The WalE1 effector alters endocytosis.

The most common intracellular bacterial infection is a microbe that manipulates host reproduction and is used in control of insect vectors. Phenotypes induced by have been studied for decades and range from sperm-egg incompatibility to male killing. How alters host biology is less well understood. Previously, we characterized the first effector - WalE1, which encodes a synuclein domain at the N terminus. Purified WalE1 sediments with and bundles actin and when heterologously expressed in flies, increases titer in the developing oocyte. In this work, we first identify the native expression WalE1 by infecting both fly cells and whole animals. WalE1 appears as aggregates, separate from cells. We next show that WalE1 co-immunoprecipitates with the host protein Past1 and that WalE1 manipulates host endocytosis. Yeast expressing WalE1 show deficiency in uptake of FM4-64 dye, and flies harboring mutations in or overexpressing WalE1 are sensitive to AgNO, a hallmark of endocytosis defects. Finally, we also show that null flies harbor more overall and in late egg chambers. Our results identify interactions between a secreted effector and a host protein and point to yet another important host cell process impinged upon by