OR1G1

Olfactory receptor 1G1 is a protein that in humans is encoded by the OR1G1 gene.

Function
Olfactory receptors interact with odorant molecules in the nose, to initiate a neuronal response that triggers the perception of a smell. The olfactory receptor proteins are members of a large family of G-protein-coupled receptors (GPCR) arising from single coding-exon genes. Olfactory receptors share a 7-transmembrane domain structure with many neurotransmitter and hormone receptors and are responsible for the recognition and G protein-mediated transduction of odorant signals. The olfactory receptor gene family is the largest in the genome. The nomenclature assigned to the olfactory receptor genes and proteins for this organism is independent of other organisms.

Ligands
The OR1G1 receptor is associated with sensory sensations including "waxy", "fatty", and "rose", and also "fruity" and "sweet".

Compared to other olfactory receptors such as OR52D1, OR1G1 is broadly tuned to respond to odorants in different chemical classes, but it is sensitive to chain length, responding most strongly to chains of 9-10 carbons.

Examples of agonists include:
 * nonanal (strong)
 * 1-nonanol (strong)
 * 2-ethyl-1-hexanol (strong)
 * γ-decalactone (strong)
 * ethyl isobutyrate (strong)
 * 1-octanol
 * celery ketone
 * citral
 * isoamyl acetate

Example antagonists include:
 * hexanal
 * 1-hexanol
 * cyclohexanone

The pattern of 6-carbon antagonists compared to ~9-carbon agonists is likely explained by OR1G1 having a deep pocket at its binding site, such that the 6-carbon molecules block the opening, but do not reach the bottom of the deep pocket as required to activate the signal transduction chain.