4ms3
Crystal structure of the extracellular domain of human GABA(B) receptor bound to the endogenous agonist GABACrystal structure of the extracellular domain of human GABA(B) receptor bound to the endogenous agonist GABA
Template:ABSTRACT PUBMED 24305054
FunctionFunction
[GABR1_HUMAN] Component of a heterodimeric G-protein coupled receptor for GABA, formed by GABBR1 and GABBR2. Within the heterodimeric GABA receptor, only GABBR1 seems to bind agonists, while GABBR2 mediates coupling to G proteins. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase. Signaling inhibits adenylate cyclase, stimulates phospholipase A2, activates potassium channels, inactivates voltage-dependent calcium-channels and modulates inositol phospholipid hydrolysis. Calcium is required for high affinity binding to GABA. Plays a critical role in the fine-tuning of inhibitory synaptic transmission. Pre-synaptic GABA receptor inhibits neurotransmitter release by down-regulating high-voltage activated calcium channels, whereas postsynaptic GABA receptor decreases neuronal excitability by activating a prominent inwardly rectifying potassium (Kir) conductance that underlies the late inhibitory postsynaptic potentials. Not only implicated in synaptic inhibition but also in hippocampal long-term potentiation, slow wave sleep, muscle relaxation and antinociception. Activated by (-)-baclofen, cgp27492 and blocked by phaclofen.[1] [2] [3] [4] Isoform 1E may regulate the formation of functional GABBR1/GABBR2 heterodimers by competing for GABBR2 binding. This could explain the observation that certain small molecule ligands exhibit differential affinity for central versus peripheral sites.[5] [6] [7] [8] [GABR2_HUMAN] Component of a heterodimeric G-protein coupled receptor for GABA, formed by GABBR1 and GABBR2. Within the heterodimeric GABA receptor, only GABBR1 seems to bind agonists, while GABBR2 mediates coupling to G proteins. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors, such as adenylate cyclase. Signaling inhibits adenylate cyclase, stimulates phospholipase A2, activates potassium channels, inactivates voltage-dependent calcium-channels and modulates inositol phospholipid hydrolysis. Plays a critical role in the fine-tuning of inhibitory synaptic transmission. Pre-synaptic GABA receptor inhibits neurotransmitter release by down-regulating high-voltage activated calcium channels, whereas postsynaptic GABA receptor decreases neuronal excitability by activating a prominent inwardly rectifying potassium (Kir) conductance that underlies the late inhibitory postsynaptic potentials. Not only implicated in synaptic inhibition but also in hippocampal long-term potentiation, slow wave sleep, muscle relaxation and antinociception.[9] [10] [11] [12]
About this StructureAbout this Structure
4ms3 is a 2 chain structure. Full crystallographic information is available from OCA.
ReferenceReference
- ↑ Geng Y, Bush M, Mosyak L, Wang F, Fan QR. Structural mechanism of ligand activation in human GABA(B) receptor. Nature. 2013 Dec 12;504(7479):254-9. doi: 10.1038/nature12725. Epub 2013 Dec 4. PMID:24305054 doi:http://dx.doi.org/10.1038/nature12725
- ↑ Kaupmann K, Schuler V, Mosbacher J, Bischoff S, Bittiger H, Heid J, Froestl W, Leonhard S, Pfaff T, Karschin A, Bettler B. Human gamma-aminobutyric acid type B receptors are differentially expressed and regulate inwardly rectifying K+ channels. Proc Natl Acad Sci U S A. 1998 Dec 8;95(25):14991-6. PMID:9844003
