GHSR

G protein-coupled receptor specific to ghrelin, an appetite-regulating peptide hormone commonly found in stomach. Upon activation, stimulates appetite and promotes growth hormone secretion. Ghrelin binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as phospholipase C (By similarity). GHSR is coupled to G(q) G proteins and mediates production of diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) (By similarity). Also binds other growth hormone releasing peptides (GHRP) (e.g. Met-enkephalin and GHRP-6) as well as non-peptide, low molecular weight secretagogues (e.g. L-692, 429, MK-0677, adenosine). Also plays a role in synaptic plasticity independently of ghrelin by forming a heteromer with the dopamine receptors DRD1 and DRD2 in neurons (By similarity). Following DRD1 activation by dopamine in hippocampal neurons, GHSR acts as a coreceptor, resulting in DRD1 coupling to G(q) at the expense of G(s), initiating hippocampal synaptic plasticity involved in memory and learning (By similarity). Following DRD2 activation by dopamine in lumbosacral defecation centers, GHSR acts as a coreceptor, resulting in DRD1 coupling to G(q) at the expense of G(i)/G(o), regulating defecation (By similarity)..

Function from UniProtKB (Q92847), read 2026-09-23. CC BY 4.0.