MST3 kinase phosphorylates TAO1/2 to enable Myosin Va function in promoting spine synapse development

Neuron. 2014 Dec 3;84(5):968-82. doi: 10.1016/j.neuron.2014.10.025. Epub 2014 Nov 13.

Abstract

Mammalian Sterile 20 (Ste20)-like kinase 3 (MST3) is a ubiquitously expressed kinase capable of enhancing axon outgrowth. Whether and how MST3 kinase signaling might regulate development of dendritic filopodia and spine synapses is unknown. Through shRNA-mediated depletion of MST3 and kinase-dead MST3 expression in developing hippocampal cultures, we found that MST3 is necessary for proper filopodia, dendritic spine, and excitatory synapse development. Knockdown of MST3 in layer 2/3 pyramidal neurons via in utero electroporation also reduced spine density in vivo. Using chemical genetics, we discovered thirteen candidate MST3 substrates and identified the phosphorylation sites. Among the identified MST3 substrates, TAO kinases regulate dendritic filopodia and spine development, similar to MST3. Furthermore, using stable isotope labeling by amino acids in culture (SILAC), we show that phosphorylated TAO1/2 associates with Myosin Va and is necessary for its dendritic localization, thus revealing a mechanism for excitatory synapse development in the mammalian CNS.

Publication types

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

MeSH terms

  • Age Factors
  • Animals
  • Cells, Cultured
  • Dendritic Spines / metabolism*
  • Embryo, Mammalian
  • Gene Expression Regulation, Developmental / genetics
  • Hippocampus / cytology
  • Humans
  • MAP Kinase Kinase Kinases / genetics
  • MAP Kinase Kinase Kinases / metabolism*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Mutation / genetics
  • Myosin Heavy Chains / metabolism*
  • Myosin Type V / metabolism*
  • Neurons / cytology*
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Rats
  • Rats, Long-Evans
  • Synapses / physiology*

Substances

  • MAP2 protein, rat
  • Microtubule-Associated Proteins
  • Myo5a protein, rat
  • RNA, Small Interfering
  • STK24 protein, human
  • Protein-Serine-Threonine Kinases
  • TAO1 protein kinase
  • Taok2 protein, rat
  • MAP Kinase Kinase Kinases
  • Myosin Type V
  • Myosin Heavy Chains