Gamma-aminobutyric acid B receptor, 1 (GABA<sub>B1</sub>), is a G-protein coupled receptor subunit encoded by the GABBR1 gene.
GABA<sub>B1</sub> is a receptor for Gamma-aminobutyric acid. Upon binding, GABA<sub>B1</sub> will produce a slow and prolonged inhibitory effect. GABA<sub>B1</sub> is one part of a heterodimer, which is the GABA<sub>B</sub> receptor, consisting of it and the related GABA<sub>B2</sub> protein. The GABA(B) receptor 1 gene is mapped to chromosome 6p21.3 within the HLA class I region close to the HLA-F gene. Susceptibility loci for multiple sclerosis, epilepsy, and schizophrenia have also been mapped in this region. Alternative splicing of this gene generates 4 transcript variants.
GABBR1 has been shown to interact with ATF4 and GABBR2.