Fig. 1.
(A). Schematics shows the current information on phosphorylation of neurofilament subunits (NF-L, NF-M and NF-H) by various protein kinases on the amino-terminal head and carboxyl-terminal tail domains. (B). A signal transduction cascade hypothesized to be involved in the phosphorylation of ‘KSP motifs’ on the NF-M/NF-H subunits. According to this hypothesis Ca+2 influx, growth factors (GF), extracellular matrix (ECM), myelin-associated glycoprotein (MAG) and stress (osmotic, UV) are proposed to activate MAP kinases (ERK1/2, SAPK) or Cdk5, which are known to phosphorylate NF-M/NF-H in vivo.