G-protein linked receptors are defined as

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G-protein linked receptors are defined as

G-protein coupled receptors are defined by seven transmembrane domains and a cytoplasmic region that binds and activates heterotrimeric G proteins. When a ligand binds outside the cell, the receptor undergoes a conformational change that lets its cytoplasmic tail interact with a G protein, promoting GDP-GTP exchange on the Gα subunit and triggering downstream signaling. This arrangement distinguishes them from ion channels (which are themselves channels for ions), intracellular receptors that bind steroid hormones and typically regulate gene transcription, and receptors that lack a cytoplasmic domain and thus cannot engage G proteins. So the description of a seven‑pass membrane receptor with a cytoplasmic G-protein–binding region best identifies GPCRs.

G-protein coupled receptors are defined by seven transmembrane domains and a cytoplasmic region that binds and activates heterotrimeric G proteins. When a ligand binds outside the cell, the receptor undergoes a conformational change that lets its cytoplasmic tail interact with a G protein, promoting GDP-GTP exchange on the Gα subunit and triggering downstream signaling. This arrangement distinguishes them from ion channels (which are themselves channels for ions), intracellular receptors that bind steroid hormones and typically regulate gene transcription, and receptors that lack a cytoplasmic domain and thus cannot engage G proteins. So the description of a seven‑pass membrane receptor with a cytoplasmic G-protein–binding region best identifies GPCRs.

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