GABAB receptor
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| Identifiers | |
| Symbol | GABBR1 |
| Entrez | 2550 |
| HUGO | 4070 |
| OMIM | 603540 |
| RefSeq | NM_021905 |
| UniProt | Q9UBS5 |
| Other data | |
| Locus | Chr. 6 p21.3 |
| Identifiers | |
| Symbol | GABBR2 |
| Alt. Symbols | GPR51 |
| Entrez | 9568 |
| HUGO | 4507 |
| OMIM | 607340 |
| RefSeq | NM_005458 |
| UniProt | O75899 |
| Other data | |
| Locus | Chr. 9 q22.1-22.3 |
- The correct title of this article is GABAB receptor. It features superscript or subscript characters that are substituted or omitted because of technical limitations.
GABAB receptors (GABABR) are metabotropic transmembrane receptors for gamma-aminobutyric acid (GABA) that are linked via G-proteins to potassium channels.[1] These receptors are found in the central and peripheral autonomic nervous system.[2]
Contents |
[edit] Functions
They can stimulate the opening of K+ channels which brings the neuron closer to the equilibrium potential of K+, hyperpolarising the neuron. This prevents sodium channels from opening, action potentials from firing, and VDCCs from opening, and so stops neurotransmitter release. Thus GABAB receptors are considered inhibitory receptors.
GABAB receptors can also reduce the activity of adenylyl cyclase and decrease the cell’s conductance to Ca2+.[2]
GABAB receptors are involved in behavioral actions of ethanol, [3] gamma-Hydroxybutyric acid (GHB),[4] and possibly in pain.[5] Recent research suggests that these receptors may play an important developmental role. [6]
[edit] Structure
GABABRs are similar in structure to and in the same receptor family with metabotropic glutamate receptors.[7] There are two subtypes of the receptor, GABAB1 and GABAB2,[8][2] and these appear to assemble as heterodimers in neuronal membranes by linking up by their intracellular C termini.[2][7]
It is speculated that binding of GABA causes the subunits to swing shut around the agonist like a venus fly trap.[2]
[edit] Agonists and antagonists
Baclofen is a GABA analogue which acts as a selective agonist of GABAB receptors, and is used as a muscle relaxant. However, it can aggravate absence seizures, and so is not used in epilepsy.
Saclofen, phaclofen and SCH-50911 are selective GABAB antagonists.
[edit] See also
[edit] References
- ^ Chen K, Li H, Ye N, Zhang J, Wang J (2005). "Role of GABAB receptors in GABA and baclofen-induced inhibition of adult rat cerebellar interpositus nucleus neurons in vitro". Brain Res Bull 67 (4): 310–8. doi:. PMID 16182939.
- ^ a b c d e Martin I.L., and Dunn S.M.J. 2002. GABA receptors Tocris Cookson Ltd.
- ^ Dzitoyeva S, Dimitrijevic N, Manev H (2003). "Gamma-aminobutyric acid B receptor 1 mediates behavior-impairing actions of alcohol in Drosophila: adult RNA interference and pharmacological evidence". Proc Natl Acad Sci U S A 100 (9): 5485–90. doi:. PMID 12692303.
- ^ Dimitrijevic N, Dzitoyeva S, Satta R, Imbesi M, Yildiz S, Manev H (2005). "Drosophila GABA(B) receptors are involved in behavioral effects of gamma-hydroxybutyric acid (GHB)". Eur J Pharmacol 519 (3): 246–52. doi:. PMID 16129424.
- ^ Manev H, Dimitrijevic N (2004). "Drosophila model for in vivo pharmacological analgesia research". Eur J Pharmacol 491 (2-3): 207–8. doi:. PMID 15140638.
- ^ Dzitoyeva S, Gutnov A, Imbesi M, Dimitrijevic N, Manev H (2005). "Developmental role of GABAB(1) receptors in Drosophila". Brain Res Dev Brain Res 158 (1-2): 111–4. doi:. PMID 16054235.
- ^ a b MRC (Medical Research Counsil). 2003. Glutamate receptors: Structures and functions. University of Brisotol Centre for Synaptic Plasticity.
- ^ Purves D., Augustine G.J., Fitzpatrick D., Katz L.C., LaMantia A.S., McNamara J.O., and Williams S.M. 2001. Neuroscience, Second Edition. Sinauer Associates, Inc.
