Description of Project:

The ADAMs (for A Disintegrin And Metalloproteinase) are a novel family of cell surface proteins with a unique domain structure. To date more than 30 ADAMs have been identified in organisms ranging from yeast to humans. Functions of ADAM proteins can be separated into two categories, as adhesion molecules and as proteases that can mediate the cleavage of other proteins from the cell surface through a process termed ectodomain shedding. The aim of my thesis project was to characterize potential functions of ADAM family proteins in human endothelial cells. Toward this end we have focused on two ADAM family members, ADAM 15, a novel ADAM cloned in our lab from human endothelial cells which contains a unique RGD integrin-binding motif, and ADAM 17 (TACE), which was cloned as the protease responsible for cleavage and shedding of tumor necrosis factor alpha from the surface of inflammatory cells. From this work we have published three key observations, 1) A novel family of retroviral vectors allows efficient gene expression in primary human endothelial cells, 2) ADAM 15 localizes to sites of cell-cell contact, increases cell-cell binding, and inhibits cell migration and proliferation in NIH3T3 cells, and 3) ADAM 17 (TACE) mediates the cleavage and shedding of the endothelial chemokine fractalkine.

Publications:

1. Garton, K.J., Ferri, N.F., and Raines, E.W. (2002). Efficient expression of exogenous genes in primary vascular cells using IRES-based retroviral vectors. Biotechniques, in press.
2. Garton, K. J., Gough, P. J., Blobel, C. P., Murphy, G., Greaves, D. R., Dempsey, P. J., and Raines, E. W. (2001). Tumor necrosis factor-alpha-converting enzyme (ADAM17) mediates the cleavage and shedding of fractalkine (CX3CL1). J Biol Chem 276, 37993-8001.
3. Herren, B., Garton, K. J., Coats, S., Bowen-Pope, D. F., Ross, R., and Raines, E. W. (2001). ADAM15 overexpression in NIH3T3 cells enhances cell-cell interactions. Exp Cell Res 271, 152-60.
4. Levkau, B., Garton, K. J., Ferri, N., Kloke, K., Nofer, J. R., Baba, H. A., Raines, E. W., and Breithardt, G. (2001). xIAP induces cell-cycle arrest and activates nuclear factor-kappaB : new survival pathways disabled by caspase-mediated cleavage during apoptosis of human endothelial cells. Circ Res 88, 282-90.