FIP2, NEW LINKER BETWEEN RAB11 AND RAB14 AT THE CHLAMYDIAL INCLUSION MEMBRANE

LEIVA N; CAPMANY A; GAMBARTE J; DAMIANI MT

Potrero de los Funes, San Luis

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2011

SAIB

Chlamydia trachomatis is an obligate intracellular Gram-negativebacterium that modulates relevant eukaryotic trafficking pathwaysas an adaptive strategy. Chlamydial proteins might be involved inthe recruitment of host Rab GTPases to the inclusion. Rabs are themolecules in charge of intracellular traffic control. We showed thatRab11 and Rab14 are required for bacterial nutrition andreplication. A recently described eukaryotic protein, FIP2possesses a Rab Binding Domain (RBD) that interacts with bothRabs. We examined by confocal microscopy the intracellularlocalization and role of these proteins in Chlamydia-infected cells.FIP2 was recruited to chlamydial inclusions, and colocalized withRab11 and Rab14 at the inclusion membrane differentiallydepending on chlamydial developmental cycle stage. FIP2association to the inclusions was through its RBD domain.Silencing of FIP2 by siRNA reduced Chlamydia trachomatismultiplication, assessed by the counting of inclusion forming units(UFI). Our results demonstrated the requirement of FIP2 for thedevelopment and replication of these bacteria. FIP2 might beinvolved in the formation of macromolecular platforms at thechlamydial inclusion. These data could contribute to theunderstanding of the complex molecular machinery used by thepathogen to manipulate host trafficking pathways for their ownbenefit.