Maintaining a low concentration of calcium within cells is vital to their survival and this is achieved by calcium pumps
on the plasma membrane.
The researchers' starting point was the calcium pump located in the cell membrane of the model plant thale cress (Arabidopsis thaliana), but the regulatory mechanism also applies to the corresponding calcium pump in humans and animals.
When there are many calcium ions in a cell, some of these bind to calmodulin, which is thereby able to activate the calcium pump.
As the heart ages, these free radicals can greatly alter how well the cellular calcium pumps on the sarcoplasmic reticulum work.
In the aging heart, free radicals damage proteins, membranes, and calcium pumps on the sarcoplasmic reticulum that myocytes need to produce contractions.
Certain proteins, such as the calcium pump
protein and the contractile protein myosin, appear to change with age which may account for some alterations in the function of the aging heart.
The key role played by calcium pumps
in controlling of cytoplasmic calcium ions, regulation of calcium pump
activity will have profound effects on calcium signaling (12).
Samuel Denmeade at Johns Hopkins University in Baltimore, Maryland, and colleagues have spent 15 years engineering an analogue of thapsigargin, the plant's active ingredient, which works by shutting down essential calcium pumps
Furthermore, impairments in the calcium sequestration and extrusion pumps of either the ER (SERCA pumps) or the plasma membrane energy-dependent calcium pumps
(PMCA) have reduced activity in aged neurons.
European, American, and Australian researchers in a number of medical specialties, prominently pharmacology, discuss such aspects as fluorescent indicators, genetically encoded fluorescent calcium indicator proteins, calcium signaling networks in yeast, methods for studying calcium pumps
, apoptosis, and calcium entry channels and drug discovery.
Historically, SPCA2 were assumed to be redundant and less essential versions of better-known calcium pumps
that scavenge calcium inside of cells everywhere in the body and store it away.