Which class of cell surface receptor is characterized by having seven transmembrane domains and is commonly involved in signal transduction via G proteins?

Recall the key features of the receptor types listed: (1) Ligand-gated ion channels are ion channels that open or close in response to ligand binding, but they do not have seven transmembrane domains. (2) G protein-coupled receptors (GPCRs) are known for their seven transmembrane domains and their role in signal transduction via G proteins. (3) Receptor tyrosine kinases (RTKs) are single-pass transmembrane proteins involved in phosphorylation cascades, not G protein signaling. (4) Nuclear hormone receptors are intracellular receptors, not cell surface receptors, and do not have transmembrane domains.