Switch-like PKA responses in the nucleus of striatal neurons

J Cell Sci. 2018 Jul 27;131(14):jcs216556. doi: 10.1242/jcs.216556.


Although it is known that protein kinase A (PKA) in the nucleus regulates gene expression, the specificities of nuclear PKA signaling remain poorly understood. Here, we combined computational modeling and live-cell imaging of PKA-dependent phosphorylation in mouse brain slices to investigate how transient dopamine signals are translated into nuclear PKA activity in cortical pyramidal neurons and striatal medium spiny neurons. We observed that the nuclear PKA signal in striatal neurons featured an ultrasensitive responsiveness, associated with fast all-or-none responses, which is not consistent with the commonly accepted theory of a slow and passive diffusion of catalytic PKA in the nucleus. Our numerical model suggests that a positive feed-forward mechanism inhibiting nuclear phosphatase activity - possibly mediated by DARPP-32 (also known as PPP1R1B) - could be responsible for this non-linear pattern of nuclear PKA response, allowing for a better detection of the transient dopamine signals that are often associated with reward-mediated learning.

Keywords: Biosensor imaging; Modeling; Nucleus; Protein kinase A; Signal integration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Nucleus / enzymology*
  • Cell Nucleus / genetics
  • Corpus Striatum / cytology
  • Corpus Striatum / enzymology*
  • Cyclic AMP-Dependent Protein Kinases / genetics
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • Dopamine / metabolism
  • Dopamine and cAMP-Regulated Phosphoprotein 32 / genetics
  • Dopamine and cAMP-Regulated Phosphoprotein 32 / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neurons / cytology
  • Neurons / enzymology*
  • Phosphorylation
  • Signal Transduction


  • Dopamine and cAMP-Regulated Phosphoprotein 32
  • Cyclic AMP-Dependent Protein Kinases
  • Dopamine