Platelet-derived growth factor (PDGF) is one of the numerous proteins that regulate cell growth and division. There are five different isoforms of PDGF that activate through two different receptors. Known ligands include A, B, C and D and a AB heterodimer and receptors alpha and beta. PDGF plays a role in embryonic development, cell proliferation, migration, and angiogenesis. PDGF has also been linked to several diseases such as atherosclerosis, fibrosis and malignant diseases.
PDGFR is characterized as a tyrosine kinase receptor, providing a link to certain types of cancer. It has also been shown that the sis oncogene is derived from the PDGF B-chain gene.
PDGF was one of the first growth factors characterized, and has led to an understanding of the mechanism of many growth factor signaling pathways. 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.
Like many other growth factors that have been linked to disease, PDGF has provided a market for protein antagonists to treat disease. Such antagonists usually include specific antibodies that target the molecule of interest, which only act in a neutralizing manner. Although, 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.