Abstract
Misregulation of the signaling axis formed by the receptor tyrosine kinase (RTK) EphA2 and its ligand, ephrinA1, causes aberrant cell-cell contacts that contribute to metastasis. Solid tumors are characterized by an acidic extracellular medium. We intend to take advantage of this tumor feature to design new molecules that specifically target tumors. We created a novel pH-dependent transmembrane peptide, TYPE7, by altering the sequence of the transmembrane domain of EphA2. TYPE7 is highly soluble and interacts with the surface of lipid membranes at neutral pH, while acidity triggers transmembrane insertion. TYPE7 binds to endogenous EphA2 and reduces Akt phosphorylation and cell migration as effectively as ephrinA1. Interestingly, we found large differences in juxtamembrane tyrosine phosphorylation and the extent of EphA2 clustering when comparing TYPE7 with activation by ephrinA1. This work shows that it is possible to design new pH-triggered membrane peptides to activate RTK and gain insights on its activation mechanism.
| Original language | English |
|---|---|
| Article number | e36645 |
| Journal | eLife |
| Volume | 7 |
| DOIs | |
| State | Published - Sep 2018 |
Funding
This work was supported by NIH grants R01GM120642 (FNB) and R01NS096956 and R01CA155676 (B-CW). We are thankful to Dr. Joshua Bembenek (University of Tennessee), Dr. Daniel DiMaio (Yale) and Dr. Jeff Becker (University of Tennessee) for insightful comments on the manuscript. We thank Roger Koeppe II (University of Arkansas) for providing the GWALP23 peptide, and Dr. Jin Chen (Vanderbilt University) for providing reagents. We are also thankful to Nicholas Wads-worth and Alayna Cameron for helping with experimentation. The SIM and confocal experiments were conducted at the Center for Nanophase Materials Sciences (Oak Ridge National Laboratory), which is a DOE Office of Science User Facility. This work was supported by NIH grants R01GM120642 (FNB) and R01NS096956 and R01CA155676 (B-CW). We are thankful to Dr. Joshua Bembenek (University of Tennessee), Dr. Daniel DiMaio (Yale) and Dr. Jeff Becker (University of Tennessee) for insightful comments on the manuscript. We thank Roger Koeppe II (University of Arkansas) for providing the GWALP23 peptide, and Dr. Jin Chen (Vanderbilt University) for providing reagents. We are also thankful to Nicholas Wadsworth and Alayna Cameron for helping with experimentation. The SIM and confocal experiments were conducted at the Center for Nanophase Materials Sciences (Oak Ridge National Laboratory), which is a DOE Office of Science User Facility.Funder Grant reference number Author National Institute of General Medical Sciences R01GM120642 Francisco N Barrera National Institute of Neurological Disorders and Stroke R01NS096956 Bing-Cheng Wang National Cancer Institute R01CA155676 Bing-Cheng Wang The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
