描述:
PDGF was originally discovered as a major mitogenic factor in serum but not in plasma.
PDGF is stored in platelet α granules and released upon platelet activation. Besides
megakaryocytes, other cell types, including endothelial cells, monocyte/macrophages,
vascular smooth muscle cells, fibroblasts, cytotrophoblasts and a variety of transformed
or neoplastic cells, have been shown to produce PDGF. PDGFs are disulfidelinked dimers.
The subunits of the PDGF dimers are homologous polypeptides designated PDGF-A and
PDGF-B chains. Natural PDGFs can exist either as homodimers (PDGF-AA, PDGF-BB) or
heterodimers (PDGF-AB). Although all three isoforms of PDGF exist in human platelets,
R&D Systems hPDGF consists predominantly of hPDGF-AB heterodimers.Two distinct PDGF
receptors, the α-receptor and the β-receptor, have been identified. The two receptors are
structurally related, with an extracellular portion containing five immunoglobulinlike domains,
a single transmembrane region, and an intracellular portion with a proteintyrosine kinase
domain. The αreceptor binds both the A and B chains with high affinity whereas the βreceptor
binds only the Bchain with high affinity. Receptor dimerization is induced upon ligand binding.
In addition to being a potent mitogen for cells of mesenchymal origin, PDGF has also been
shown to be a potent chemoattractant for mesenchymal cells, mononuclear cells and neutrophils
and has been reported to be important in the modification of cellular matrix constituents.
原厂资料:
PDGF was originally discovered as a major mitogenic factor in serum but not in plasma.
PDGF is stored in platelet α granules and released upon platelet activation. Besides
megakaryocytes, other cell types, including endothelial cells, monocyte/macrophages,
vascular smooth muscle cells, fibroblasts, cytotrophoblasts and a variety of transformed
or neoplastic cells, have been shown to produce PDGF. PDGFs are disulfidelinked dimers.
The subunits of the PDGF dimers are homologous polypeptides designated PDGF-A and
PDGF-B chains. Natural PDGFs can exist either as homodimers (PDGF-AA, PDGF-BB) or
heterodimers (PDGF-AB). Although all three isoforms of PDGF exist in human platelets,
R&D Systems hPDGF consists predominantly of hPDGF-AB heterodimers.Two distinct PDGF
receptors, the α-receptor and the β-receptor, have been identified. The two receptors are
structurally related, with an extracellular portion containing five immunoglobulinlike domains,
a single transmembrane region, and an intracellular portion with a proteintyrosine kinase
domain. The αreceptor binds both the A and B chains with high affinity whereas the βreceptor
binds only the Bchain with high affinity. Receptor dimerization is induced upon ligand binding.
In addition to being a potent mitogen for cells of mesenchymal origin, PDGF has also been
shown to be a potent chemoattractant for mesenchymal cells, mononuclear cells and neutrophils
and has been reported to be important in the modification of cellular matrix constituents.