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POSTER NO: 251 Overexpression of Cytoplasmic Tail of ADAM22 in SHG44 Cells Inhibits Cell Adhesion and Spreading - mediated by competing binding to 14-3-3Zeta protein
Pengcheng Zhu, Rener Xu, Yingying Sang, Jing Zhao, Changben Li, Shouyuan Zhao ADAM family consists of a number of transmembrane proteins that contain a disintegrin and metalloprotese domain. Therefore, they all potentially have cell adhesion and protease activities. One of the best-studied ADAM is TNF-alpha converting enzyme or ADAM17, which upon activation releases the biologically active forms of TNF-alpha, an important mediator of inflammation response. However, the function of most ADAM gene products is still unknown. Here, we report that overexpression of the cytoplasmic tail of ADAM22 in human SGH44 cells inhibits cell-matrix adhesion and cell spreading, indicating that ADAM22 play a role in adhesion. By using the cDNA encoding the cytoplasmic tail of ADAM22 as bait in a yeast two-hybrid screen, the 14-3-3zeta isoform was isolated. The interaction between the cytoplasmic tail of ADAM22 and 14-3-3zeta was confirmed by immunoprecipitation and protein pull-down assays. The binding site in the cytoplasmic tail of ADAM22 was mapped to the C-terminal 28 amino acid residue and deletion of the binding site abolished the ability of the over expressed cytoplasmic tail to alter cell adhesion and spreading. In summary, it is the first time that ADAM22 is demonstrated to play a role in adhesion and that its interaction with 14-3-3zeta is essential for its function. |