GABAB Receptor (Ser783), R2-Subunit (GABBR2) Antibody – Rabbit Polyclonal

Function: 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.2

Subunit structure: Heterodimer of GABBR1 and GABBR2. Homodimers may form, but are inactive. Interacts with ATF4 via its C-terminal region. Ref.2 Ref.5 Ref.6

Subcellular location: Cell membrane; Multi-pass membrane protein. Cell junction › synapse › postsynaptic cell membrane; Multi-pass membrane protein. Note: Coexpression of GABBR1 and GABBR2 is required for GABBR1 maturation and transport to the plasma membrane. In contrast, GABBR2 does not depend on GABBR1 for transport to the cell membrane. Ref.2

Tissue specificity: Expressed in brain cortex, hippocampus, medial habenula, thalamus and cerebellum. Coexpression is seen in cerebellum. Ref.2 Ref.3

Developmental stage: Abundant in brain cortex and cerebellum throughout postnatal development whereas its expression in spinal cord gradually decreases.

Domain: Alpha-helical parts of the C-terminal intracellular region mediate heterodimeric interaction with GABA-B receptor 1.

Sequence similarities: Belongs to the G-protein coupled receptor 3 family. GABA-B receptor subfamily.