Oxytocin stimulates a G protein-coupled signal transduction pathway. During signal transduction in this pathway, a G protein becomes activated. Which three molecules does G protein interact with in this pathway?

G protein-linked receptor, GTP, and effector protein

Explanation:

G protein coupled receptor is a seven trans-membrane protein, when ligand binds to the receptor, it activate the receptor which in turn activate the G protein. In inactive form, G protein binds to GDP, but when it become active, GDP is replaced by GTP. After activation the beta and gama sub-unit separates from the alpha sub-unit. Alpha sub-unit with bind GTP finally activates the effector protein, which then moves into the nucleus and activate or repress the transcription.