Journal article
Trans-Golgi Network (TGN) as a Regulatory Node for β1-Adrenergic Receptor (β1AR) Down-modulation and Recycling
The Journal of biological chemistry, Vol.287(17), pp.14178-14191
04/20/2012
DOI: 10.1074/jbc.M111.323782
PMCID: PMC3340205
PMID: 22378779
Abstract
Background:
The
trans
-Golgi network (TGN) has been implicated in G protein-coupled receptor (GPCR) recycling and proteasomal degradation of endocytosed receptors.
Results:
Endocytosed β1AR employs the TGN as a checkpoint for recycling and lysosomal degradation.
Conclusion:
The TGN is an important organelle for determining the endocytic fate of β1AR.
Significance:
The TGN not only regulates surface expression during GPCR export but also determines the fate of endocytosed GPCRs.
Receptor down-modulation is the key mechanism by which G protein-coupled receptors (GPCRs) prevent excessive receptor signaling in response to agonist stimulation. Recently, the
trans
-Golgi network (TGN) has been implicated as a key checkpoint for receptor endocytosis and degradation. Here, we investigated the involvement of the TGN in down-modulation of β1-adrenergic receptor in response to persistent isoprotenerol stimulation. Immunofluorescent staining showed that ∼50% of endocytosed β1AR colocalized with TGN-46 at 5 h. Disruption of the TGN by brefeldin A (BFA) led to the robust accumulation of endocytosed β1AR in Rab11
+
recycling endosomes, inhibited β1AR entry into LAMP1
+
lysosomes, and as a result enhanced β1AR recycling to the plasma membrane. The lysosomotropic agent, chloroquine, arrested the majority of endocytosed β1AR in the TGN by 4 h. Immunoblot analysis showed that either disruption of the TGN or blockage of the lysosome prevented β1AR degradation. Co-expression of GFP-arrestin-3 in β1AR cells increased the endocytosis of β1AR and facilitated its entry to the TGN but inhibited recycling to the plasma membrane. Arrestin-3-induced inhibition of β1AR recycling was reversed by BFA treatment, whereas chloroquine induced the accumulation of arrestin-3 with β1AR in the TGN. These results demonstrate for the first time that the TGN acts as a checkpoint for both the recycling and down-regulation of β1AR and that arrestin-3 not only mediates β1AR endocytosis but also its recycling through the TGN.
Details
- Title: Subtitle
- Trans-Golgi Network (TGN) as a Regulatory Node for β1-Adrenergic Receptor (β1AR) Down-modulation and Recycling
- Creators
- Shi-Bin Cheng - From the Division of Hematology and Oncology, Rhode Island Hospital and Brown University, Providence, Rhode Island 02903Edward J Filardo - From the Division of Hematology and Oncology, Rhode Island Hospital and Brown University, Providence, Rhode Island 02903
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.287(17), pp.14178-14191
- DOI
- 10.1074/jbc.M111.323782
- PMID
- 22378779
- PMCID
- PMC3340205
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- American Society for Biochemistry and Molecular Biology; 9650 Rockville Pike, Bethesda, MD 20814, U.S.A
- Grant note
- R01 CA119165-01A2 / National Institutes of Health
- Alternative title
- β1AR Down-regulation via TGN
- Language
- English
- Date published
- 04/20/2012
- Academic Unit
- Pharmaceutical Sciences and Experimental Therapeutics; Surgery; Internal Medicine
- Record Identifier
- 9984051779602771
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