| Title : Sperm-Induced Ca(2+) Release in Mammalian Eggs: The Roles of PLCzeta, InsP(3), and ATP - Swann_2023_Cells_12_ |
| Author(s) : Swann K |
| Ref : Cells , 12 : , 2023 |
| Abstract : Mammalian egg activation at fertilization is triggered by a long-lasting series of increases in cytosolic Ca(2+) concentration. These Ca(2+) oscillations are due to the production of InsP(3) within the egg and the subsequent release of Ca(2+) from the endoplasmic reticulum into the cytosol. The generation of InsP(3) is initiated by the diffusion of sperm-specific phospholipase Czeta1 (PLCzeta) into the egg after gamete fusion. PLCzeta enables a positive feedback loop of InsP(3) production and Ca(2+) release which then stimulates further InsP(3) production. Most cytosolic Ca(2+) increases in eggs at fertilization involve a fast Ca(2+) wave; however, due to the limited diffusion of InsP(3), this means that InsP(3) must be generated from an intracellular source rather than at the plasma membrane. All mammalian eggs studied generated Ca(2+) oscillations in response to PLCzeta, but the sensitivity of eggs to PLCzeta and to some other stimuli varies between species. This is illustrated by the finding that incubation in Sr(2+) medium stimulates Ca(2+) oscillations in mouse and rat eggs but not eggs from other mammalian species. This difference appears to be due to the sensitivity of the type 1 InsP(3) receptor (IP3R1). I suggest that ATP production from mitochondria modulates the sensitivity of the IP3R1 in a manner that could account for the differential sensitivity of eggs to stimuli that generate Ca(2+) oscillations. |
| ESTHER : Swann_2023_Cells_12_ |
| PubMedSearch : Swann_2023_Cells_12_ |
| PubMedID: 38132129 |