A1/A2A	Adenosine receptor type 1/type 2A
α1b	α1b adrenergic receptor
AT1/AT2	Angiotensin II receptor type 1/type 2
β2AR	β2 Adrenergic receptor
BiFC	Bimolecular fluorescence complementation assay
BiLC	Bimolecular luminescence complementation assay
BRET	Bioluminescence resonance energy transfer
CAD	Cath.-a-differentiated
cAMP	Cyclic adenosine monophosphate
CB1	Cannabinoid receptor 1
CC	C-terminal fragment of split Cerulean
CFP	Cerulean fluorescent protein
CC2	C-C chemokine receptor type 2
CFLuc	C-terminal fragment of split Firefly luciferase
CGFP	C-terminal fragment of split green fluorescent protein
CID	Chemically induced dimerization
CN	N-terminal fragment of split Cerulean
CODA-RET	Complemented donor–acceptor resonance energy transfer
co-IP	Co-immunoprecipitation
CPA	N6-cyclopentyladenosine
CXCR4/CXCR7	C-X-C chemokine receptor type 4/type 7
D1R/D2R/D3R	Dopamine receptor type 1/type 2/type 3
D2LR	Dopamine receptor type 2 long isoform
D2SR	Dopamine receptor type 2 short isoform
DsRed	Discosoma Red
ECL	Extracellular loop
EGFP	Enhanced green fluorescent protein
FLuc	Firefly Luciferase
FFAR2/3	Free fatty acid receptor type 2/type 3
FRB	FKBP-rapamycin binding domain of mTOR
FKBP12	FK506- and rapamycin-binding protein
FRET	Förster resonance energy transfer
GHSR1a	Growth hormone secretagogue receptor 1α
GLuc	Gaussia princeps luciferase
GPCR	G protein-coupled receptor
GRK	G protein-coupled receptor kinase
HEK	Human embryonic kidney
Homo-FC	Homo-molecular fluorescence complementation
5-HTR	5-hydroxytryptamine receptor
HTS	High-throughput screening
L-DOPA	L-3,4-dihydroxyphenylalanine
LcBiT	C-terminal fragment of split large BiT
LgBiT	Large BiT, large subunit of Nanoluciferase
LnBiT	N-terminal fragment of split large BiT
M1/M2/M4	Muscarinic acetylcholine receptor type 1/type 2/type 4
MAPK	Mitogen activated protein kinase
MBiFC	Multicolor Bimolecular fluorescence complementation assay
MC4R	Melanocortin 4 receptor
MOP	Mu-opioid receptor
MRAP2	Melanocortin 2 receptor accessory protein 2
α-MSH	α-Melanocyte- stimulating hormone
mGluR2/mGLuR5/mGluR6	Metabotropic glutamate receptor type 2/type 5/type 6
mRFP	Monomer red fluorescent protein
NanoBiT®	NanoLuc Binary Technology®
NFLuc	N-terminal fragment of split Firefly luciferase
NGFP	N-terminal fragment of split green fluorescent protein
NPFF2	Neuropeptide FF receptor 2
NPY	Neuropeptide Y
OX1R	Orexin 1 receptor
PCA	Protein complementation assay
PLA	Proximity ligation assay
PPI	Protein–protein interaction
P2RY1	P2Y purinoceptor 1
RLuc	Renilla Luciferase
SDS-PAGE	Sodium dodecyl sulfate–polyacrylamide gel electrophoresis
SH3	SRC Homology 3 Domain
SmBiT	Small BiT, small subunit of Nanoluciferase
SpIDA	Spatial intensity distribution analysis
SRET	Sequential resonance energy transfer
TAT	Transactivator of transcription
TM	Transmembrane
TSHr	Thyrotropin receptor
VC	C-terminal fragment of split Venus
VN	N-terminal fragment of split Venus
YC	C-terminal fragment of split yellow fluorescent protein
YFP	Yellow fluorescent protein
YN	N-terminal fragment of split yellow fluorescent protein