ROLE OF ORP1L AND NPC1 PROTEINS IN THE BIOGENESIS OF THE Coxiella burnetii PARASITOPHOROUS VACUOLE

ORTIZ RM; DISTEL JS; ALBANES M; AGUILERA MO; BERÓN W

Mar cel Plata

Congreso; LI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2015

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Rab7, RILP (Rab7-interacting lysosomal protein), ORP1L (OBP-related protein 1L) and Dynein form a motor complex that plays role in endocytic trafficking. ORP1L senses cholesterol in membranes of endo-lysosomes andNPC1 (Niemman-Pick protein C1) is an endo-lysosome protein that transport cholesterol to other membranous compartment. Motor complex transports late endosomes containing high cholesterol concentration towardmicrotubule minus end. C burnetii (Cb) is an intracellular pathogen that transits the phagocytic pathway of host cell to form a parasitophorous vacuole (PV) with endo-lysosome characteristics. To determine the role of ORP1L in the PV biogenesis, HeLa cells were co-transfected with pGFP-ORP1L or its mutant -ORP1LORD and pRFP-p150Glued or -RILP, and then infected. To study the NPC1 in PV formation, HeLa cells were infected followed by treatment with NPC1 inhibitor U188666A. Cells were processed for Indirect Immunofluorescence. Cb intracellular multiplication, number and size of PVs were estimated. The results showed that wild type forms of overexpressed proteins did not affect the determined parameters while the mutants decreased the size and increased the number of PV and diminished Cb replication. The U188666A produced similar effects tothe mutant. Our results suggest an important role of proteins that regulate membrane cholesterol homeostasis in the PV biogenesis.