Five PDGF B amino acid substitutions convert PDGF A to a PDGF B-like transforming molecule.
We used site-directed mutagenesis to determine the minimum number of PDGF B residues needed to convert PDGF A to a potently transforming PDGF B-like molecule. Substitution of two PDGF B subdomains, 106-115 and 135-144, were found to be critical. These substitutions were sufficient to broaden the ability of PDGF A to activate beta as well as alpha platelet-derived growth factor (PDGF) receptors and increase its transforming efficiency to that of PDGF B. Within subdomain I, either PDGF B residues Arg-109 and Asn-115 or Arg-109, Leu-110, and Arg-113, in combination with subdomain II PDGF B residues Asn-136, Arg-137, and Arg-142 were identified as being essential. Those mutants with transforming ability comparable with PDGF B showed significantly lower efficiencies of beta receptor triggering. Thus, our studies identify a small number of PDGF B amino acids indispensable for beta PDGF receptor interaction and suggest that a low level of beta PDGF receptor activation is sufficient to dramatically increase PDGF transforming efficiency in NIH 3T3 cells.
LaRochelle
W J
WJ
Laboratory of Cellular and Molecular Biology, National Institutes of Health, Bethesda, Maryland 20892.
Pierce
J H
JH
May-Siroff
M
M
Giese
N
N
Aaronson
S A
SA
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D004261:DNA Replication; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D019000:Phosphotyrosine; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D014162:Transfection; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D046911:Macromolecular Substances; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D017479:Receptors, Platelet-Derived Growth Factor