Vascular patterning by Eph receptor tyrosine kinases and ephrins

Ephrins are ligands for the Eph receptor tyrosine kinases, which play important roles in patterning nervous and vascular systems. Ephrin-A1 is a glycosylphosphatidylinositol-anchored ligand that binds to the EphA receptor tyrosine kinases. In the present study, we have identified a new ephrin-A1 isoform, denoted ephrin-A1b (ephrin-A1 isoform b). Compared with the originally described ephrin-A1 sequence, ephrin-A1a [Holzman, Marks and Dixit (1990) Mol. Cell. Biol. 10, 5830–5838], ephrin-A1b lacks a segment of 22 amino acids (residues 131–152). At the transcript level, exon 3 is spliced out in the transcript encoding ephrin-A1b. Transfection of HEK-293T cells (human embryonic kidney 293 cells) with an ephrin-A1b-expressing plasmid resulted in a significant expression of the protein on the cell surface. However, soluble EphA2 receptor (EphA2-Fc) bound weakly to ephrin-A1b-expressing transfectants, but bound strongly to ephrin-A1a-expressing transfectants. Ephrins have been shown to undergo regulated cleavage after interaction with their receptors. This process is inhibited by co-expression of ephrin-A1a and ephrin-A1b, indicating that ephrin-A1b influences the cleavage process. Taken together, these findings indicate that this newly described isoform may regulate the function of its ephrin-A1a counterpart.

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mRNA expression of ephrins and Eph receptor tyrosine kinases in the neonatal and adult mouse central nervous system

Journal of Neuroscience Research ◽

10.1002/jnr.10457 ◽

2002 ◽

Vol 71 (1) ◽

pp. 7-22 ◽

Cited By ~ 101

Author(s):

Daniel J. Liebl ◽

Carol J. Morris ◽

Mark Henkemeyer ◽

Luis F. Parada

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Mrna Expression ◽

Tyrosine Kinases ◽

Adult Mouse ◽

Receptor Tyrosine Kinases ◽

Eph Receptor ◽

Mouse Central Nervous System

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Regulation of Tumor Initiation and Metastatic Progression by Eph Receptor Tyrosine Kinases

Advances in Cancer Research - Guidance Molecules in Cancer and Tumor Angiogenesis ◽

10.1016/b978-0-12-386503-8.00001-6 ◽

2012 ◽

pp. 1-20 ◽

Cited By ~ 35

Author(s):

Jin Chen

Keyword(s):

Tyrosine Kinases ◽

Receptor Tyrosine Kinases ◽

Tumor Initiation ◽

Metastatic Progression ◽

Eph Receptor

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Quantifying the strength of heterointeractions among receptor tyrosine kinases from different subfamilies: Implications for cell signaling

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.013639 ◽

2020 ◽

Vol 295 (29) ◽

pp. 9917-9933 ◽

Cited By ~ 1

Author(s):

Michael D. Paul ◽

Hana N. Grubb ◽

Kalina Hristova

Keyword(s):

Growth Factor ◽

Tyrosine Kinases ◽

Receptor Tyrosine Kinases ◽

Growth Factor Receptor ◽

Vascular Endothelial ◽

Eph Receptor ◽

Vital Cell ◽

Cell Processes ◽

Epidermal Growth ◽

Endothelial Growth Factor

Receptor tyrosine kinases (RTKs) are single-pass membrane proteins that control vital cell processes such as cell growth, survival, and differentiation. There is a growing body of evidence that RTKs from different subfamilies can interact and that these diverse interactions can have important biological consequences. However, these heterointeractions are often ignored, and their strengths are unknown. In this work, we studied the heterointeractions of nine RTK pairs, epidermal growth factor receptor (EGFR)–EPH receptor A2 (EPHA2), EGFR–vascular endothelial growth factor receptor 2 (VEGFR2), EPHA2–VEGFR2, EPHA2–fibroblast growth factor receptor 1 (FGFR1), EPHA2–FGFR2, EPHA2–FGFR3, VEGFR2–FGFR1, VEGFR2–FGFR2, and VEGFR2–FGFR3, using a FRET-based method. Surprisingly, we found that RTK heterodimerization and homodimerization strengths can be similar, underscoring the significance of RTK heterointeractions in signaling. We discuss how these heterointeractions can contribute to the complexity of RTK signal transduction, and we highlight the utility of quantitative FRET for probing multiple interactions in the plasma membrane.

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