- ↑ White JH, Wise A, Main MJ, Green A, Fraser NJ, Disney GH, Barnes AA, Emson P, Foord SM, Marshall FH. Heterodimerization is required for the formation of a functional GABA(B) receptor. Nature. 1998 Dec 17;396(6712):679-82. PMID:9872316 doi:http://dx.doi.org/10.1038/25354
- ↑ Nomura R, Suzuki Y, Kakizuka A, Jingami H. Direct detection of the interaction between recombinant soluble extracellular regions in the heterodimeric metabotropic gamma-aminobutyric acid receptor. J Biol Chem. 2008 Feb 22;283(8):4665-73. doi: 10.1074/jbc.M705202200. Epub 2007, Dec 28. PMID:18165688 doi:http://dx.doi.org/10.1074/jbc.M705202200
- ↑ Geng Y, Xiong D, Mosyak L, Malito DL, Kniazeff J, Chen Y, Burmakina S, Quick M, Bush M, Javitch JA, Pin JP, Fan QR. Structure and functional interaction of the extracellular domain of human GABA(B) receptor GBR2. Nat Neurosci. 2012 Jun 3;15(7):970-8. doi: 10.1038/nn.3133. PMID:22660477 doi:10.1038/nn.3133
- ↑ Kaupmann K, Schuler V, Mosbacher J, Bischoff S, Bittiger H, Heid J, Froestl W, Leonhard S, Pfaff T, Karschin A, Bettler B. Human gamma-aminobutyric acid type B receptors are differentially expressed and regulate inwardly rectifying K+ channels. Proc Natl Acad Sci U S A. 1998 Dec 8;95(25):14991-6. PMID:9844003
- ↑ White JH, Wise A, Main MJ, Green A, Fraser NJ, Disney GH, Barnes AA, Emson P, Foord SM, Marshall FH. Heterodimerization is required for the formation of a functional GABA(B) receptor. Nature. 1998 Dec 17;396(6712):679-82. PMID:9872316 doi:http://dx.doi.org/10.1038/25354
- ↑ Nomura R, Suzuki Y, Kakizuka A, Jingami H. Direct detection of the interaction between recombinant soluble extracellular regions in the heterodimeric metabotropic gamma-aminobutyric acid receptor. J Biol Chem. 2008 Feb 22;283(8):4665-73. doi: 10.1074/jbc.M705202200. Epub 2007, Dec 28. PMID:18165688 doi:http://dx.doi.org/10.1074/jbc.M705202200
- ↑ Geng Y, Xiong D, Mosyak L, Malito DL, Kniazeff J, Chen Y, Burmakina S, Quick M, Bush M, Javitch JA, Pin JP, Fan QR. Structure and functional interaction of the extracellular domain of human GABA(B) receptor GBR2. Nat Neurosci. 2012 Jun 3;15(7):970-8. doi: 10.1038/nn.3133. PMID:22660477 doi:10.1038/nn.3133
- ↑ White JH, Wise A, Main MJ, Green A, Fraser NJ, Disney GH, Barnes AA, Emson P, Foord SM, Marshall FH. Heterodimerization is required for the formation of a functional GABA(B) receptor. Nature. 1998 Dec 17;396(6712):679-82. PMID:9872316 doi:http://dx.doi.org/10.1038/25354
- ↑ Martin SC, Russek SJ, Farb DH. Molecular identification of the human GABABR2: cell surface expression and coupling to adenylyl cyclase in the absence of GABABR1. Mol Cell Neurosci. 1999 Mar;13(3):180-91. PMID:10328880 doi:http://dx.doi.org/S1044-7431(99)90741-8
- ↑ Nomura R, Suzuki Y, Kakizuka A, Jingami H. Direct detection of the interaction between recombinant soluble extracellular regions in the heterodimeric metabotropic gamma-aminobutyric acid receptor. J Biol Chem. 2008 Feb 22;283(8):4665-73. doi: 10.1074/jbc.M705202200. Epub 2007, Dec 28. PMID:18165688 doi:http://dx.doi.org/10.1074/jbc.M705202200
- ↑ Geng Y, Xiong D, Mosyak L, Malito DL, Kniazeff J, Chen Y, Burmakina S, Quick M, Bush M, Javitch JA, Pin JP, Fan QR. Structure and functional interaction of the extracellular domain of human GABA(B) receptor GBR2. Nat Neurosci. 2012 Jun 3;15(7):970-8. doi: 10.1038/nn.3133. PMID:22660477 doi:10.1038/nn.3133