Activation of mitogen-activated protein kinase phosphatase 2 by gonadotropin-releasing hormone.
In: Molecular and cellular endocrinology, Jg. 172 (2001-02-14), Heft 1-2, S. 79-89
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Zugriff:
The aim of these studies was to identify the signaling mechanism(s) that contribute to GnRH-induced expression of MAPK phosphatase (MKP)-2, a dual specificity phosphatase that selectively inactivates MAPKs. GnRH receptor activation induced MKP-2 expression in both clonal (alphaT3-1) and primary gonadotropes. Activation of PKC isozymes was sufficient and required for MKP-2 induction. Inhibition of the extracellular signal-regulated kinase (ERK) or c-Jun N-terminal kinase (JNK) but not the p38 MAPK cascade was sufficient to block GnRH-induced MKP-2 expression. Induction of MKP-2 by GnRH was dependent on elevation in intracellular Ca(2+). Inhibition of Ca(2+) influx through L-type voltage-gated calcium channels blocked GnRH-induced MKP-2 expression. Depletion of intracellular Ca(2+) stores with thapsigargin blocked MKP-2 activation by GnRH independent of ERK and JNK activity. These results support the conclusion that MKP-2 induction by GnRH occurs via MAPK-dependent and -independent pathways. One mechanism requires GnRH-induced ERK and JNK activation, while a second MAPK-independent pathway requires a thapsigargin-sensitive calcium signal.
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Activation of mitogen-activated protein kinase phosphatase 2 by gonadotropin-releasing hormone.
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Autor/in / Beteiligte Person: | Zhang, T ; Mulvaney, JM ; Roberson, MS |
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Zeitschrift: | Molecular and cellular endocrinology, Jg. 172 (2001-02-14), Heft 1-2, S. 79-89 |
Veröffentlichung: | Limerick : North Holland Publishing ; <i>Original Publication</i>: Amsterdam, North-Holland., 2001 |
Medientyp: | academicJournal |
ISSN: | 0303-7207 (print) |
DOI: | 10.1016/s0303-7207(00)00378-6 |
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