PDGFRA [C9]

The platelet-derived growth factor (PDGF) family consists of proteins derived from four genes (PDGF-α, -β, -C, and -D) that form disulfide-linked homodimers (PDGF-αα, -ββ, -CC, and -DD) and a heterodimer (PDGF-αβ). These proteins regulate diverse cellular functions by binding to and inducing the homo- or hetero-dimerization of two receptors (PDGFR alpha and beta). PDGFR-α can bind to both A and B subunits of PDGF, while PDGFR-β can only bind the B subunit. Ligand binding promotes either homo- or heterodimerization of the PDGF receptors in a specific manner. PDGF-αα induces the dimerization of two α receptors, PDGF-αβ induces dimerization of αα and αβ and PDGF-ββ induces the formation of three types of dimers, αα, αβ and ββ. Many cell types, including fibroblasts and smooth muscle cells, express both the alpha and beta receptors. It is expressed in primary and metastatic colon tumors and in normal colon tissue. Tumors may express a different isoform to that found in normal tissue.