Abstract
In ovine pars tuberalis cells which express high affinity Mel la melatonin receptors, the ability of melatonin to directly stimulate or inhibit AP-1 transcription factor gene expression was studied. Effects of melatonin upon mRNA expression by forskolin, serum and IGF-1 were also investigated. Northern analysis showed melatonin had no direct stimulatory nor inhibitory effect upon transcription or translation. Melatonin was able to significantly inhibit forskolin-stimulated induction of c-fos and jun B mRNA whilst forskolin had no effect upon c-jun or jun D. Induction of c-Fos translation by forskolin was also inhibited by melatonin. Serum induced c-fos and c-jun, but melatonin was unable to affect these changes. Similarly IGF-1 stimulated c-fos and melatonin had no effect upon this induction. From these results it can be concluded that melatonin has no independent effects on expression of the AP-1 genes, rather its primary function is to inhibit cell activities through cyclic AMP-dependent routes of gene activation.
Original language | English |
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Pages (from-to) | 71-80 |
Number of pages | 10 |
Journal | Molecular and Cellular Endocrinology |
Volume | 123 |
Issue number | 1 |
Publication status | Published - 14 Oct 1996 |
Keywords
- melatonin
- pars tuberalis
- gene expression
- c-fos
- AP-1
- pituitary
- ovine pituitary
- adenylate-cyclase
- protein-kinase
- FOS proteins
- cells
- secretion
- prolactin
- signal
- acid
- Jun