These receptors are all transmembrane proteins, composed of a ligand-binding extracellular domain with cysteine-rich region, a transmembrane domain, and a cytoplasmic domain with predicted serine/threonine specificity. Type I receptors are essential for signaling; and type II receptors are required for binding ligands and for expression of type I receptors.
These receptors are all transmembrane proteins that have an extracellular ligand-binding domain containing cysteine residues, a transmembrane region, and a cytoplasmic domain with predicted serine/threonine phosphorylation sites. Type I receptors are essential for signaling; and type II receptors are needed for binding ligands and the expression of type I receptors.