Reactome: A Curated Pathway Database

Elevation of cytosolic Ca2+ levels (R-HSA-139853) [Homo sapiens]


Activation of non- excitable cells involves the agonist-induced elevation of cytosolic Ca2+, an essential process for platelet activation. It occurs through Ca2+ release from intracellular stores and Ca2+ entry through the plasma membrane. Ca2+ store release involves phospholipase C (PLC)-mediated production of inositol-1,4,5-trisphosphate (IP3), which in turn stimulates IP3 receptor channels to release Ca2+ from intracellular stores. This is followed by Ca2+ entry into the cell through plasma membrane calcium channels, a process referred to as store-operated calcium entry (SOCE). Stromal interaction molecule 1 (STIM1), a Ca2+ sensor molecule in intracellular stores, and the four transmembrane channel protein Orai1 are the key players in platelet SOCE. Other major Ca2+ entry mechanisms are mediated by the direct receptor-operated calcium (ROC) channel, P2X1 and transient receptor potential channels (TRPCs).

Additional Information
Compartment cytosol
Cross References
Database Identifier
BioModels Database BIOMD0000000088
Literature References
pubMedId Title Journal Year
18308196 Intracellular calcium release from human platelets: different messengers for multiple stores Trends Cardiovasc Med 2008
19422456 Calcium signaling in platelets J Thromb Haemost 2009
17703229 Calcium signalling in lymphocyte activation and disease Nat Rev Immunol 2007