GPCR (G protein-coupled receptors)

G protein-coupled receptors (GPCRs) are a large family of proteins found on cell surfaces that act as communication gateways. They detect signals such as hormones, neurotransmitters, and environmental stimuli, then transmit this information inside the cell to trigger specific responses. When a signaling molecule binds to a GPCR, it activates internal proteins called G proteins, which initiate various cellular processes. GPCRs are crucial for functions like vision, taste, mood regulation, and immune responses. They are also key targets for many medications used to treat conditions like allergies, hypertension, and depression.