قاعدة البيانات: |
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