A Push-Pull Mechanism Between PRRT2 and β4-subunit Differentially Regulates Membrane Exposure and Biophysical Properties of NaV1.2 Sodium Channels

Mol Neurobiol. 2023 Mar;60(3):1281-1296. doi: 10.1007/s12035-022-03112-x. Epub 2022 Nov 28.


Proline-rich transmembrane protein 2 (PRRT2) is a neuron-specific protein implicated in the control of neurotransmitter release and neural network stability. Accordingly, PRRT2 loss-of-function mutations associate with pleiotropic paroxysmal neurological disorders, including paroxysmal kinesigenic dyskinesia, episodic ataxia, benign familial infantile seizures, and hemiplegic migraine. PRRT2 is a negative modulator of the membrane exposure and biophysical properties of Na+ channels NaV1.2/NaV1.6 predominantly expressed in brain glutamatergic neurons. NaV channels form complexes with β-subunits that facilitate the membrane targeting and the activation of the α-subunits. The opposite effects of PRRT2 and β-subunits on NaV channels raises the question of whether PRRT2 and β-subunits interact or compete for common binding sites on the α-subunit, generating Na+ channel complexes with distinct functional properties. Using a heterologous expression system, we have observed that β-subunits and PRRT2 do not interact with each other and act as independent non-competitive modulators of NaV1.2 channel trafficking and biophysical properties. PRRT2 antagonizes the β4-induced increase in expression and functional activation of the transient and persistent NaV1.2 currents, without affecting resurgent current. The data indicate that β4-subunit and PRRT2 form a push-pull system that finely tunes the membrane expression and function of NaV channels and the intrinsic neuronal excitability.

Keywords: Intrinsic excitability; Persistent Na+ current; Proline-rich transmembrane protein 2; Resurgent Na+ current; Transient Na+ current.

MeSH terms

  • Ataxia
  • Brain
  • Humans
  • Membrane Proteins* / chemistry
  • Membrane Proteins* / metabolism
  • Mutation
  • NAV1.2 Voltage-Gated Sodium Channel* / chemistry
  • NAV1.2 Voltage-Gated Sodium Channel* / metabolism
  • Nerve Tissue Proteins* / chemistry
  • Nerve Tissue Proteins* / metabolism
  • Nervous System Diseases
  • Neurons* / chemistry
  • Neurons* / cytology


  • Membrane Proteins
  • Nerve Tissue Proteins
  • PRRT2 protein, human
  • NAV1.2 Voltage-Gated Sodium Channel