The two PDGF receptors maintain conserved signaling in vivo despite divergent embryological functions
R A Klinghoffer1, P F Mueting-Nelsen, A Faerman
1Program in Developmental Biology and Division, Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Abstract:
Gene targeting studies have indicated that the two receptors for PDGF, alpha and beta, direct unique functions during development. Distinct ligand affinities, patterns of gene expression, and/or mechanisms of signal relay may account for functional specificity of the two PDGF receptor isoforms. To distinguish between these factors, we have created two complementary lines of knockin mice in which the intracellular signaling domains of one PDGFR have been removed and replaced by those of the other PDGFR. While both lines demonstrated substantial rescue of normal development, substitution of the PDGFbetaR signaling domains with those of the PDGFalphaR resulted in varying degrees of vascular disease. This observation provides a framework for discussing the evolution of receptor tyrosine kinase functional specificity.
Insights
This study investigated the roles of platelet-derived growth factor receptors (PDGF-R) in development using knockin mice. Replacing PDGF-betaR signaling domains with PDGF-alphaR domains caused vascular disease, highlighting receptor signaling specificity.
Area of Science:
- Molecular Biology
- Developmental Biology
- Genetics
Background:
- Platelet-derived growth factor receptors (PDGF-R), alpha and beta, exhibit distinct developmental functions.
- Functional specificity may arise from differences in ligand affinity, gene expression, or signal transduction pathways.
Purpose of the Study:
- To elucidate the specific contributions of PDGF-R signaling domains to their unique developmental roles.
- To differentiate the roles of ligand binding versus intracellular signaling in PDGF-R functional specificity.
Main Methods:
- Generation of two complementary lines of knockin mice.
- Exchanging the intracellular signaling domains between PDGF-alphaR and PDGF-betaR.
Main Results:
- Both knockin mouse lines showed significant rescue of normal development.
- Mice with PDGF-betaR signaling domains replaced by PDGF-alphaR domains exhibited varying degrees of vascular disease.
Conclusions:
- Intracellular signaling domains play a critical role in determining PDGF-R functional specificity during development.
- These findings offer insights into the evolution of receptor tyrosine kinase specificity and its implications for vascular health.
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