Synaptic vesicle-associated Ca2+/calmodulin-dependent protein kinase II is a binding protein for synapsin I

Nature. 1992 Oct 1;359(6394):417-20. doi: 10.1038/359417a0.


Synapsin I is a synaptic vesicle-associated phosphoprotein that is involved in the modulation of neurotransmitter release. Ca2+/calmodulin-dependent protein kinase II, which phosphorylates two sites in the carboxy-terminal region of synapsin I, causes synapsin I to dissociate from synaptic vesicles and increases neurotransmitter release. Conversely, the dephosphorylated form of synapsin I, but not the form phosphorylated by Ca2+/calmodulin-dependent protein kinase II, inhibits neurotransmitter release. The amino-terminal region of synapsin I interacts with membrane phospholipids, whereas the C-terminal region binds to a protein component of synaptic vesicles. Here we demonstrate that the binding of the C-terminal region of synapsin I involves the regulatory domain of a synaptic vesicle-associated form of Ca2+/calmodulin-dependent protein kinase II. Our results indicate that this form of the kinase functions both as a binding protein for synapsin I, and as an enzyme that phosphorylates synapsin I and promotes its dissociation from the vesicles.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brain / enzymology
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Chromatography, High Pressure Liquid
  • Electrophoresis, Gel, Two-Dimensional
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression Regulation, Enzymologic*
  • Molecular Sequence Data
  • Phosphorylation
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Rats
  • Receptors, Neurotransmitter / metabolism
  • Substrate Specificity
  • Synapsins / metabolism*
  • Synaptic Vesicles / metabolism*


  • Receptors, Neurotransmitter
  • Synapsins
  • Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases

Grant support