Tyrosine-protein kinase that acts as a cell-surface receptor for pdgfa, pdgfb and pdgfc and plays an essential role in the regulation of embryonic development, cell proliferation, survival and chemotaxis. Depending on the context, promotes or inhibits cell proliferation and cell migration. Plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells. Required for normal skeleton development. Required for normal development of the gastrointestinal tract. Plays a role in cell migration and chemotaxis in wound healing. Plays a role in platelet activation, secretion of agonists from platelet granules, and in thrombin-induced platelet aggregation. Binding of its cognate ligands - homodimeric pdgfa, homodimeric pdgfb, heterodimers formed by pdgfa and pdgfb or homodimeric pdgfc -leads to the activation of several signaling cascades; the response depends on the nature of the bound ligand and is modulated by the formation of heterodimers between pdgfra and pdgfrb. Phosphorylates pik3r1, plcg1, and ptpn11. Activation of plcg1 leads to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate, mobilization of cytosolic Ca(2+) and the activation of protein kinase C. Phosphorylates pik3r1, the regulatory subunit of phosphatidylinositol 3-kinase, and thereby mediates activation of the AKT1 signaling pathway. Mediates activation of hras and of the MAP kinases mapk1/erk2 and/or mapk3/erk1. Promotes activation of STAT family members stat1, stat3 and stat5a and/or stat5b. Receptor signaling is down-regulated by protein phosphatases that dephosphorylate the receptor and its down-stream effectors, and by rapid internalization of the activated receptor (By similarity). ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Present in an inactive conformation in the absence of bound ligand. Binding of pdgfa and/or pdgfb leads to dimerization and activation by autophosphorylation on tyrosine residues (By similarity). Interacts with homodimeric pdgfa, pdgfb and pdgfc, and with heterodimers formed by pdgfa and pdgfb. monomer in the absence of bound ligand. Interaction with dimeric pdgfa, pdgfb and/or pdgfc leads to receptor dimerization, where both pdgfra homodimers and heterodimers with pdgfrb are observed (By similarity). The activated receptor is rapidly internalized and degraded. Ubiquitinated, leading to its degradation. Autophosphorylated on tyrosine residues upon ligand binding. Autophosphorylation occurs in trans, i.e. one subunit of the dimeric receptor phosphorylates tyrosine residues on the other subunit (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. CSF-1/PDGF receptor subfamily.