Rab1 interacts directly with the β2-adrenergic receptor to regulate receptor anterograde trafficking

2012 ◽  
Vol 393 (6) ◽  
pp. 541-546 ◽  
Author(s):  
Maha M. Hammad ◽  
Yi-Qun Kuang ◽  
Alexa Morse ◽  
Denis J. Dupré
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
G Protein ◽  
Adrenergic Receptor ◽  
Direct Interaction ◽  
Potential Interaction ◽  
G Protein Coupled Receptors ◽  
Endocytic Pathway ◽  
Β2 Adrenergic Receptor ◽  
G Protein Coupled

Abstract Very little is understood about the trafficking of G protein-coupled receptors (GPCRs) from the endoplasmic reticulum (ER) to the plasma membrane. Rab guanosine triphosphatases (GTPases) are known to participate in the trafficking of various GPCRs via a direct interaction during the endocytic pathway, but whether this occurs in the anterograde pathway is unknown. We evaluated the potential interaction of Rab1, a GTPase known to regulate β2-adrenergic receptor (β2AR) trafficking, and its effect on export from the ER. Our results show that GTP-bound Rab1 interacts with the F(x)6LL motif of β2AR. Receptors lacking the interaction motif fail to traffic properly, suggesting that a direct interaction with Rab1 is required for β2AR anterograde trafficking.

scholarly journals Identification of G Protein α Subunit-Palmitoylating Enzyme

2008 ◽  
Vol 29 (2) ◽  
pp. 435-447 ◽  
Author(s):  
Ryouhei Tsutsumi ◽  
Yuko Fukata ◽  
Jun Noritake ◽  
Tsuyoshi Iwanaga ◽  
Franck Perez ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
G Protein ◽  
Adrenergic Receptor ◽  
Fluorescence Recovery After Photobleaching ◽  
G Protein Coupled Receptors ◽  
Α Subunit ◽  
Cytoplasmic Face ◽  
G Protein Α Subunit ◽  
G Protein Coupled

ABSTRACT The heterotrimeric G protein α subunit (Gα) is targeted to the cytoplasmic face of the plasma membrane through reversible lipid palmitoylation and relays signals from G-protein-coupled receptors (GPCRs) to its effectors. By screening 23 DHHC motif (Asp-His-His-Cys) palmitoyl acyl-transferases, we identified DHHC3 and DHHC7 as Gα palmitoylating enzymes. DHHC3 and DHHC7 robustly palmitoylated Gαq, Gαs, and Gαi2 in HEK293T cells. Knockdown of DHHC3 and DHHC7 decreased Gαq/11 palmitoylation and relocalized it from the plasma membrane into the cytoplasm. Photoconversion analysis revealed that Gαq rapidly shuttles between the plasma membrane and the Golgi apparatus, where DHHC3 specifically localizes. Fluorescence recovery after photobleaching studies showed that DHHC3 and DHHC7 are necessary for this continuous Gαq shuttling. Furthermore, DHHC3 and DHHC7 knockdown blocked the α1A-adrenergic receptor/Gαq/11-mediated signaling pathway. Together, our findings revealed that DHHC3 and DHHC7 regulate GPCR-mediated signal transduction by controlling Gα localization to the plasma membrane.

Structure and Regulation of G Protein-Coupled Receptors: The β2-Adrenergic Receptor as a Model

1991 ◽  
pp. 1-39 ◽  
Author(s):  
Sheila Collins ◽  
Martin J. Lohse ◽  
Brian O'Dowd ◽  
Marc G. Caron ◽  
Robert J. Lefkowitz
Keyword(s):  
G Protein ◽  
Adrenergic Receptor ◽  
G Protein Coupled Receptors ◽  
Β2 Adrenergic Receptor ◽  
G Protein Coupled

scholarly journals Importance of regions outside the cytoplasmic tail of G-protein-coupled receptors for phosphorylation and dephosphorylation

2010 ◽  
Vol 428 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Austin U. Gehret ◽  
Patricia M. Hinkle
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Cytoplasmic Tail ◽  
Amino Acid Sequences ◽  
G Protein Coupled Receptors ◽  
Intracellular Loop ◽  
Cytoplasmic Tails ◽  
Β2 Adrenergic Receptor ◽  
G Protein Coupled ◽  
Terminal Domains

