Phosphorylation of plant actin-depolymerising factor by calmodulin-like domain protein kinase

FEBS Lett. 2001 Jun 15;499(1-2):97-100. doi: 10.1016/s0014-5793(01)02528-5.


The actin-depolymerising factor (ADF)/cofilin group of proteins are stimulus-responsive actin-severing proteins, members of which are regulated by reversible phosphorylation. The phosphorylation site on the maize ADF, ZmADF3, is Ser-6 but the kinase responsible is unknown [Smertenko et al., Plant J. 14 (1998) 187-193]. We have partially purified the ADF kinase(s) and found it to be calcium-regulated and inhibited by N-(6-aminohexyl)-[(3)H]5-chloro-1-naphthalenesulphonamide. Immunoblotting reveals that calmodulin-like domain protein kinase(s) (CDPK) are enriched in the purified preparation and addition of anti-CDPK to in vitro phosphorylation assays results in the inhibition of ADF phosphorylation. These data strongly suggest that plant ADF is phosphorylated by CDPK(s), a class of protein kinases unique to plants and protozoa.

MeSH terms

  • Actin Depolymerizing Factors
  • Animals
  • Blotting, Western
  • Destrin
  • Enzyme Inhibitors / pharmacology
  • Fabaceae / enzymology*
  • Microfilament Proteins / metabolism*
  • Muscle, Skeletal
  • Phosphorylation / drug effects
  • Phosphoserine / metabolism
  • Plant Proteins*
  • Plants, Medicinal*
  • Protein Kinase Inhibitors
  • Protein Kinases / isolation & purification
  • Protein Kinases / metabolism*
  • Rabbits
  • Zea mays*


  • Actin Depolymerizing Factors
  • Destrin
  • Enzyme Inhibitors
  • Microfilament Proteins
  • Plant Proteins
  • Protein Kinase Inhibitors
  • Phosphoserine
  • Protein Kinases