High Calcium Pumps And Exchanger

1470 Words 6 Pages
Calcium is the richest mineral in our body holding many functions during the human development. Ca2+ controls many cellular processes such as: metabolism, gene transcription, fertilisation, proliferation, hypertrophy, secretion, exocytosis, cardiac ventricular mechanisms, neuronal dopaminergic pacemaker mechanisms, contraction, coordination and thinking, (Rubin, 2016). These processes can occur anywhere between a few microseconds to hours to complete. The basal Ca2+ concentration of approximately 100nM can rise above 500nM causing cell death, (Berridge, 2016). This rapid increase is caused by a stimulant that activates the signalling pathway and alters cellular processes. However, high Ca2+ concentration can be regulated through many mechanisms …show more content…
The process where Ca2+ returns to its basal level is called the recovery process. During this process, Ca2+ pumps and exchangers operate at different times. Several types of pumps and exchangers have various properties and locations within cells. The Na+/Ca2+ exchanger has low affinities, but high capacities for Ca2+ allowing it to act earlier during the recovery process to remove high levels of Ca2+ from within the cell. Alternatively, the plasma membrane Ca2+-ATPase (PMCA) and Sarco/endo-plasmic reticulum Ca2+-ATPase (SERCA) pumps, which require ATP, have lower capacities and higher affinities allowing the full completion of the recovery process to prevent cell alteration due to unstable Ca2+ …show more content…
Some of the effectors which are activated are: Ca2+ sensitive and potassium channels, Ca2+/calmodulin-dependent protein kinases, calcineurin and phosphorylase kinase. The Ca2+ sensitive and potassium channels are potassium channels either in the nucleus or cytoplasm which open and close in response to Ca2+. This channel regulates transmitter release, muscular contraction, excitation of neurons, up-regulation of gene expression, release of hormones and neurotransmitters (FABER and SAH, 2016). The Ca2+ calmodulin sensor activates effector Ca2+/calmodulin-dependent protein kinases(CaMKs) which are kinases themselves binding to one substrate. CaMKs are located in the nucleus. Many other CaMK kinase enzymes can phosphorylate many substrates. Calcium needs the CaM sensor to stimulate these effector kinases. CaMKs are involved in gene expression and activating transcription factors. CaMKs can act as molecular switches regulating the brain for learning and memory, allowing Ca2+ to trigger chromosome separation at the anaphase level. It also allows the activation of phosphatidylinositol 3- kinase during phagosome maturation by Ca2+. Calcineurin is also a Ca2+ sensitive enzyme part of the serine/threonine protein phosphatases (Bandyopadhyay, 2016). changes to this enzyme can cause brain defects and alteration in gene

Related Documents