The plasma membrane Ca2+ ATPase (PMCA) plays a major role in clearing Ca2+ from the neuronal cytoplasm. The cytoplasmic Ca2+ clearance rate affects neuronal excitability, synaptic plasticity, and neurotransmission. Here, we examined the modulation of PMCA activity by protein tyrosine kinases (PTKs) in hippocampal neurons. PMCA-mediated Ca2+ clearance slowed in the presence of PP2, an inhibitor of Src family kinases, and accelerated in the presence of C2-cermaide, an activator of PTKs. Ca2+ clearance kinetics were attenuated in cells expressing a dominant-negative Src mutant, suggesting that the pump is tonically stimulated by a PTK. Tonic stimulation was reduced in hippocampal neurons expressing shRNA directed to mRNA for Yes. shRNA-mediated knockdown of PMCA isoform 1 (PMCA1) removed tonic stimulation of Ca2+ clearance, indicating that the kinase stimulates PMCA1. Interleukin-1β (IL-1β) accelerated Ca2+ clearance in a manner blocked by an IL-1β receptor antagonist or by an inhibitor of neutral sphingomyelinase, the enzyme that produces ceramide. Thus, IL-1β activates a Src family kinase to stimulate the plasma membrane Ca2+ pump decreasing the duration of Ca2+ transients in hippocampal neurons.
- Ca2+ signaling
- Yes kinase
- Hippocampal neuron
- Copyright © 2015, Journal of Neurophysiology