The compartmentalization and translocation of the sphingosine kinases: mechanisms and functions in cell signaling and sphingolipid metabolism

Crit Rev Biochem Mol Biol. 2011 Oct;46(5):365-75. doi: 10.3109/10409238.2011.580097. Epub 2011 Aug 25.

Abstract

Members of the sphingosine kinase (SK) family of lipid signaling enzymes, comprising SK1 and SK2 in humans, are receiving considerable attention for their roles in a number of physiological and pathophysiological processes. The SKs are considered signaling enzymes based on their production of the potent lipid second messenger sphingosine-1-phosphate, which is the ligand for a family of five G-protein-linked receptors. Both SK1 and SK2 are intracellular enzymes and do not possess obvious membrane anchor domains within their primary sequences. The native substrates (sphingosine and dihydrosphingosine) are lipids, as are the corresponding products, and therefore would have a propensity to be membrane associated, suggesting that specific membrane localization of the SKs could affect both access to substrate and localized production of product. Here, we consider the emerging picture of the SKs as enzymes localized to specific intracellular sites, sometimes by agonist-dependent translocation, the mechanism targeting these enzymes to those sites, and the functional consequence of that localization. Not only is the signaling output of the SKs affected by subcellular localization, but the role of these enzymes as metabolic regulators of sphingolipid metabolism may be impacted as well.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Membrane / enzymology*
  • Cell Membrane / metabolism
  • Ceramides / metabolism
  • Humans
  • Lysophospholipids / metabolism
  • Mice
  • Phosphotransferases (Alcohol Group Acceptor) / chemistry
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Protein Transport
  • Signal Transduction
  • Sphingolipids / metabolism*
  • Sphingosine / analogs & derivatives
  • Sphingosine / metabolism
  • Substrate Specificity

Substances

  • Ceramides
  • Lysophospholipids
  • Protein Isoforms
  • Sphingolipids
  • sphingosine 1-phosphate
  • Phosphotransferases (Alcohol Group Acceptor)
  • sphingosine kinase
  • Sphingosine