Pleckstrin homology domain-containing serine/threonine kinase plays a crucial role in the survival and phagocytosis of Entamoeba histolytica.

Kinases are critical regulators of parasite survival, cytoskeletal dynamics, and endocytic processes. Entamoeba histolytica encodes 372 kinases, many of which remain functionally uncharacterized. This study characterizes EhPHDK, an AGC-family kinase essential for pseudopod formation, phagocytosis, and pinocytosis. Structural modelling suggests an autoregulatory mechanism via its PH domain, potentially modulating kinase activity. Bio-layer interferometry identified a crucial amino acid sequence facilitating interaction with EhCaBP1, implicating EhPHDK in endocytic regulation. Live-cell imaging and immunostaining confirmed its dynamic recruitment to the plasma membrane, colocalizing with EhCaBP1 during phagocytosis initiation and progression. Gene silencing severely impaired parasite viability, reducing growth by 90%, while RBC uptake assays demonstrated its indispensable role in phagocytosis. The regulatory interplay between EhPHDK and cytoskeletal components underscores its function in actin-driven processes. Given its divergence from host kinases, EhPHDK presents a promising therapeutic target for amebiasis. This study provides novel insights into kinase-mediated cytoskeletal remodelling, advancing our understanding of E. histolytica pathogenesis and offering potential avenues for intervention in parasitic survival mechanisms.