Structural determinants in the platelet-derived growth factor alpha-receptor implicated in modulation of chemotaxis
Författare
Summary, in English
Activation of the platelet-derived growth factor (PDGF) beta-receptor leads to cell growth and chemotaxis. The PDGF alpha-receptor also mediates a mitogenic signal, but fails to induce cell migration in certain cell types. To examine this difference in signal transduction, a series of point-mutated PDGF alpha-receptors were analyzed. Porcine aortic endothelial cells expressing mutant PDGF alpha-receptors, in which tyrosine residues 768, 993, or 1018 were changed to phenylalanine residues migrated toward PDGF, whereas wild-type alpha-receptors and mutant alpha-receptors changed at tyrosine residues 720, 944, or 988 failed to migrate. All mutant receptors were mitogenically active and their capacity to activate phosphatidylinositol 3'-kinase and phospholipase C-gamma was not different from that of the wild-type receptor. Tyr-768 was found to be phosphorylated in PDGF-stimulated cells; in the Y768F mutant, there was a considerable increase in phosphorylation of Ser-767. Tyr-993 was not phosphorylated, but mutation of this tyrosine residue to a phenylalanine residue resulted in increased efficiency of phosphorylation on Tyr-988. Tyr-1018 is known to be an autophosphorylation site. Phosphorylated Tyr-768 and Tyr-1018 may bind signal transduction molecules involved in negative modulation of the chemotactic signaling capacity, whereas phosphorylated Tyr-988 may mediate increased chemotaxis. Thus our data indicate that the PDGF alpha-receptor has an intrinsic ability to transduce a chemotactic signal, and that this signal is counteracted by overriding negative signals.
Publiceringsår
1996
Språk
Engelska
Sidor
5101-5111
Publikation/Tidskrift/Serie
Journal of Biological Chemistry
Volym
271
Issue
9
Dokumenttyp
Artikel i tidskrift
Förlag
American Society for Biochemistry and Molecular Biology
Ämne
- Medicinal Chemistry
Nyckelord
- Amino Acid Sequence Animals Aorta Base Sequence Cell Line *Chemotaxis/drug effects Endothelium
- Vascular/*physiology Enzyme Activation Humans Inositol Phosphates/metabolism Isoenzymes/metabolism Kinetics Molecular Sequence Data Mutagenesis
- Site-Directed Oligodeoxyribonucleotides Peptide Fragments/chemistry/isolation & purification Phenylalanine Phosphatidylinositol 3-Kinases Phosphopeptides/chemistry/isolation & purification Phosphotransferases (Alcohol Group Acceptor)/metabolism Platelet-Derived Growth Factor/*pharmacology *Point Mutation Receptor
- Platelet-Derived Growth Factor alpha Receptors
- Platelet-Derived Growth Factor/biosynthesis/*chemistry/*physiology Recombinant Proteins/biosynthesis/chemistry/metabolism Signal Transduction Swine Transfection Type C Phospholipases/metabolism Tyrosine
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1083-351X