?
Integral membrane protein GPR137B, an orphan receptor member of the seven-transmembrane G protein-coupled receptor superfamily GPR137B, also called transmembrane 7 superfamily member 1 (TM7SF1), is a lysosome integral membrane protein that is strongly expressed in the heart, liver, kidney, and brain. It is an orphan G protein-coupled receptor (GPCR) associated with M2 macrophage polarization, and has been shown to perform a regulatory function in controlling dynamic Rag and mTORC1 localization and activity, as well as lysosome morphology. It also plays a role in bone remodeling in mouse and zebrafish, functioning as a negative regulator of osteoclast activity essential for normal resorption and patterning of the skeleton. GPCRs transmit physiological signals from the outside of the cell to the inside via G proteins. All GPCRs share a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",