α<sub>1</sub>-Adrenergic receptor-PKC-Pyk2-Src signaling boosts L-type Ca<sup>2+</sup> channel Ca<sub>V</sub>1.2 activity and long-term potentiation in rodents.

Man, Kwun Nok Mimi; Bartels, Peter; Henderson, Peter B; Kim, Karam; Shi, Mei; Zhang, Mingxu; Ho, Sheng-Yang; Nieves-Cintron, Madeline et al. · Elife · 2023

basic_science · Level V

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Abstract

The cellular mechanisms mediating norepinephrine (NE) functions in brain to result in behaviors are unknown. We identified the L-type Ca<sup>2+</sup> channel (LTCC) Ca<sub>V</sub>1.2 as a principal target for G<sub>q</sub>-coupled α<sub>1</sub>-adrenergic receptors (ARs). α<sub>1</sub>AR signaling increased LTCC activity in hippocampal neurons. This regulation required protein kinase C (PKC)-mediated activation of the tyrosine kinases Pyk2 and, downstream, Src. Pyk2 and Src were associated with Ca<sub>V</sub>1.2. In model neuroendocrine PC12 cells, stimulation of PKC induced tyrosine phosphorylation of Ca<sub>V</sub>1.2, a modification abrogated by inhibition of Pyk2 and Src. Upregulation of LTCC activity by α<sub>1</sub>AR and formation of a signaling complex with PKC, Pyk2, and Src suggests that Ca<sub>V</sub>1.2 is a central conduit for signaling by NE. Indeed, a form of hippocampal long-term potentiation (LTP) in young mice requires both the LTCC and α<sub>1</sub>AR stimulation. Inhibition of Pyk2 and Src blocked this LTP, indicating that enhancement of Ca<sub>V</sub>1.2 activity via α<sub>1</sub>AR-Pyk2-Src signaling regulates synaptic strength.

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