Regulation of axon growth by the JIP1-AKT axis

J Cell Sci. 2014 Jan 1;127(Pt 1):230-9. doi: 10.1242/jcs.137208. Epub 2013 Nov 6.

Abstract

The polarisation of developing neurons to form axons and dendrites is required for the establishment of neuronal connections leading to proper brain function. The protein kinase AKT and the MAP kinase scaffold protein JNK-interacting protein-1 (JIP1) are important regulators of axon formation. Here we report that JIP1 and AKT colocalise in axonal growth cones of cortical neurons and collaborate to promote axon growth. The loss of AKT protein from the growth cone results in the degradation of JIP1 by the proteasome, and the loss of JIP1 promotes a similar fate for AKT. Reduced protein levels of both JIP1 and AKT in the growth cone can be induced by glutamate and this coincides with reduced axon growth, which can be rescued by a stabilized mutant of JIP1 that rescues AKT protein levels. Taken together, our data reveal a collaborative relationship between JIP1 and AKT that is required for axon growth and can be regulated by changes in neuronal activity.

Keywords: AKT; Axon; JIP1; Proteasome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • Cerebral Cortex / cytology
  • Cerebral Cortex / growth & development
  • Cerebral Cortex / metabolism*
  • Embryo, Mammalian
  • Gene Expression Regulation, Developmental*
  • Glutamic Acid / pharmacology
  • Growth Cones / drug effects
  • Growth Cones / metabolism*
  • Growth Cones / ultrastructure
  • Mice
  • Mice, Inbred C57BL
  • Primary Cell Culture
  • Proteasome Endopeptidase Complex / metabolism
  • Proteolysis
  • Proto-Oncogene Proteins c-akt / genetics*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction

Substances

  • Adaptor Proteins, Signal Transducing
  • Mapk8ip protein, mouse
  • Glutamic Acid
  • Proto-Oncogene Proteins c-akt
  • Proteasome Endopeptidase Complex