5-Hydroxytraptamine 1B Receptor

The serotonergic system is involved in both pathophysiology and treatment of addiction, depression or mood disorders, appetite control, cardiovascular function, motility of GI tract and sexual function.  Serotonin (5-HT) has long been implicated in a number of neurodevelopmental processes including neuronal cell division, migration, neurite outgrowth, and synapse formation which regulate and control some of the above physiological manifestations.  Molecular cloning of 5HT receptors have identified a family of closely related genes that encodes several proteins with extensive splice variants exhibiting high degree of amino acid homology (45%-65%) all in the molecular weight range of 40-60 kDa.  In brain the 5HT1A binding sites are tightly coupled to oestrous cycle and sex hormone levels (1).  Serotonin receptors, also known as 5HT receptors are G-protein coupled rectors (7 transmembrane domains) that elicit the serotonin mediated effects on the above diverse physiological functions.  There are at least 7 members of 5HT receptors (5HT1-5HT7), the 5HT1 is further divided in to 6 subtypes (5HT1A-5HT1F) each with multiple variants expressed as a results of alternate splicing or use of alternate initiation codons.  Serotonin is reabsorbed by serotonin reuptake transporter which is coupled to sodium/calcium pump. 

5HT1A receptors are grouped among the GPCR with characteristic 7TMD.  There are several variants isoform of the 5HT1A receptors (5HT1A-5HT1E).  The type if signal transduction could be excitatory or inhibitory depending upon the receptor functional coupling to the signal transduction complex.  Certain beta arrestins are co-localized with 5HT receptors, where they act in concert with Bark1 or GRK1 and GRK 2 to regulate the expression of the GPCRs.  All 5HT receptor proteins are glycosylated at or near the C-terminus and are present on either cell surface or in intracellular sites.  Some transporters exhibit dynamic trafficking between intracellular storage sites and plasma membranes in response to various stimuli.  5HT receptors are believed to be associated with other proteins including members of the dopamine receptors and opiod receptors resulting in a significant increase in their apparent molecular weight.   

For research use only, not for diagnostic or therapeutic use.