Hypocretin (orexin) receptor 1
# Hypocretin (orexin) receptor 1

Orexin receptor type 1 (Ox1R or $OX_1),$ also known as hypocretin receptor type 1 (HcrtR1), is a protein that in humans is encoded by the HCRTR1 gene.

## Function

The orexin 1 receptor $(OX_1),$ is a G-protein coupled receptor that is heavily expressed in projections from the lateral hypothalamus and is involved in the regulation of feeding behaviour. $OX_1$ selectively binds the orexin-A neuropeptide. It shares 64% identity with $OX_2.$

## Ligands

### Agonists

* Orexin-A

### Antagonists

* RTIOX-276 - Selective $OX_1$ antagonist
* ACT-335827 - Selective $OX_1$ antagonist
* Almorexant - Dual $OX_1$ and $OX_2$ antagonist
* Lemborexant - Dual $OX_1$ and $OX_2$ antagonist
* Nemorexant - Dual $OX_1$ and $OX_2$ antagonist
* SB-334,867 - Selective $OX_1$ antagonist
* SB-408,124 - Selective $OX_1$ antagonist
* SB-649,868 - Dual $OX_1$ and $OX_2$ antagonist
* Suvorexant - Dual $OX_1$ and $OX_2$ antagonist
