Plasma Membrane Calcium Pump Dynamics and Regulation

The plasma membrane calcium pump (PMCA) is an essential ATP-driven enzyme that extrudes Ca2+ from the cytosol to maintain low resting intracellular Ca2+ levels. Four major isoforms display distinct tissue distributions and kinetic properties, enabling fine-tuned control of both global Ca2+ homeostasis and local microdomain signalling. The pump operates through alternating E1 and E2 conformational states, binding two Ca2+ ions in its high-affinity E1 state and releasing them to the extracellular space upon ATP hydrolysis. Autoinhibition by the C-terminal tail is relieved by calmodulin binding, while phosphorylation, proteolytic cleavage and the local lipid environment further modulate activity. Interaction with single-pass subunits such as neuroplastin or basigin enhances stability and transport efficiency. PMCA activity underpins a host of physiological processes—from synaptic plasticity and auditory transduction to cardiac contractility and cell survival—while dysregulation contributes to pathologies including neurodegeneration, ataxia and heart failure. Recent advances have elucidated the structural basis for pump regulation, the integration of PMCA into signalling complexes, and the metabolic pathways that sustain its function under stress, highlighting its potential as a therapeutic target.

Research from Nature Portfolio

Recent work has revealed the cryo-electron microscopy structure of human PMCA1 bound to its obligatory subunit neuroplastin, providing a 3.9 Å-resolution view of the transmembrane and cytoplasmic domains. This study delineated the subunit interface that stabilises the open cytoplasmic pathway for Ca2+ entry and clarifies mechanistic parallels with sarco/ endoplasmic reticulum Ca2+-ATPases. Another investigation employing neuron-specific deletion of neuroplastin demonstrated that loss of this subunit sharply reduces PMCA paralog expression in glutamatergic cells, leading to elevated intracellular Ca2+, altered circuit activity and impaired cognition. Together, these findings underscore the structural and functional indispensability of subunits in PMCA regulation and neuronal health.

Plasma Membrane Calcium Pump Dynamics and Regulation publication trend

The graph below shows the total number of articles in plasma membrane calcium pump dynamics and regulation across all publications each year (not limited to Nature Index journals).

Technical terms

PMCA (Plasma Membrane Ca2+-ATPase): An ATP-dependent pump that exports Ca2+ from the cytosol across the plasma membrane to maintain low resting intracellular Ca2+.

Neuroplastin: A single-pass transmembrane subunit that interacts with PMCAs to enhance their stability and Ca2+ transport efficiency.

Calmodulin: A Ca2+-binding regulatory protein that relieves autoinhibition of PMCA, increasing its activity upon rises in intracellular Ca2+.

Cryo-electron microscopy (cryo-EM): A structural biology technique allowing high-resolution imaging of membrane protein complexes in near-native states.

Ca2+ microdomains: Localised regions of elevated Ca2+ concentration within cells, crucial for precise regulation of signalling pathways.

References

1. Metabolic regulation of the PMCA: Role in cell death and survival. Cell Calcium (2017).
2. Structure of the human plasma membrane Ca2+-ATPase 1 in complex with its obligatory subunit neuroplastin. Nature Communications (2018).
3. Neuroplastin deletion in glutamatergic neurons impairs selective brain functions and calcium regulation: implication for cognitive deterioration. Scientific Reports (2017).
4. The Plasma Membrane Calcium Pump: New Ways to Look at an Old Enzyme. Journal of Biological Chemistry (2014).
5. Tissue Distribution of the Four Gene Products of the Plasma Membrane Ca2+ Pump A STUDY USING SPECIFIC ANTIBODIES*. Journal of Biological Chemistry (1995).
6. Identification and primary structure of a calmodulin binding domain of the Ca2+ pump of human erythrocytes.. Journal of Biological Chemistry (1988).
7. Plasma Membrane Calcium Pump (PMCA4)-Neuronal Nitric-oxide Synthase Complex Regulates Cardiac Contractility through Modulation of a Compartmentalized Cyclic Nucleotide Microdomain*. Journal of Biological Chemistry (2011).