Structural determinants in the platelet-derived growth factor alpha-receptor implicated in modulation of chemotaxis

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

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.

Detaljer

Författare
  • Koutaro Yokote
  • Seijiro Mori
  • Agneta Siegbahn
  • Lars Rönnstrand
  • Christer Wernstedt
  • Carl-Henrik Heldin
  • Lena Claesson-Welsh
Externa organisationer
  • External Organization - Unknown
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Läkemedelskemi

Nyckelord

Originalspråkengelska
Sidor (från-till)5101-5111
TidskriftJournal of Biological Chemistry
Volym271
Utgåva nummer9
StatusPublished - 1996
PublikationskategoriForskning
Peer review utfördJa
Externt publiceradJa