Galanin receptor 1 (IPR003906)
Short name: GAL1_rcpt
Overlapping homologous superfamilies
Galanin is involved in a variety of physiological mechanisms and disease states, from appetite and neuroregeneration to seizures and pain [PMID: 17604107, PMID: 16052044]. The actions of galanin are mediated through interaction with specific membrane receptors. Three receptor subtypes have been identified; Galanin receptor 1 (GALR1), Galanin receptor 2 (GALR2) and Galanin receptor 3 (GAL3), all of which are rhodopsin-like GPCRs. They differ from one another in terms of their expression patterns, affinity for various peptide analogues and G protein-coupling specificity [PMID: 9578554, PMID: 8750821, PMID: 10689365]. In signaling, all can act via the Gi/o class [PMID: 9126874], whilst GAL2 also has Gq/11 as a major signaling route [PMID: 7682064].
Galanin receptors are widely distributed in a wide range of central nervous system (CNS), peripheral tissues and in the endocrine, mirroring the distribution of galanin [PMID: 2417156, PMID: 10619483]. Galanin receptors mediate a variety of physiological functions including inhibition of glucose-induced insulin secretion [PMID: 15670772], stimulation of growth hormone release [PMID: 1281259] and modulation of gastrointestinal motility [PMID: 8734340]. These receptors also modulate neuronal functions including memory, nociception, spinal reflexes and feeding [PMID: 10619483, PMID: 12769595]. Disruption of galanin expression or galanin receptor signaling is seen in many multifactoral conditions, suggesting a role in the development and/or pathology of certain diseases. These include Alzheimer's disease, epilepsy, diabetes, alcoholism, neuropathic pain and cancer [PMID: 23233848, PMID: 2463283, PMID: 2471574].
This entry represents the galanin receptor 1 subtype, which is expressed at significant levels in regions of the brain and spinal cord including the hypothalamus, amygdala, hippocampus, thalamus and brainstem. It has also been detected throughout the length of the human gastro-intestinal tract [PMID: 7524088, PMID: 8670213, PMID: 8750821, PMID: 10689365]. Galanin receptor 1 reduces the concentration of cAMP [PMID: 7524088], opens G protein-coupled, inwardly rectifying K+ channels [PMID: 9722565], and stimulates MAP kinase activity [PMID: 9578554] in a manner that is sensitive to pertussis toxin.
GO:0004966 galanin receptor activity
GO:0016021 integral component of membrane