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Valente P, Marte A, Franchi F, Sterlini B, Casagrande S, Corradi A, Baldelli P, Benfenati F. A Push-Pull Mechanism Between PRRT2 and β4-subunit Differentially Regulates Membrane Exposure and Biophysical Properties of NaV1.2 Sodium Channels. Mol Neurobiol 2023; 60:1281-1296. [PMID: 36441479 PMCID: PMC9899197 DOI: 10.1007/s12035-022-03112-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/26/2022] [Indexed: 11/29/2022]
Abstract
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.
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Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132, Genova, Italy. .,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Antonella Marte
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Francesca Franchi
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Silvia Casagrande
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Fabio Benfenati
- IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy. .,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy.
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