Journal article
Polarity of TRH receptors in transfected MDCK cells is independent of endocytosis signals and G protein coupling
American Journal of Physiology: Cell Physiology, Vol.270(3), pp.C753-C762
03/01/1996
DOI: 10.1152/ajpcell.1996.270.3.C753
PMID: 8638654
Abstract
Information concerning the molecular sorting of G protein-coupled receptors in polarized epithelial cells is limited. Therefore, we have expressed the receptor for thyrotropin-releasing hormone (TRH) in Madin-Darby canine kidney (MDCK) cells by adenovirus-mediated gene transfer to determine its distribution in a model cell system and to begin analyzing the molecular information responsible for its distribution. Equilibrium binding of [methyl-3H]TRH to apical and basolateral surfaces of polarized MDCK cells reveals that TRH receptors are expressed predominantly (>80%) on the basolateral cell surface. Receptors undergo rapid endocytosis following agonist binding; up to 80% are internalized in 15 min. A mutant receptor missing the last 59 residues, C335Stop, is poorly internalized (<10%) but is nevertheless basolaterally expressed (>85%). A second mutant TRH receptor, delta218-263, lacks essentially all of the third intracellular loop and is not coupled to G proteins on binding agonist. This receptor internalizes TRH approximately half as efficiently as wild-type TRH receptors but is nevertheless strongly polarized to the basolateral surface (>90%). These results indicate that molecular sequences responsible for basolateral accumulation of TRH receptors can be segregated from signals for ligand-induced receptor endocytosis and coupling to heterotrimeric G proteins.
Details
- Title: Subtitle
- Polarity of TRH receptors in transfected MDCK cells is independent of endocytosis signals and G protein coupling
- Creators
- C Yeaman - Department of Cell Biology and Anatomy, Cornell University MedicalCollege, New York, New York 10021, USAM Heinflink - Department of Cell Biology and Anatomy, Cornell University MedicalCollege, New York, New York 10021, USAE Falck-Pedersen - Department of Cell Biology and Anatomy, Cornell University MedicalCollege, New York, New York 10021, USAE Rodriguez-Boulan - Department of Cell Biology and Anatomy, Cornell University MedicalCollege, New York, New York 10021, USAM. C Gershengorn - Department of Cell Biology and Anatomy, Cornell University MedicalCollege, New York, New York 10021, USA
- Resource Type
- Journal article
- Publication Details
- American Journal of Physiology: Cell Physiology, Vol.270(3), pp.C753-C762
- DOI
- 10.1152/ajpcell.1996.270.3.C753
- PMID
- 8638654
- ISSN
- 0363-6143
- eISSN
- 1522-1563
- Language
- English
- Date published
- 03/01/1996
- Academic Unit
- Anatomy and Cell Biology; Internal Medicine
- Record Identifier
- 9984025697402771
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