Two GPCRs (G-protein-coupled receptors), TRHR (thyrotropin-releasing hormone receptor) and β2AR (β2-adrenergic receptor), are regulated in distinct manners. Following agonist binding, TRHR undergoes rapid phosphorylation attributable to GRKs (GPCR kinases); β2AR is phosphorylated by both second messenger-activated PKA (protein kinase A) and GRKs with slower kinetics. TRHR co-internalizes with arrestin, whereas β2AR recruits arrestin, but internalizes without it. Both receptors are dephosphorylated following agonist removal, but TRHR is dephosphorylated much more rapidly while it remains at the plasma membrane. We generated chimaeras swapping the C-terminal domains of these receptors to clarify the role of different receptor regions in phosphorylation, internalization and dephosphorylation. β2AR with a TRHR cytoplasmic tail (β2AR–TRHR) and TRHR with a β2AR tail (TRHR–β2AR) signalled to G-proteins normally. β2AR–TRHR was phosphorylated well at the PKA site in the third intracellular loop, but poorly at GRK sites in the tail, whereas TRHR–β2AR was phosphorylated strongly at GRK sites in the tail (Ser355/Ser356 of the β2AR). Both chimaeric receptors exhibited prolonged, but weak, association with arrestin at the plasma membrane, but high-affinity arrestin interactions and extensive co-internalization of receptor with arrestin required a phosphorylated TRHR tail. In contrast, swapping C-terminal domains did not change the rates of phosphorylation and dephosphorylation or the dependence of TRHR dephosphorylation on the length of agonist exposure. Thus the interactions of GPCRs with GRKs and phosphatases are determined not simply by the amino acid sequences of the substrates, but by regions outside the cytoplasmic tails.

scholarly journals Misfolded G Protein-Coupled Receptors and Endocrine Disease. Molecular Mechanisms and Therapeutic Prospects

2021 ◽  
Vol 22 (22) ◽  
pp. 12329
Author(s):  
Alfredo Ulloa-Aguirre ◽  
Teresa Zariñán ◽  
Eduardo Jardón-Valadez
Keyword(s):  
Plasma Membrane ◽  
G Protein ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
G Protein Coupled Receptors ◽  
Membrane Receptors ◽  
Therapeutic Interventions ◽  
Endocrine Function ◽  
Receptor Protein ◽  
G Protein Coupled

Misfolding of G protein-coupled receptors (GPCRs) caused by mutations frequently leads to disease due to intracellular trapping of the conformationally abnormal receptor. Several endocrine diseases due to inactivating mutations in GPCRs have been described, including X-linked nephrogenic diabetes insipidus, thyroid disorders, familial hypocalciuric hypercalcemia, obesity, familial glucocorticoid deficiency [melanocortin-2 receptor, MC2R (also known as adrenocorticotropin receptor, ACTHR), and reproductive disorders. In these mutant receptors, misfolding leads to endoplasmic reticulum retention, increased intracellular degradation, and deficient trafficking of the abnormal receptor to the cell surface plasma membrane, causing inability of the receptor to interact with agonists and trigger intracellular signaling. In this review, we discuss the mechanisms whereby mutations in GPCRs involved in endocrine function in humans lead to misfolding, decreased plasma membrane expression of the receptor protein, and loss-of-function diseases, and also describe several experimental approaches employed to rescue trafficking and function of the misfolded receptors. Special attention is given to misfolded GPCRs that regulate reproductive function, given the key role played by these particular membrane receptors in sexual development and fertility, and recent reports on promising therapeutic interventions targeting trafficking of these defective proteins to rescue completely or partially their normal function.

Members of the G Protein-Coupled Receptor Kinase Family That Phosphorylate the β2-Adrenergic Receptor Facilitate Sequestration†

Biochemistry ◽  
1996 ◽  
Vol 35 (13) ◽  
pp. 4155-4160 ◽  
Author(s):  
Luc Ménard ◽  
Stephen S. G. Ferguson ◽  
Larry S. Barak ◽  
Lucie Bertrand ◽  
Richard T. Premont ◽  
...  
Keyword(s):  
G Protein ◽  
Adrenergic Receptor ◽  
Receptor Kinase ◽  
G Protein Coupled Receptor ◽  
Kinase Family ◽  
Β2 Adrenergic Receptor ◽  
G Protein Coupled
Sign in / Sign up

Export Citation Format

Share Document