Molecular identification of albumin and Hsp70 as cytosolic anandamide-binding proteins

Chem Biol. 2009 Jun 26;16(6):624-32. doi: 10.1016/j.chembiol.2009.05.004. Epub 2009 May 29.

Abstract

The cellular uptake and the intracellular synthesis/degradation of anandamide are crucial steps for controlling its extracellular level and the duration of its activity. Although the biosynthesis and breakdown of anandamide are well understood, little is known about the mechanisms underlying its intracellular transport. Here, we investigated the presence of a potential carrier-mediated trafficking of anandamide within the cytosol, using a biotinylated analog as a tool to catch by affinity chromatography anandamide-interacting proteins. The identity of two of these anandamide-binding proteins, Hsp70 and serum albumin, was determined by mass spectrometry, confirmed by western blotting and confocal microscopy, and further validated through an anandamide-binding assay. These findings suggest that the trafficking of anandamide from the plasma membrane to the internal compartments of a cell occur via a nonvesicular mechanism mediated by cytosolic carriers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albumins / metabolism*
  • Amino Acid Sequence
  • Animals
  • Arachidonic Acids / chemistry
  • Arachidonic Acids / metabolism*
  • Biological Transport
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Cytosol / metabolism*
  • Endocannabinoids
  • HSP70 Heat-Shock Proteins / metabolism*
  • Humans
  • Mice
  • Polyunsaturated Alkamides / chemistry
  • Polyunsaturated Alkamides / metabolism*
  • Protein Binding

Substances

  • Albumins
  • Arachidonic Acids
  • Carrier Proteins
  • Endocannabinoids
  • HSP70 Heat-Shock Proteins
  • Polyunsaturated Alkamides
  • anandamide