Sustained neurotensin exposure promotes cell surface recruitment of NTS2 receptors
- Montreal Neurological Institute, McGill University, Montreal, Que., H3A 2B4 (Canada)
- Institut de Pharmacologie Moleculaire et Cellulaire, CNRS, Sophia Antipolis, 06560 Valbonne (France)
In this study, we investigated whether persistent agonist stimulation of NTS2 receptors gives rise to down-regulation, in light of reports that their activation induced long-lasting effects. To address this issue, we incubated COS-7 cells expressing the rat NTS2 with neurotensin (NT) for up to 24 h and measured resultant cell surface [{sup 125}I]-NT binding. We found that NTS2-expressing cells retained the same surface receptor density despite efficient internalization mechanisms. This preservation was neither due to NTS2 neosynthesis nor recycling since it was not blocked by cycloheximide or monensin. However, it appeared to involve translocation of spare receptors from internal stores, as NT induced NTS2 migration from trans-Golgi network to endosome-like structures. This stimulation-induced regulation of cell surface NTS2 receptors was even more striking in rat spinal cord neurons. Taken together, these results suggest that sustained NTS2 activation promotes recruitment of intracellular receptors to the cell surface, thereby preventing functional desensitization.
- OSTI ID:
- 20798943
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 343, Issue 3; Other Information: DOI: 10.1016/j.bbrc.2006.03.047; PII: S0006-291X(06)00533-X; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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