After receptor activation, a GPCR commonly transduces the signal via

Prepare for the Foundations of Biology Exam 1. Dive into key biological concepts with multiple choice questions, hints, and explanations. Ace the exam with our efficient study methods!

Multiple Choice

After receptor activation, a GPCR commonly transduces the signal via

GPCRs convey signals by activating heterotrimeric G-proteins. When a ligand binds, the receptor changes shape and acts as a guanine nucleotide exchange factor for the Gα subunit, promoting GDP release and GTP binding. The Gα-GTP and Gβγ subunits then dissociate and go on to regulate downstream effectors such as adenylyl cyclase or phospholipase C, generating second messengers like cAMP, IP3, and DAG. Endosome trafficking is about receptor recycling and trafficking, not the main transduction path. Directly opening an ion channel isn’t the typical immediate mechanism for GPCRs; instead, channels are usually modulated by G-protein subunits. Phospholipase C can be activated downstream of G-proteins, but it still requires that initial G-protein signaling step. So the primary route is through the G-protein.

GPCRs convey signals by activating heterotrimeric G-proteins. When a ligand binds, the receptor changes shape and acts as a guanine nucleotide exchange factor for the Gα subunit, promoting GDP release and GTP binding. The Gα-GTP and Gβγ subunits then dissociate and go on to regulate downstream effectors such as adenylyl cyclase or phospholipase C, generating second messengers like cAMP, IP3, and DAG. Endosome trafficking is about receptor recycling and trafficking, not the main transduction path. Directly opening an ion channel isn’t the typical immediate mechanism for GPCRs; instead, channels are usually modulated by G-protein subunits. Phospholipase C can be activated downstream of G-proteins, but it still requires that initial G-protein signaling step. So the primary route is through the G-protein.

More practice questions