Site-specific Phosphorylation of neurofilament-L Is Mediated by calcium/calmodulin-dependent Protein Kinase II in the Apical Dendrites During Long-Term Potentiation

J Neurochem. 2000 Jul;75(1):373-82. doi: 10.1046/j.1471-4159.2000.0750373.x.

Abstract

Neurofilament-L (NF-L), one subunit of the neuronal intermediate filaments, is a major element of neuronal cytoskeletons. The dynamics of NF-L are regulated by phosphorylation of its head domain. The phosphorylation sites of the NF-L head domain by protein kinase A, protein kinase C, and Rho-associated kinase have been previously identified, and those by calcium/calmodulin-dependent protein kinase II (CaMKII) were identified in this study. A series of site- and phosphorylation state-specific antibodies against NF-L was prepared to investigate NF-L phosphorylation in neuronal systems. Long-term potentiation (LTP) is a cellular model of neuronal plasticity that is thought to involve the phosphorylation of various proteins. NF-L is considered a possible substrate for phosphorylation. During LTP stimulation of mouse hippocampal slices, the series of antibodies demonstrated the increase in the phosphorylation level of Ser(57) in NF-L and the visualization of the localized distribution of Ser(57) phosphorylation in a subpopulation of apical dendrites of the pyramidal neurons. Furthermore, Ser(57) phosphorylation during LTP is suggested to be mediated by CaMKII. Here we show that NF-L is phosphorylated by CaMKII in a subpopulation of apical dendrites during LTP, indicating that Ser(57) is a novel phosphorylation site of NF-L in vivo related to the neuronal signal transduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Calcimycin / pharmacology
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cattle
  • Dendrites / enzymology*
  • Ionophores / pharmacology
  • Long-Term Potentiation*
  • Male
  • Mice
  • Molecular Sequence Data
  • Neurofilament Proteins / chemistry
  • Neurofilament Proteins / metabolism*
  • Neuronal Plasticity
  • Neurons / ultrastructure*
  • Phosphorylation
  • Rats
  • Recombinant Proteins / metabolism
  • Sequence Homology

Substances

  • Ionophores
  • Neurofilament Proteins
  • Recombinant Proteins
  • neurofilament protein L
  • Calcimycin
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • Calcium-Calmodulin-Dependent Protein Kinases