A glioma-derived PDGF A chain homodimer has different functional activities from a PDGF AB heterodimer purified from human platelets.
Glioma-derived growth factor I (GDGF-I) is structurally similar to a platelet-derived growth factor (PDGF) A chain homodimer, whereas PDGF purified from human platelets is a heterodimer of one A and one B chain. Binding experiments revealed that GDGF-I and PDGF bound to a common receptor on human fibroblasts, but also suggested the presence of a second receptor type recognizing only PDGF. In contrast to PDGF, GDGF-I had only a limited mitogenic activity, a low ability to stimulate receptor autophosphorylation and actin reorganization, and no chemotactic activity. GDGF-I did, however, cause transmodulation of EGF receptors, suggesting that it, like PDGF, activates protein kinase C in fibroblasts. These data indicate that different PDGF-like growth factors have different functional activities, which are possibly mediated via different receptors.
Nistér
M
M
Department of Pathology, University Hospital, Uppsala, Sweden.
Hammacher
A
A
Mellström
K
K
Siegbahn
A
A
Rönnstrand
L
L
Westermark
B
B
Heldin
C H
CH
D001667:Binding, Competitive; D001792:Blood Platelets / Q000502:physiology*; D002460:Cell Line; D002633:Chemotaxis; D004261:DNA Replication; D066246:ErbB Receptors / Q000378:metabolism; D005910:Glioma / Q000503:physiopathology*; D006801:Humans; D046911:Macromolecular Substances; D008297:Male; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000302:isolation & purification / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D012867:Skin / Q000378:metabolism
D046911:Macromolecular Substances; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D066246:ErbB Receptors; D017479:Receptors, Platelet-Derived Growth Factor