| Autor: |
G H, Murdoch, M, Waterman, R M, Evans, M G, Rosenfeld |
| Rok vydání: |
1985 |
| Předmět: |
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| Zdroj: |
The Journal of biological chemistry. 260(21) |
| ISSN: |
0021-9258 |
| Popis: |
The polypeptide thyrotropin-releasing hormone (TRH) and epidermal growth factor (EGF) stimulate, within seconds to minutes, the transcription of the prolactin gene in a rat pituitary cell line (GH4). Because a series of agents that act to stimulate prolactin secretion fail to alter prolactin gene transcription, it is suggested that secretory events are neither obligatory for nor causal of hormone-induced transcriptional stimulation. Elevation of cytosolic-free calcium does not stimulate prolactin gene transcription; however, several agents that act to antagonize calcium-dependent processes inhibit or abolish both TRH and EGF stimulation of prolactin gene transcription and a specific hormone-dependent nuclear phosphorylation. In contrast, inhibitors of the slow calcium channel exert minimal effects on TRH-stimulated prolactin gene expression, suggesting that calcium influx through membrane channels is not crucial for the observed nuclear actions of TRH. Activation of protein kinase C by phorbol esters mimics the nuclear actions of TRH. In the presence of increased intracellular calcium levels, the effects of 12-O-tetradecanoyl phorbol 13-acetate on prolactin gene transcription are quantitatively identical to those observed in response to TRH or EGF. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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