• Source: 5-HT5A receptor

5-Hydroxytryptamine (serotonin) receptor 5A, also known as HTR5A, is a protein that in humans is encoded by the HTR5A gene. Agonists and antagonists for 5-HT receptors, as well as serotonin uptake inhibitors, present promnesic (memory-promoting) and/or anti-amnesic effects under different conditions, and 5-HT receptors are also associated with neural changes.




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 5-hydroxytryptamine and couples to 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. The 5-HT5A receptor has been shown to be functional in a native expression system.
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 a presynaptic serotonin autoreceptor.




Clinical significance


The neurotransmitter 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 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

=
LSD:(+)-lysergic acid.
Lisuride – partial agonist.
5-CT – full agonist.
Methylergometrine – full agonist.
Valerenic acid – a component of valerian, has been shown to act as a 5HT5A partial agonist.
Olanzapine – an atypical antipsychotic.
Psilocin
Aripiprazole - an atypical antipsychotic
Mirtazipine - an atypical antidepressant
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
MS112 – selective potent antangonist.
Latrepirdine (non-selective).
Risperidone – (non-selective), moderate 206 nM affinity.
SB-699,551




See also


5-HT receptor
5-HT1 receptor
5-HT2 receptor
5-HT3 receptor
5-HT4 receptor
5-HT6 receptor
5-HT7 receptor




References






Further reading






External links


"5-ht5a". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology.
Human HTR5A genome location and HTR5A gene details page in the UCSC Genome Browser.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.

Kata Kunci Pencarian:

• Reseptor serotonin
• 5-HT5A receptor
• 5-HT receptor
• Serotonin receptor agonist
• 5-HT2A receptor
• 5-HT2C receptor
• 5-HT2 receptor
• 5-HT6 receptor
• 5-HT3 receptor
• 5-HT4 receptor
• 5-Methoxytryptamine