5-Hydroxytryptamine 5B receptor (IPR000431)

Short name: 5HT5B_rcpt

Overlapping homologous superfamilies


Family relationships


5-hydroxytryptamine (5-HT) or serotonin, is a neurotransmitter that it is primarily found in the gastrointestinal (GI) tract, platelets, and in the central nervous system (CNS). It is implicated in a vast array of physiological and pathophysiological pathways. Receptors for 5-HT mediate both excitatory and inhibitory neurotransmission, and modulate the release of many neurotransmitters including glutamate, GABA, dopamine, epinephrine/norepinephrine, and acetylcholine, as well as many hormones, including oxytocin, prolactin, vasopressin and cortisol. In the CNS, 5-HT receptors can influence various neurological processes, such as aggression, anxiety and appetite and, as a, result are the target of a variety of pharmaceutical drugs, including many antidepressants, antipsychotics and anorectics [PMID: 18476671].

The 5-HT receptors are grouped into a number of distinct subtypes, classified according to their antagonist susceptibilities and their affinities for 5-HT. With the exception of the 5-HT3 receptor, which is a ligand-gated ion channel [PMID: 11989819], all 5-HT receptors are members of the rhodopsin-like G protein-coupled receptor family [PMID: 18476671], and they activate an intracellular second messenger cascade to produce their responses.

This entry represents the 5-HT5B receptor. As yet it has only been experimentally characterised in rodents, but not in humans [PMID: 8450829]. The 5HT5B protein has a structure consistent with GPCRs, however, the human 5-HT5B gene does not encode a functional protein, because its coding sequence is interrupted by stop codons [PMID: 11343685]. It is believed that the function of the 5HT5B receptor has been replaced in humans by some other subclass of 5-HT receptor [PMID: 11343685]. In the CNS, it is found in the habenula, hippocampus and inferior olivary of rat brains [PMID: 11295248, PMID: 7682702, PMID: 8450829]. Known agonists for 5-HT5B include ergotamine and LSD, and known antagonists include methiothepin. 5-HT5B receptors may play a role in sleep [PMID: 15921820] and serve as an presynaptic serotonin autoreceptor [PMID: 16846620].

GO terms

Biological Process

GO:0007186 G-protein coupled receptor signaling pathway

Molecular Function

GO:0004993 G-protein coupled serotonin receptor activity

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.