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Orexin/Hypocretin Signaling

Jyrki P Kukkonen1

  • 1Biochemistry and Cell Biology, Department of Veterinary Biosciences, University of Helsinki, POB 66, FIN-00014, Helsinki, Finland. jyrki.kukkonen@helsinki.fi.

Current Topics in Behavioral Neurosciences
|December 3, 2016
PubMed

Insights

Orexin peptide signaling through OX1 and OX2 receptors shows diverse cellular responses. This diversity is observed across various cell types and species, highlighting complex signaling pathways.

Area of Science:

  • Neuroscience
  • Molecular Biology
  • Endocrinology

Background:

  • Orexin peptides (orexin-A and orexin-B) mediate their effects via two G-protein-coupled receptors (GPCRs): OX1 and OX2.
  • Previous research has explored orexin signaling in various endogenous and heterologous cell systems, including neurons and other cell types.

Purpose of the Study:

  • To present orexin signaling on cellular and molecular levels.
  • To discuss receptor signaling pathways across different tissues, cell types, and species.

Main Methods:

  • Investigation of orexin signaling in diverse endogenously orexin receptor-expressing cells (neurons and others).
  • Analysis of orexin signaling in recombinant cells expressing OX1 and OX2 receptors.
  • Comparative analysis of signaling pathways across different biological contexts.

Main Results:

  • Findings indicate partially convergent signaling patterns across different cell systems.
  • Evidence suggests significant cellular background-specific signaling, contributing to overall diversity.
  • A general picture of high diversity in orexin receptor signaling is presented.

Conclusions:

  • Orexin receptor signaling exhibits inherent complexity and diversity.
  • Understanding these diverse pathways is crucial for elucidating orexin's physiological roles.
Keywords:
Adenylyl cyclaseCalciumDiacylglycerol lipaseEndocannabinoidGiGqGsHeterotrimeric G-proteinHypocretinK+ channelNa+/Ca2+-exchangerNon-selective cation channelOX1 receptorOX2 receptorOrexinPhospholipase A2Phospholipase CPhospholipase DProtein kinase C

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