Sandbox Reserved 970: Difference between revisions

There are 3 types of calcium ATPase depending on their localization. The '''SERCA''' (Sarco/Endoplasmic Reticulum Calcium ATPase) is localized in the endoplasmic reticulum membranes, including the nuclear envelope. Only the structure of the SERCA has been resolved by x-ray crystallography. The '''PMCA''' (Plasma Membrane Calcium ATPase) is localized in plasma membranes. The '''SPCA''' (Secretory Pathway Calcium ATPase) is localized in the Golgi apparatus membranes. The particularity of this pump is that it is also able to transport Mn2+ ions.  

Calcium is a very important molecule for cell signalling. Eucaryotic cells need to maintain a very low calcium concentration in their cytosol. The extracellular calcium concentration is much higher. That difference of concentrations across the membrane creates a gradient of concentration and allows the signalling to be very effective. Indeed, even a very small influx of calcium significantly increases the concentration of calcium inside the cell. Therefore, calcium pumps are very important to maintain the calcium concentration gradient and to remove calcium from the cell after signalling.