Abstract
Orexin (also known as hypocretin) was discovered by reverse pharmacology as an endogenous ligand for two orphan G protein-coupled receptors in 1998. Orexin exists in two molecular forms, orexin-A and orexin-B, derived from the same 130-aa residue precursor (prepro-orexin). Orexin-A is a 33-aa residue peptide with two intrachain disulfide bonds that are fully conserved among tetrapods. Orexin-B is a linear 28-aa residue peptide. Orexin specifically binds to orexin receptors OX1R and OX2R. Orexin-A binds to OX1R and OX2R with a high affinity, whereas orexin-B selectively binds to OX2R with a similar high affinity. Orexin systems have roles in regulating feeding and drinking behavior, metabolism, the sleep-wake cycle, and the endocrine system.
| Original language | English |
|---|---|
| Title of host publication | Handbook of Hormones |
| Subtitle of host publication | Comparative Endocrinology for Basic and Clinical Research |
| Publisher | Elsevier |
| Pages | 133-135 |
| Number of pages | 3 |
| ISBN (Electronic) | 9780128206492 |
| DOIs | |
| State | Published - 2021/01/01 |
Keywords
- Appetite
- GPCR
- Hypocretin
- Metabolism
- Narcolepsy
- OX1R
- OX2R
- Sleep-wake cycle
ASJC Scopus subject areas
- General Medicine