kasvutekijäsignaaleja

Kasvutekijäsignaalit refer to the molecular signals that regulate cell growth, proliferation, differentiation, and survival. These signals are typically proteins, often secreted by cells, that bind to specific receptors on the surface of target cells. This binding event triggers a cascade of intracellular events, ultimately leading to a specific cellular response.

The process begins with the binding of a ligand, the growth factor, to its cognate receptor, which is usually a transmembrane protein. This binding often induces receptor dimerization or oligomerization, which activates the receptor's intracellular tyrosine kinase domain. The activated kinase then phosphorylates various intracellular proteins, including adaptor proteins and signaling molecules, initiating a signal transduction pathway.

Common signaling pathways activated by growth factors include the mitogen-activated protein kinase (MAPK) pathway, the phosphoinositide 3-kinase (PI3K)/Akt pathway, and the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. These pathways control fundamental cellular processes such as gene expression, protein synthesis, and cell cycle progression.

Dysregulation of growth factor signaling is implicated in various diseases, most notably cancer, where uncontrolled cell proliferation is a hallmark. Aberrant production of growth factors, mutations in growth factor receptors, or alterations in downstream signaling components can all contribute to tumorigenesis. Understanding these signaling pathways is crucial for developing targeted therapies for cancer and other diseases.