Myo1C a new regulator of actin in Chlamydia trachomatis infection

CAPMANY A; CUERVO BUSTAMANTE ME; SCHAUER, KRISTINE; DAMIANI MT

Paris

Congreso; Cell la Vie; 2021

Société de Biologie Cellulaire de France (SBCF)

Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium and the most frequent bacterial agent of sexually transmitted infections. This bacterium modifies the actin cytoskeleton to ensure its entry and development. The myosin superfamily plays a key role in modulation of the actin cytoskeleton. However, the involvement of myosins in chlamydial infection has been poorly explored. We studied Myo1C with the aim to characterize the role of this myosin in actin cytoskeleton modulation in C. trachomatis infection. This myosin is a single-headed class I myosin that is enriched in dynamic regions of the plasma membrane, where it modulates actin network. We recently published that Myo1C stabilizes actin at the Golgi apparatus facilitating the arrival of incoming transport carriers at this organelle. Thus, the stabilization of actin filaments at membranes and its linkage seems to be a general function of Myo1C. We observed, by confocal microscopy, that endogenous and over-express Myo1C was recruited to the C. trachomatis inclusion. The knockdown of Myo1C impaired the C. trachomatis development and caused the destabilization of the actin belt that surrounds the inclusion. Moreover, at 72 hours post-infection, Myo1C was recruited at sites showing high concentration of actin fibers where the bacterial exit by extrusion is taking place. Additionally, the chlamydial inclusion was positioned at the top of the cell, and Myo1C was recruited to the inclusion membrane with greater intensity under actin filaments disruption. Based on our results, we propose that MYO1C links the inclusion to the surrounding actin belt, which could help to stabilize the positioning of the inclusion. Moreover, the interaction of Myo1C with the actin belt and its role in stabilizing actin could be key in the extrusion process.