Rab GTPasas regulate vesicle recycling from phagosomes in streptolysin O permeabilized macrophages.

LEIVA N; PAVAROTTI M; COLOMBO MI; DAMIANI MT

Universidad Nacional de Cuyo. Mendoza. Argentina.

Congreso; XXI Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2003

Sociedad de Biología de Cuyo

Phagocytosis is a process by which macrophages engulf large extracellular particles. During phagosome maturation, many proteins and membrane are recycled back to the cell surface. To study the involvement of monomeric GTPases in vesicle recycling from the phagosomal compartment, we reconstitute this transport event in macrophages permeabilized with streptolysin O (SLO). In permeabilized cells, we can assess the intracellular effect of proteins or reagents that do not cross the plasma membrane. Addition of a non hydrolysable form of GTP stimulates recycling from phagosomes, whereas GDP diminishes this vesicle traffic step. Moreover, the addition of Rab11:WT GTPase to permeabilized cells enhances the recycling from the phagosomal compartment, whereas the addition of Rab11:S25N GTPase, a mutant preferentially locked in the GDP-bound state, decreases this process. These results demonstrate that the monomeric GTPase Rab11 regulate the recycling from the phagosomal compartment and that SLO-permeabilized macrophages are a useful tool to study the molecular machinery involved in trafficking along the phagocytic pathway.