title: [Calcium signaling in platelet activation].
abstract: The activation of platelet is the initial factor for natural hemostasis and thrombosis and the elevation in intracellular free calcium concentration ([Ca2+]i) plays a key role in platelet activation. The increased [Ca2+]i is due to the entry of extracellular Ca2+ through the plasma membrane (PM) and the release of intracellular Ca2+ through Ca2+ pools, which are divided mainly into two types: one is the dense tubular system (DTS), and the other is lysosome-like acidic organelles (LLAO). The former releases calciums via the signal transduction pathway of inositol-1,4,5-trisphosphate (IP3), and the latter via nicotinic acid adenine dinucleotide phosphate (NAADP). Sequentially, store-operated calcium channels (SOCC) are responsible for most of calcium influx from extracellular compartment, which is regulated by the cooperation of stromal interaction molecule 1 (STIM1), a Ca2+ sensor molecule in intracellular stores, and ORAI calcium release-activated calcium modulator 1 (Orail), a plasma membrane protein. Their regulation will emplify the results of elevation of [Ca2+]i. There are two different pumps to remove the intracellular free Ca2+ after the elevation of [Ca2+]i, one is sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA) to pump Ca2+ back to the intracellular stores, the other is the plasma membrane Ca2+ ATPase (PMCA) which pumps Ca2+ out of the cells, to maintain low intracellular calcium concentration relatively in the resting.
authors.affiliation: Laboratory of Cell Imaging, Henan University of Traditional Chinese Medicine, Zhengzhou.
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
mesh_terms: D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D009249:NADP / Q000031:analogs & derivatives / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D000071740:ORAI1 Protein; D015539:Platelet Activation / Q000502:physiology*; D000071737:Stromal Interaction Molecule 1
chemical_list: D015220:Calcium Channels; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D009249:NADP; C024376:NAADP; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium