Receptor for secretin (SCT), which is involved in different processes such as regulation of the pH of the duodenal content, food intake and water homeostasis (PubMed:20927047, PubMed:24273196, PubMed:30449620). The activity of this receptor is mediated by G proteins which activate adenylyl cyclase (PubMed:30449620). Upon binding to secretin, regulates the pH of the duodenum by (1) inhibiting the secretion of gastric acid from the parietal cells of the stomach and (2) stimulating the production of bicarbonate (NaHCO(3)) from the ductal cells of the pancreas (By similarity). In addition to regulating the pH of the duodenal content, plays a central role in diet induced thermogenesis: acts as a non-sympathetic brown fat (BAT) activator mediating prandial thermogenesis, which consequentially induces satiation (PubMed:30449620). Mechanistically, secretin released by the gut after a meal binds to secretin receptor (SCTR) in brown adipocytes, activating brown fat thermogenesis by stimulating lipolysis, which is sensed in the brain and promotes satiation (PubMed:30449620). Also able to stimulate lipolysis in white adipocytes (PubMed:24273196). Also plays an important role in cellular osmoregulation by regulating renal water reabsorption (PubMed:17283064). Also plays a role in the central nervous system: required for synaptic plasticity (PubMed:17008357). In brain, expressed in the hippocampal CA1 region, the lower layer of cerebral cortex, the anterior olfactory nuclei, the anterior ventrolateral thalamus, the lateral region of hypothalamus, substantia nigra, tegmental area and central nucleus of the inferior colliculus, the ventral supramamillary nucleus and the cerebellum (PubMed:17008357). Expressed in brown adipocytes: expression predominates in mature brown adipocytes (at protein level) (PubMed:30449620). Phosphorylated on Ser and Thr residues at the cytoplasmic C-terminus by G protein-coupled receptor kinases (GRKs). Mice are overtly normal and fertile (PubMed:17008357). Mice however display impaired synaptic plasticity in the hippocampus: the number of dendritic spines in the CA1 hippocampal pyramidal cells is slightly reduced and mice show abnormal social behavior (PubMed:17008357). Mice are not hyperphagic and display normal food intake (PubMed:24769669). Following a 12 week high-fat diet, knockout mice gain significantly less weight and exhibit lower body fat content, possibly caused by reduced fat absorption in the intestine (PubMed:24769669). Mice also show mild polydipsia and polyuria; kidney display altered glomerular and tubular morphology (PubMed:17283064). Belongs to the G-protein coupled receptor 2 family.