Abstract
Activation of a variety of cell surface receptors results in the phospholipase C-catalyzed hydrolysis of the minor plasma membrane phospholipid phosphatidylinositol 4,5-bisphosphate, with concomitant formation of inositol 1,4,5-trisphosphate and diacylglycerol. There is strong evidence that inositol 1,4,5-trisphosphate stimulates Ca2+ release from intracellular stores. The Ca2+-releasing actions of inositol 1,4,5-trisphosphate are terminated by its metabolism through two distinct pathways. Inositol 1,4,5-trisphosphate is dephosphorylated by a 5-phosphatase to inositol 1,4-bisphosphate; alternatively, inositol 1,4,5-trisphosphate can also be phosphorylated to inositol 1,3,4,5-tetrakisphosphate by a 3-kinase. Although the mechanism of Ca2+ mobilization is understood, the precise mechanisms involved in Ca2+ entry are not known; the proposal that inositol 1,4,5-trisphosphate secondarily elicits Ca2+ entry by emptying an intracellular Ca2+ pool is considered.
| Original language | English |
|---|---|
| Journal | F A S E B Journal |
| Volume | 3 |
| Issue number | 8 |
| Pages (from-to) | 1899-905 |
| Number of pages | 7 |
| ISSN | 0892-6638 |
| Publication status | Published - 1989 |
| Externally published | Yes |
Keywords
- Animals
- Calcium
- Calcium Channels
- Cell Membrane
- Humans
- Inositol 1,4,5-Trisphosphate
- Inositol 1,4,5-Trisphosphate Receptors
- Inositol Phosphates
- Phosphorylation
- Receptors, Cell Surface
- Receptors, Cytoplasmic and Nuclear
- Signal Transduction
- Sugar Phosphates
- Type C Phospholipases