4ms3: Difference between revisions
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{{STRUCTURE_4ms3| PDB=4ms3 | SCENE= }} | |||
===Crystal structure of the extracellular domain of human GABA(B) receptor bound to the endogenous agonist GABA=== | |||
==Function== | |||
[[http://www.uniprot.org/uniprot/GABR1_HUMAN 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.<ref>PMID:9844003</ref> <ref>PMID:9872316</ref> <ref>PMID:18165688</ref> <ref>PMID:22660477</ref> 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.<ref>PMID:9844003</ref> <ref>PMID:9872316</ref> <ref>PMID:18165688</ref> <ref>PMID:22660477</ref> [[http://www.uniprot.org/uniprot/GABR2_HUMAN 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.<ref>PMID:9872316</ref> <ref>PMID:10328880</ref> <ref>PMID:18165688</ref> <ref>PMID:22660477</ref> | |||
==About this Structure== | |||
[[4ms3]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MS3 OCA]. | |||
==Reference== | |||
<references group="xtra"/><references/> | |||
[[Category: Bush, M.]] | |||
[[Category: Fan, Q R.]] | |||
[[Category: Geng, Y.]] | |||
[[Category: Mosyak, L.]] | |||
[[Category: Wang, F.]] | |||
[[Category: Heterodimeric protein complex]] | |||
[[Category: Neurotransmitter receptor]] | |||
[[Category: Signaling protein-agonist complex]] | |||
[[Category: Venus flytrap module]] | |||