Platelet-derived growth factor
From Wikipedia, the free encyclopedia
Platelet-derived growth factor (PDGF) is one of the numerous proteins that regulate cell growth and division.
Contents |
[edit] Types/Classification
There are five different isoforms of PDGF that activate cellular response through two different receptors. Known ligands include A (PDGFA), B (PDGFB), C (PDGFC) and D (PDGFD) and an AB heterodimer and receptors alpha (PDGFRA) and beta(PDGFRB).
PDGFR is characterized as a tyrosine kinase receptor, providing a link to certain types of cancer. It is involved in the PI3K pathway. It has also been shown that the cis oncogene is derived from the PDGF B-chain gene. PDGF-BB is the highest-affinity ligand for the PDGFR-beta; PDGFR-beta is a key marker of hepatic stellate cell activation in the process of fibrogenesis.
[edit] Function
PDGF plays a role in embryonic development, cell proliferation, cell migration, and angiogenesis. PDGF has also been linked to several diseases such as atherosclerosis, fibrosis and malignant diseases.
[edit] History
PDGF was one of the first growth factors characterized, and has led to an understanding of the mechanism of many growth factor signaling pathways.
[edit] Structure
PDGF is known to exist as a dimer, and activates its signaling pathway by a ligand-induced receptor dimerization and autophosphorylation. PDGF receptors also contain many auto-phosphorylation sites, which serve to mediate binding of SH2 sites and subsequently signal corresponding pathways.
[edit] Clinical significance
Like many other growth factors that have been linked to disease, PDGF has provided a market for protein receptor antagonists to treat disease. Such antagonists usually include specific antibodies that target the molecule of interest, which only act in a neutralizing manner.
However, recent developments have allowed some biotechnology companies to circumvent this problem by creating specialized molecules that not only bind the protein of interest, but also destroy it in an enzymatic fashion.