Voltage-gated calcium channel-Protein Kinase A signaling pathway (VGCC-PKA pathway)

The Voltage-gated calcium channel-Protein Kinase A (VGCC-PKA) signaling pathway in glutamatergic terminals is a fundamental regulatory mechanism for excitatory neurotransmission in the central nervous system. This pathway involves the activation of Protein Kinase A (PKA) via the cAMP second messenger system, which subsequently phosphorylates presynaptic voltage-gated calcium channels, specifically the N-type (Cav2.2) and P/Q-type (Cav2.1) channels (UniProt O00555, Q00975). Phosphorylation increases the open-probability and conductance of these channels, leading to enhanced calcium influx during neuronal depolarization and a corresponding increase in the release of glutamate into the synaptic cleft (Journal of Neuroscience, 2004). This mechanism is a key driver of synaptic plasticity and long-term potentiation, but its dysregulation is heavily implicated in pathological states such as chronic neuropathic pain and epilepsy, where it contributes to neuronal hyper-excitability (Nature Reviews Drug Discovery, 2007). Therapeutic interventions often target this pathway to dampen excessive glutamatergic signaling; for example, gabapentinoids bind to the alpha2-delta subunit of VGCCs to reduce channel trafficking, while opioids activate Gi/o-coupled receptors to inhibit adenylyl cyclase, thereby reducing PKA activity and subsequent calcium-dependent glutamate release (StatPearls, 2023).

Other names

Glutamatergic terminals / Ca2+ channel–PKA pathwayPresynaptic PKA-VGCC signalingcAMP-PKA-Ca2+ axisPKA-mediated glutamate release pathway

Modulation of presynaptic calcium influx through PKA-mediated phosphorylation of calcium channels to regulate the exocytosis of glutamate-containing vesicles.