Structural architecture of a dimeric class C GPCR based on co-trafficking of sweet taste receptor subunits

Jihye Park, Balaji Selvam, Keisuke Sanematsu, Noriatsu Shigemura, Diwakar Shukla, Erik Procko

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Class C G protein– coupled receptors (GPCRs) are obligatory dimers that are particularly important for neuronal responses to endogenous and environmental stimuli. Ligand recognition through large extracellular domains leads to the reorganization of transmembrane regions to activate G protein signaling. Although structures of individual domains are known, the complete architecture of a class C GPCR and the mechanism of interdomain coupling during receptor activation are unclear. By screening a mutagenesis library of the human class C sweet taste receptor subunit T1R2, we enhanced surface expression and identified a dibasic intracellular retention motif that modulates surface expression and co-trafficking with its heterodimeric partner T1R3. Using a highly expressed T1R2 variant, dimerization sites along the entire subunit within all the structural domains were identified by a comprehensive mutational scan for co-trafficking with T1R3 in human cells. The data further reveal that the C terminus of the extracellular cysteine-rich domain needs to be properly folded for T1R3 dimerization and co-trafficking, but not for surface expression of T1R2 alone. These results guided the modeling of the T1R2–T1R3 dimer in living cells, which predicts a twisted arrangement of domains around the central axis, and a continuous folded structure between transmembrane domain loops and the cysteine-rich domains. These insights have implications for how conformational changes between domains are coupled within class C GPCRs.

Original languageEnglish
Pages (from-to)4759-4774
Number of pages16
JournalJournal of Biological Chemistry
Volume294
Issue number13
DOIs
Publication statusPublished - Jan 1 2019

Fingerprint

G-Protein-Coupled Receptors
Dimerization
Dimers
Cysteine
Cells
Mutagenesis
GTP-Binding Proteins
Libraries
Screening
Chemical activation
Ligands

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Structural architecture of a dimeric class C GPCR based on co-trafficking of sweet taste receptor subunits. / Park, Jihye; Selvam, Balaji; Sanematsu, Keisuke; Shigemura, Noriatsu; Shukla, Diwakar; Procko, Erik.

In: Journal of Biological Chemistry, Vol. 294, No. 13, 01.01.2019, p. 4759-4774.

Research output: Contribution to journalArticle

@article{2aa7e084162c46429afdf5ec71779ce1,
title = "Structural architecture of a dimeric class C GPCR based on co-trafficking of sweet taste receptor subunits",
abstract = "Class C G protein– coupled receptors (GPCRs) are obligatory dimers that are particularly important for neuronal responses to endogenous and environmental stimuli. Ligand recognition through large extracellular domains leads to the reorganization of transmembrane regions to activate G protein signaling. Although structures of individual domains are known, the complete architecture of a class C GPCR and the mechanism of interdomain coupling during receptor activation are unclear. By screening a mutagenesis library of the human class C sweet taste receptor subunit T1R2, we enhanced surface expression and identified a dibasic intracellular retention motif that modulates surface expression and co-trafficking with its heterodimeric partner T1R3. Using a highly expressed T1R2 variant, dimerization sites along the entire subunit within all the structural domains were identified by a comprehensive mutational scan for co-trafficking with T1R3 in human cells. The data further reveal that the C terminus of the extracellular cysteine-rich domain needs to be properly folded for T1R3 dimerization and co-trafficking, but not for surface expression of T1R2 alone. These results guided the modeling of the T1R2–T1R3 dimer in living cells, which predicts a twisted arrangement of domains around the central axis, and a continuous folded structure between transmembrane domain loops and the cysteine-rich domains. These insights have implications for how conformational changes between domains are coupled within class C GPCRs.",
author = "Jihye Park and Balaji Selvam and Keisuke Sanematsu and Noriatsu Shigemura and Diwakar Shukla and Erik Procko",
year = "2019",
month = "1",
day = "1",
doi = "10.1074/jbc.RA118.006173",
language = "English",
volume = "294",
pages = "4759--4774",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "13",

}

TY - JOUR

T1 - Structural architecture of a dimeric class C GPCR based on co-trafficking of sweet taste receptor subunits

AU - Park, Jihye

AU - Selvam, Balaji

AU - Sanematsu, Keisuke

AU - Shigemura, Noriatsu

AU - Shukla, Diwakar

AU - Procko, Erik

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Class C G protein– coupled receptors (GPCRs) are obligatory dimers that are particularly important for neuronal responses to endogenous and environmental stimuli. Ligand recognition through large extracellular domains leads to the reorganization of transmembrane regions to activate G protein signaling. Although structures of individual domains are known, the complete architecture of a class C GPCR and the mechanism of interdomain coupling during receptor activation are unclear. By screening a mutagenesis library of the human class C sweet taste receptor subunit T1R2, we enhanced surface expression and identified a dibasic intracellular retention motif that modulates surface expression and co-trafficking with its heterodimeric partner T1R3. Using a highly expressed T1R2 variant, dimerization sites along the entire subunit within all the structural domains were identified by a comprehensive mutational scan for co-trafficking with T1R3 in human cells. The data further reveal that the C terminus of the extracellular cysteine-rich domain needs to be properly folded for T1R3 dimerization and co-trafficking, but not for surface expression of T1R2 alone. These results guided the modeling of the T1R2–T1R3 dimer in living cells, which predicts a twisted arrangement of domains around the central axis, and a continuous folded structure between transmembrane domain loops and the cysteine-rich domains. These insights have implications for how conformational changes between domains are coupled within class C GPCRs.

AB - Class C G protein– coupled receptors (GPCRs) are obligatory dimers that are particularly important for neuronal responses to endogenous and environmental stimuli. Ligand recognition through large extracellular domains leads to the reorganization of transmembrane regions to activate G protein signaling. Although structures of individual domains are known, the complete architecture of a class C GPCR and the mechanism of interdomain coupling during receptor activation are unclear. By screening a mutagenesis library of the human class C sweet taste receptor subunit T1R2, we enhanced surface expression and identified a dibasic intracellular retention motif that modulates surface expression and co-trafficking with its heterodimeric partner T1R3. Using a highly expressed T1R2 variant, dimerization sites along the entire subunit within all the structural domains were identified by a comprehensive mutational scan for co-trafficking with T1R3 in human cells. The data further reveal that the C terminus of the extracellular cysteine-rich domain needs to be properly folded for T1R3 dimerization and co-trafficking, but not for surface expression of T1R2 alone. These results guided the modeling of the T1R2–T1R3 dimer in living cells, which predicts a twisted arrangement of domains around the central axis, and a continuous folded structure between transmembrane domain loops and the cysteine-rich domains. These insights have implications for how conformational changes between domains are coupled within class C GPCRs.

UR - http://www.scopus.com/inward/record.url?scp=85063957629&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85063957629&partnerID=8YFLogxK

U2 - 10.1074/jbc.RA118.006173

DO - 10.1074/jbc.RA118.006173

M3 - Article

C2 - 30723160

AN - SCOPUS:85063957629

VL - 294

SP - 4759

EP - 4774

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 13

ER -