Effector that enhances P.infestans colonization of host plant leaves (PubMed:25936676). During the early stages of P.infestans infection, interacts with and stabilizes host potato K-homology (KH) RNA-binding protein KRBP1, leading to its accumulation (PubMed:25936676). Interacts with host KRBP1. Forms a ring around the nucleolus. Nuclear localization is necessary to promote P.infestans colonization. Expression is induced during host plant infection. The RxLR-dEER motif acts to carry the protein into the host cell cytoplasm through binding to cell surface phosphatidylinositol-3-phosphate. Belongs to the RxLR effector family.