title: Hypocretin (orexin) receptor 1
text: # 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
  