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Function

Neuropeptides that play a significant role in the regulation of food intake and sleep-wakefulness, possibly by coordinating the complex behavioral and physiologic responses of these complementary homeostatic functions. A broader role in the homeostatic regulation of energy metabolism, autonomic function, hormonal balance and the regulation of body fluids, is also suggested.

Orexin-A

Binds to orexin receptors HCRTR1/OX1R and HCRTR2/OX2R with a high affinity (By similarity). Stimulates food intake (By similarity). Modulates pituitary luteinizing hormone secretion in an ovarian steroid-dependent manner (By similarity).

Orexin-B

Binds to orexin receptor HCRTR2/OX2R only (By similarity). Stimulates food intake (By similarity). Modulates pituitary luteinizing hormone secretion in an ovarian steroid-dependent manner (By similarity).

Involvement in disease

Narcolepsy 1

NRCLP1

Neurological disabling sleep disorder, characterized by excessive daytime sleepiness, sleep fragmentation, symptoms of abnormal rapid-eye-movement (REM) sleep, cataplexy, hypnagogic hallucinations, and sleep paralysis. Cataplexy is a sudden loss of muscle tone triggered by emotions, which is the most valuable clinical feature used to diagnose narcolepsy. Human narcolepsy is primarily a sporadically occurring disorder but familial clustering has been observed.

None

The disease is caused by variants affecting the gene represented in this entry. Human narcolepsy is associated with a deficient orexin system. Orexins are absent and/or greatly diminished in the brain and cerebrospinal fluid (CSF) of most narcoleptic patients.

Post-translational modifications

Specific enzymatic cleavages at paired basic residues yield the different active peptides.

Sequence similarities

Belongs to the orexin family.

Tissue specificity

Abundantly expressed in subthalamic nucleus but undetectable in other brain regions tested (hypothalamus was not tested) and in heart, placenta, lung, liver, skeletal muscle, kidney and pancreas.

Cellular localization

  • Rough endoplasmic reticulum
  • Cytoplasmic vesicle
  • Synapse
  • Associated with perikaryal rough endoplasmic reticulum as well as cytoplasmic large granular vesicles at synapses.

Alternative names

OX, PPORX, PPOX, HCRT, Hypocretin neuropeptide precursor, Hypocretin, Orexin precursor, Prepro-orexin, Preprohypocretin, Hcrt

Target type

Proteins

Primary research area

Neuroscience

Molecular weight

13363Da

We found 4 products in 1 category

Primary Antibodies

Target

Reactive species