Final answer:
The RTK-mediated PI3K signaling pathway involves receptor tyrosine kinases (RTKs) and phosphatidylinositol 3-kinase (PI3K). When a growth factor binds to an RTK, it activates a signaling cascade that regulates cell growth, proliferation, and survival.
Step-by-step explanation:
The RTK-mediated PI3K signaling pathway is a cell signaling pathway that involves receptor tyrosine kinases (RTKs) and phosphatidylinositol 3-kinase (PI3K). When a growth factor binds to an RTK on the cell surface, it activates the RTK, which then phosphorylates itself and creates docking sites for signaling proteins. One of the signaling proteins recruited is PI3K, which phosphorylates the lipid phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 serves as a second messenger that initiates a signaling cascade, activating downstream effectors such as protein kinase B (AKT) and mammalian target of rapamycin (mTOR), which regulate various cellular processes, including cell growth, proliferation, and survival.