A Ca(v)3.2/syntaxin-1A signaling complex controls T-type channel activity and low-threshold exocytosis.

Résumé : T-type calcium channels represent a key pathway for Ca(2+) entry near the resting membrane potential. Increasing evidence supports a unique role of these channels in fast and low-threshold exocytosis in an action potential-independent manner, but the underlying molecular mechanisms have remained unknown. Here, we report the existence of a syntaxin-1A/Ca(v)3.2 T-type calcium channel signaling complex that relies on molecular determinants that are distinct from the synaptic protein interaction site (synprint) found in synaptic high voltage-activated calcium channels. This interaction potently modulated Ca(v)3.2 channel activity, by reducing channel availability. Other members of the T-type calcium channel family were also regulated by syntaxin-1A, but to a smaller extent. Overexpression of Ca(v)3.2 channels in MPC 9/3L-AH chromaffin cells induced low-threshold secretion that could be prevented by uncoupling the channels from syntaxin-1A. Altogether, our findings provide compelling evidence for the existence of a syntaxin-1A/T-type Ca(2+) channel signaling complex and provide new insights into the molecular mechanism by which these channels control low-threshold exocytosis.
Type de document : Article dans des revues
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Contributeur : Canepari Marco <>
Soumis le : lundi 26 novembre 2012 - 17:00:32
Dernière modification le : lundi 26 novembre 2012 - 17:00:32


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Norbert Weiss, Shahid Hameed, José Fernández-Fernández, Katell Fablet, Maria Karmazinova, et al.. A Ca(v)3.2/syntaxin-1A signaling complex controls T-type channel activity and low-threshold exocytosis.. Journal of Biological Chemistry, American Society for Biochemistry and Molecular Biology, 2012, 287 (4), pp.2810-8. <10.1074/jbc.M111.290882>. <inserm-00757396>