Overexpression of the G protein G11alpha prevents desensitization of Ca2+ response to thyrotropin-releasing hormone
Language English Country Netherlands Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
10465349
DOI
10.1016/s0024-3205(99)00319-7
PII: S0024320599003197
Knihovny.cz E-resources
- MeSH
- Calcium Channel Blockers pharmacology MeSH
- Bradykinin pharmacology MeSH
- Cell Line MeSH
- Time Factors MeSH
- Egtazic Acid pharmacology MeSH
- Gene Expression MeSH
- Thyrotropin-Releasing Hormone agonists antagonists & inhibitors pharmacology MeSH
- Inositol Phosphates metabolism MeSH
- Rats MeSH
- Humans MeSH
- Nifedipine pharmacology MeSH
- GTP-Binding Proteins antagonists & inhibitors genetics metabolism MeSH
- Receptors, Thyrotropin-Releasing Hormone agonists antagonists & inhibitors genetics physiology MeSH
- Suramin pharmacology MeSH
- Thapsigargin pharmacology MeSH
- Transfection MeSH
- Calcium metabolism pharmacology MeSH
- Calcium Signaling drug effects MeSH
- Dose-Response Relationship, Drug MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Calcium Channel Blockers MeSH
- Bradykinin MeSH
- Egtazic Acid MeSH
- Thyrotropin-Releasing Hormone MeSH
- Inositol Phosphates MeSH
- Nifedipine MeSH
- GTP-Binding Proteins MeSH
- Receptors, Thyrotropin-Releasing Hormone MeSH
- Suramin MeSH
- Thapsigargin MeSH
- Calcium MeSH
Doubly transfected human embryonal kidney cells (clone E2M11 of the HEK 293 cell line) expressing both thyrotropin-releasing hormone (TRH) receptors and G11alpha protein in high amounts were used to analyze the desensitization phenomenon of the Ca2+-mobilizing pathway. Quite unexpectedly, we did not observe any significant desensitization of the [Ca2+]i response to TRH in these cells after repeated or prolonged incubation with the hormone (up to 5 h). Under the same conditions, the TRH-induced [Ca2+]i response was completely desensitized in the parent cell line (293-E2 cels) expressing TRH receptors alone. In both cell lines, inositol phosphate response was desensitized after TRH exposure, although basal levels of inositol phospates in TRH-pretreated cells were much higher than in "naive" TRH-unexposed cells. These data suggest a significant role of the G protein G11alpha in desensitization of the Ca2+-mobilizing pathway occuring after repeated or long-term exposure of target cells to TRH-receptor agonists.
References provided by Crossref.org
Biochemical and physiological insights into TRH receptor-mediated signaling
