Arrestin-independent constitutive endocytosis of GPR125/ADGRA3

TY - JOUR

T1 - Arrestin-independent constitutive endocytosis of GPR125/ADGRA3

AU - Spiess, Katja

AU - Bagger, Sofie O.

AU - Torz, Lola J.

AU - Jensen, Kristian H. R.

AU - Walser, Anna L.

AU - Kvam, Jone M.

AU - Mogelmose, Ann-Sofie K.

AU - Daugvilaite, Viktorija

AU - Junnila, Riia K.

AU - Hjorto, Gertrud M.

AU - Rosenkilde, Mette M.

PY - 2019

Y1 - 2019

N2 - The orphan receptor GPR125 (ADGRA3) belongs to subgroup III of the adhesion G protein−coupled receptor (aGPCR) family. aGPCRs, also known as class B2 GPCRs, share basic structural and functional properties with other GPCRs. Many of them couple to G proteins and activate G protein−dependent and −independent signaling pathways, but little is known about aGPCR internalization and β-arrestin recruitment. GPR125 was originally described as a spermatogonial stem cell marker and studied for its role in Wnt signaling and cell polarity. Here, using cell-based assays and confocal microscopy, we show that GPR125 is expressed on the cell surface and undergoes constitutive endocytosis in a β-arrestin−independent, but clathrin-dependent manner, as indicated by colocalization with transferrin receptor 1, an early endosome marker. These data support that the constitutive internalization of GPR125 contributes to its biological functions by controlling receptor surface expression and accessibility for ligands. Our study sheds light on a new property of aGPCRs, namely internalization; a property described to be important for signal propagation, signal termination, and desensitization of class A (rhodopsin-like) and B1 (VIP/secretin) GPCRs.

AB - The orphan receptor GPR125 (ADGRA3) belongs to subgroup III of the adhesion G protein−coupled receptor (aGPCR) family. aGPCRs, also known as class B2 GPCRs, share basic structural and functional properties with other GPCRs. Many of them couple to G proteins and activate G protein−dependent and −independent signaling pathways, but little is known about aGPCR internalization and β-arrestin recruitment. GPR125 was originally described as a spermatogonial stem cell marker and studied for its role in Wnt signaling and cell polarity. Here, using cell-based assays and confocal microscopy, we show that GPR125 is expressed on the cell surface and undergoes constitutive endocytosis in a β-arrestin−independent, but clathrin-dependent manner, as indicated by colocalization with transferrin receptor 1, an early endosome marker. These data support that the constitutive internalization of GPR125 contributes to its biological functions by controlling receptor surface expression and accessibility for ligands. Our study sheds light on a new property of aGPCRs, namely internalization; a property described to be important for signal propagation, signal termination, and desensitization of class A (rhodopsin-like) and B1 (VIP/secretin) GPCRs.

KW - adhesion GPCR

KW - GPR125

KW - ADGRA3

KW - internalization

KW - endocytosis

KW - beta-arrestin

U2 - 10.1111/nyas.14263

DO - 10.1111/nyas.14263

M3 - Journal article

C2 - 31659746

SN - 0077-8923

JO - Annals of The Lyceum of Natural History of New York

JF - Annals of The Lyceum of Natural History of New York

ER -