Fig. 5.

A hypothetic model showing the role of AJAP1 in primary endothelial cells. In HUVECs, AJAP1 localizes at the microtubules. It is either a direct binding of AJAP1 or an association via an adaptor protein or protein complex. The interaction with microtubules affects cell migration and invasion, thereby suggesting an attenuating effect on angiogenesis. We hypothesize that these effects are the result of microtubule-bound AJAP1 influencing vesicle transport regulation mechanisms by decreasing trafficking velocity or affecting microtubule dynamic instability by a stabilizing effect. In invasive tumors, it was shown that AJAP1 expression is deregulated by hypermethylation of its promoter. We consider this regulation mechanism of AJAP1 expression in endothelial cells.