5-HT5A receptor

5-Hydroxytryptamine (serotonin) receptor 5A, also known as HTR5A, is a is_associated_with::protein that in humans is encoded by the HTR5A is_associated_with::gene.

Function
The gene described in this record is a member of 5-hydroxytryptamine receptor family and encodes a multi-pass membrane protein that functions as a receptor for is_associated_with::5-hydroxytryptamine and couples to is_associated_with::G proteins, negatively influencing cAMP levels via Gi and Go. This protein has been shown to function in part through the regulation of intracellular Ca2+ mobilization.

Rodents have been shown to possess two functional 5-HT5 receptor subtypes, 5-HT5A and 5-HT5B, however while humans possess a gene coding for the 5-HT5B subtype, its coding sequence is interrupted by stop codons, making the gene non-functional, and so only the 5-HT5A subtype is expressed in human brain.

It also appears to serve as an presynaptic serotonin autoreceptor.

Clinical significance
The neurotransmitter is_associated_with::serotonin (5-hydroxytryptamine, 5-HT) has been implicated in a wide range of psychiatric conditions and also has vasoconstrictive and vasodilatory effects.

Selective Ligands
Few highly selective ligands are commercially available for the 5-HT5A receptor. When selective activation of this receptor is desired in scientific research, the non-selective serotonin receptor agonist is_associated_with::5-Carboxamidotryptamine can be used in conjunction with selective antagonists for its other targets (principally 5-HT1A, 5-HT1B, 5-HT1D, and 5-HT7). Research in this area is ongoing.

Agonists

 * is_associated_with::Valerenic acid, a component of valerian, has been shown to act as a 5HT5A partial agonist.


 * Another ligand that has been recently disclosed is shown below, claimed be a selective 5-HT5A agonist with Ki = 124 nM.



Antagonists

 * ASP-5736
 * AS-2030680
 * AS-2674723
 * is_associated_with::Latrepirdine (non-selective)
 * is_associated_with::SB-699,551