Publication Date:
1987-12-04
Description:
Ligand-induced decrease in cell-surface receptor number (homologous downregulation) is often due to rapid receptor internalization. Thyrotropin-releasing hormone (TRH), however, causes a slow downregulation of TRH receptors (TRH-Rs), with a half-time of approximately 12 hours, in GH3 rat pituitary cells. The mechanism of TRH-R downregulation was studied by monitoring TRH-evoked depolarizing currents in Xenopus oocytes injected with GH3 cell RNA as a bioassay for TRH-R messenger RNA (mRNA) activity. In GH3 cells, TRH caused a rapid decrease in TRH-R mRNA activity to 15 percent of control within 3 hours. Because the half-life of TRH-R mRNA activity in control cells was approximately 3 hours, the rapid decrease in mRNA activity was not due to inhibition of mRNA synthesis alone and may represent a post-transcriptional effect.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Oron, Y -- Straub, R E -- Traktman, P -- Gershengorn, M C -- New York, N.Y. -- Science. 1987 Dec 4;238(4832):1406-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Cornell University Medical College, New York, NY 10021.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2825350" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Female
;
Gene Expression Regulation/drug effects
;
Membrane Potentials
;
Neoplasm Proteins/metabolism
;
Oocytes/drug effects/*metabolism
;
Pituitary Neoplasms/pathology
;
RNA, Messenger/*biosynthesis
;
RNA, Neoplasm/biosynthesis
;
Rats
;
Receptors, Neurotransmitter/genetics/*metabolism
;
Receptors, Thyrotropin-Releasing Hormone
;
Thyrotropin-Releasing Hormone/metabolism/*pharmacology
;
Tumor Cells, Cultured/metabolism
;
Xenopus laevis
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink