Growth signals operate through a series of molecular interactions beginning with the binding of a growth factor to its receptor. This binding activates the receptor's intrinsic kinase activity, leading to phosphorylation of specific tyrosine residues. The phosphorylated residues serve as docking sites for adaptor proteins and other signaling molecules, which propagate the signal downstream via various pathways such as the MAPK/ERK, PI3K/Akt, and JAK/STAT pathways. These pathways ultimately lead to changes in gene expression, protein synthesis, and cell cycle progression.
