Guillermo Velasco

The small GTPase Rac1 (Ras‐related C3 botulinum toxin substrate 1) has been implicated in cancer progression and in the poor prognosis of various types of tumors. Rac1 SUMOylation occurs during epithelial‐mesenchymal transition (EMT), and it is required for tumor cell migration and invasion. Here we identify POTEE (POTE Ankyrin domain family member E) as a novel Rac1‐SUMO1 effector involved in breast cancer malignancy that controls invadopodium formation through the activation of Rac1‐SUMO1. POTEE activates Rac1 in the invadopodium by recruiting TRIO‐GEF (triple functional domain protein), and it induces tumor cell proliferation and metastasis in vitro and in vivo . We found that the co‐localization of POTEE with Rac1 is correlated with more aggressive breast cancer subtypes. Given its role in tumor dissemination, the leading cause of cancer‐related deaths, POTEE could represent a potential therapeutic target for these types of cancer.