Final answer:
The activation of GTP-binding proteins like Gα in G-protein-coupled receptor signaling is initiated by guanine nucleotide exchange factors (GEFs) that stimulate the exchange of GDP for GTP.optiuon c is correct
Step-by-step explanation:
The activation of a GTP-binding protein, such as Gα, is a key step in the process of cell signaling via G-protein-coupled receptors (GPCRs). Among the options provided, the correct answer is C, which states that activation of an upstream guanine nucleotide exchange factor (GEF) is responsible for activating Gα.
GEFs facilitate the exchange of GDP for GTP on the G protein, activating it. Once activated, the Gα subunit can then go on to activate other cellular effectors, such as adenylyl cyclase, which converts ATP to cAMP and subsequently regulates various cellular functions.The activation of GTP-binding proteins like Gα in G-protein-coupled receptor signaling is initiated by guanine nucleotide exchange factors (GEFs) that stimulate the exchange of GDP for GTP.