Characterization of a neurofilament-associated kinase that phosphorylates the middle molecular mass component of chicken neurofilaments

Brain Res. 1992 Dec 25;599(2):237-45. doi: 10.1016/0006-8993(92)90397-r.


We have examined the properties of a chicken neurofilament (NF) kinase partially purified from NF-enriched preparations. This kinase cosediments with NFs following extraction with Triton X-100 and can be separated in an active form from NFs by treatment with 0.8 M KCl. Sequential chromatography of the salt extract on DEAE-cellulose and phosphocellulose results in an approximately 500-fold increase in specific activity over endogenous NF preparations as measured by 32P-incorporation into the middle molecular mass component of NFs (NF-M). The kinase is Mg(2+)-dependent, second messenger-independent and inhibited by high concentrations of heparin. It shows selectivity for NF-M and evidence is presented that the kinase phosphorylates NF-M solely in the tail domain. The kinase can also phosphorylate the microtubule-associated proteins tau and MAP2 as well as mammalian NF-M, all of which share putative phosphorylation sequences with chicken NF-M.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chickens
  • Intermediate Filaments / enzymology*
  • Molecular Weight
  • Neurofilament Proteins / metabolism*
  • Phosphorylation
  • Protein Kinases / analysis*
  • Protein Kinases / metabolism
  • Substrate Specificity


  • Neurofilament Proteins
  • Protein Kinases