Receptor for somatostatin-14 and -28. This receptor is coupled via pertussis toxin sensitive G proteins to inhibition of adenylyl cyclase. Homodimer and heterodimer with SSTR2. Heterodimerization with SSTR2 inactivates SSTR3 receptor function. Internalized into endoplasmic vesicles upon somatostatin-stimulation. Densely expressed in cerebellum and at moderate levels in the amygdala, cortex, striatum, spleen, liver and pituitary. Phosphorylated. Phosphorylation increases upon somatostatin binding. Belongs to the G-protein coupled receptor 1 family.