Arachidonic acid promotes phosphorylation of 5-lipoxygenase at Ser-271 by MAPK-activated protein kinase 2 (MK2)

J Biol Chem. 2002 Apr 26;277(17):14793-800. doi: 10.1074/jbc.M111945200. Epub 2002 Feb 13.


We demonstrated previously that 5-lipoxygenase (5-LO), a key enzyme in leukotriene biosynthesis, can be phosphorylated by p38 MAPK-regulated MAPKAP kinases (MKs). Here we show that mutation of Ser-271 to Ala in 5-LO abolished MK2 catalyzed phosphorylation and clearly reduced phosphorylation by kinases prepared from stimulated polymorphonuclear leukocytes and Mono Mac 6 cells. Compared with heat shock protein 27 (Hsp-27), 5-LO was a weak substrate for MK2. However, the addition of unsaturated fatty acids (i.e. arachidonate 1-50 microm) up-regulated phosphorylation of 5-LO, but not of Hsp-27, by active MK2 in vitro, resulting in a similar phosphorylation as for Hsp-27. 5-LO was phosphorylated also by other serine/threonine kinases recognizing the motif Arg-Xaa-Xaa-Ser (protein kinase A, Ca(2+)/calmodulin-dependent kinase II), but these activities were not increased by fatty acids. HeLa cells expressing wild type 5-LO or S271A-5-LO, showed prominent 5-LO activity when incubated with Ca(2+)-ionophore plus arachidonate. However, when stimulated with only exogenous arachidonic acid, activity for the S271A mutant was significantly lower as compared with wild type 5-LO. It appears that phosphorylation at Ser-271 is more important for 5-LO activity induced by a stimulus that does not prominently increase intracellular Ca(2+) and that arachidonic acid stimulates leukotriene biosynthesis also by promoting this MK2-catalyzed phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arachidonate 5-Lipoxygenase / chemistry
  • Arachidonate 5-Lipoxygenase / genetics
  • Arachidonate 5-Lipoxygenase / metabolism*
  • Arachidonic Acid / physiology*
  • Calcium / metabolism
  • Enzyme Activation
  • HeLa Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Mitogen-Activated Protein Kinases / metabolism*
  • Mutagenesis, Site-Directed
  • Neutrophils / enzymology
  • Neutrophils / metabolism
  • Phosphorylation
  • Protein Kinases*
  • Protein Serine-Threonine Kinases
  • Protein Transport
  • Serine / metabolism*


  • Intracellular Signaling Peptides and Proteins
  • Arachidonic Acid
  • Serine
  • Arachidonate 5-Lipoxygenase
  • Protein Kinases
  • MAP-kinase-activated kinase 2
  • Protein Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinases
  • Calcium