OREXIN A (HCRT) Antibody – Sheep Polyclonal

This gene encodes a hypothalamic neuropeptide precursor protein that gives rise to two mature neuropeptides, orexin A and orexin B, by proteolytic processing. Orexin A and orexin B, which bind to orphan G-protein coupled receptors HCRTR1 and HCRTR2, function in the regulation of sleep and arousal. This neuropeptide arrangement may also play a role in feeding behavior, metabolism, and homeostasis. [provided by RefSeq, Jan 2010]

HCRT: 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 both OX1R and OX2R with a high affinity, whereas orexin-B binds only to OX2R with a similar high affinity. Defects in HCRT are the cause of narcolepsy type 1 (NRCLP1). Narcolepsy is a neurological disabling sleep disorder, characterized by excessive daytime sleepiness, sleep fragmentation, symptoms of abnormal rapid-eye-movement (REM) sleep, such as 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. 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. Belongs to the orexin family.

Protein type: Hormone

Chromosomal Location of Human Ortholog: 17q21

Cellular Component: synaptic vesicle; rough endoplasmic reticulum; perinuclear region of cytoplasm; extracellular region; cell junction; secretory granule

Molecular Function: type 2 hypocretin receptor binding; type 1 hypocretin receptor binding

Biological Process: synaptic transmission; elevation of cytosolic calcium ion concentration; negative regulation of transmission of nerve impulse; negative regulation of DNA replication; eating behavior; neuropeptide signaling pathway; negative regulation of potassium ion transport; protein kinase C activation; regulation of neurotransmitter secretion; G-protein signaling, coupled to IP3 second messenger (phospholipase C activating); positive regulation of calcium ion transport; regulation of excitatory postsynaptic membrane potential; positive regulation of transmission of nerve impulse

Disease: Narcolepsy 1