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Elke Nelson

Mentor: Kris DeMali, Ph.D.
Lab Room: 4-411 BSB
Lab Phone: 319-335-7662

Determining the potential of a Vinculin-Activating Peptide (VAP) as a stimulator of cell adhesion

Strong cell adhesion is critical for regulating cellular growth, and deregulation of this process results in cellular transformation. Vinculin is a cytoskeletal protein that links the actin cytoskeleton to integrins, the major cell surface transmembrane adhesion receptors. My research is focused on understanding whether activators of vinculin can potentiate adhesion and effectively rescue the loss of adhesion that accompanies tumor cell invasion. My hypothesis is that vinculin activators can stimulate cell-matrix adhesion and decrease tumor cell invasion through modulation of integrin receptors.

My results to date show that vinculin-targeting peptide (VTP) increases cell adhesion two-fold in a vinculin- and integrin-dependent manner. What is not known is the vinculin residues required to achieve this effect. I am currently performing experiments to investigate the vinculin residues required for VTP-mediated increased adhesion to the extracellular matrix (ECM). I have designed GFP-tagged vinculin constructs that block VTP binding to vinculin. I generated vinculin null mouse embryo fibroblast (MEF) cell lines stably expressing each of the vinculin mutants and verified their expression by Western blot analysis. Currently, I am characterizing these cell lines expressing the vinculin mutants via immunofluorescence and immunoprecipitation.

An additional aspect of this project is to map the VTP residues sufficient for binding vinculin and increasing cell-matrix adhesion. Using several GFP-tagged VTP truncation mutants, I have determined which residues are required for binding vinculin and co-localizing with vinculin at cell-matrix adhesions. I have found the minimal residues in VTP that are sufficient to co-immunoprecipitate and co-localize with vinculin, and to increase cell-matrix adhesion.

In summary, I have established that VTP increases cell adhesion approximately two-fold. This effect is integrin- and vinculin-dependent. I have begun to map the residues on vinculin required for this effect, as well as the vinculin binding sites within VTP that are sufficient for vinculin binding and increased adhesion. My current focus is investigating the mechanism for VTP-mediated increased adhesion.

Nelson ES, Folkmann AW, Henry MD, DeMali KA. Vinculin activators target integrins from within the cell to increase melanoma sensitivity to chemotherapy. Mol Cancer Res. 2011 Jun;9(6):712-23. Epub 2011 Apr 1. PubMed PMID: 21460181; PubMed Central PMCID: PMC3134390.

Peng X, Nelson ES, Maiers JL, DeMali KA. New insights into vinculin function and regulation. Int Rev Cell Mol Biol. 2011;287:191-231. Review. PubMed PMID:21414589.

Honors and Awards

  • MCB NIH Training Grant Fellowship 2007 & 2008 2008 Travel Award, Molecular & Cellular Biology Re
  • 2004-present Beta Beta Beta National Biological Honors Society, Member; 2008- present American Soc