Cdk5 and its substrates, Dcx and p27kip1, regulate cytoplasmic dilation formation and nuclear elongation in migrating neurons

Yoshiaki V. Nishimura, Mima Shikanai, Mikio Hoshino, Toshio Ohshima, Yo Ichi Nabeshima, Ken Ichi Mizutani, Koh Ichi Nagata, Kazunori Nakajima, Takeshi Kawauchi

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Neuronalmigration is crucial fordevelopment of themammalian-specific six-layered cerebral cortex. Migrating neurons are known to exhibit distinct features; they form a cytoplasmic dilation, a structure specific to migrating neurons, at the proximal region of the leading process, followed by nuclear elongation and forward movement. However, the molecular mechanisms of dilation formation and nuclear elongation remain unclear. Using ex vivo chemical inhibitor experiments, we show here that rottlerin, which is widely used as a specific inhibitor for PKCδ, suppresses the formation of a cytoplasmic dilation and nuclear elongation in cortical migrating neurons. Although our previous study showed that cortical neuronal migration depends on Jnk, another downstream target of rottlerin, Jnk inhibition disturbs only the nuclear elongation and forward movement, but not the dilation formation. We found that an unconventional cyclin-dependent kinase, Cdk5, is a novel downstream target of rottlerin, and that pharmacological or knockdown-mediated inhibition of Cdk5 suppresses both the dilation formation and nuclear elongation. We also show that Cdk5 inhibition perturbs endocytic trafficking as well as microtubule organization, both of which have been shown to be required for dilation formation. Furthermore, knockdown of Dcx, a Cdk5 substrate involved in microtubule organization and membrane trafficking, or p27kip1, another Cdk5 substrate involved in actin and microtubule organization, disturbs the dilation formation and nuclear elongation. These data suggest that Cdk5 and its substrates,Dcx and p27kip1, characterizemigratingneuronspecific features, cytoplasmic dilation formation and nuclear elongation in the mouse cerebral cortex, possibly through the regulation of microtubule organization and an endocytic pathway.

Original languageEnglish
Pages (from-to)3540-3550
Number of pages11
JournalDevelopment (Cambridge)
Volume141
Issue number18
DOIs
Publication statusPublished - 2014 Sep

Keywords

  • C-jun N-terminal kinase
  • Cdkn1b
  • Cell migration
  • Cytoskeleton
  • Doublecortin
  • Endocytosis
  • Mouse
  • Rab5

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology

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    Nishimura, Y. V., Shikanai, M., Hoshino, M., Ohshima, T., Nabeshima, Y. I., Mizutani, K. I., Nagata, K. I., Nakajima, K., & Kawauchi, T. (2014). Cdk5 and its substrates, Dcx and p27kip1, regulate cytoplasmic dilation formation and nuclear elongation in migrating neurons. Development (Cambridge), 141(18), 3540-3550. https://doi.org/10.1242/dev.111294