Role of activation of PIP5Kgamma661 by AP-2 complex in synaptic vesicle endocytosis

EMBO J. 2007 Feb 21;26(4):1105-16. doi: 10.1038/sj.emboj.7601573. Epub 2007 Feb 8.

Abstract

Synaptic vesicles (SVs) are retrieved by clathrin-mediated endocytosis at the nerve terminals. Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] drives this event by recruiting the components of the endocytic machinery. However, the molecular mechanisms that result in local generation of PI(4,5)P2 remain unclear. We demonstrate here that AP-2 complex directly interacts with phosphatidylinositol 4-phosphate 5-kinase gamma661 (PIP5Kgamma661), the major PI(4,5)P2-producing enzyme in the brain. The beta2 subunit of AP-2 was found to bind to the C-terminal tail of PIP5Kgamma661 and cause PIP5Kgamma661 activation. The interaction is regulated by PIP5Kgamma661 dephosphorylation, which is triggered by depolarization in mouse hippocampal neurons. Finally, overexpression of the PIP5Kgamma661 C-terminal region in hippocampal neurons suppresses depolarization-dependent SV endocytosis. These findings provide evidence for the molecular mechanism through which PIP5Kgamma661 locally generates PI(4,5)P2 in hippocampal neurons and suggest a model in which the interaction trigger SV endocytosis.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Protein Complex 2 / metabolism*
  • Animals
  • Endocytosis / physiology*
  • Enzyme Activation / physiology
  • Hippocampus / metabolism*
  • Immunohistochemistry
  • Mice
  • Models, Biological
  • Neurons / metabolism*
  • Phosphatidylinositol 4,5-Diphosphate / metabolism*
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Synaptic Vesicles / metabolism*
  • Synaptic Vesicles / physiology

Substances

  • Adaptor Protein Complex 2
  • Phosphatidylinositol 4,5-Diphosphate
  • Phosphotransferases (Alcohol Group Acceptor)
  • 1-phosphatidylinositol-4-phosphate 5-kinase