Presenilins 1 and 2 are two homologous proteins which, when mutated, appear responsible for most of the early-onset familial forms of Alzheimer's disease. Among various functional aspects, presenilins appear to behave as chaperoning partners of a series of proteins including the P-amyloid precursor protein. Recently, presenilins were shown to interact with Rab11, a GTPase involved in intracellular transport. This suggested that Rab11-presenilin interaction could influence the routing of beta APP and thereby modulate its maturation. In this context, we examined whether overexpression of Rab11 or its constitutively active mutant Rab11Q70L could affect beta APP maturation in human HEK293 cells. We show here that the overexpression of both Rab11-related proteins does not modify the recovery of secreted sAPP alpha or A beta in HEK293 cells expressing wild-type beta APP or beta APP harboring the Swedish double mutation. These data indicate that Rab11 does not influence beta APP processing in HEK293 cells. However, it does not preclude the possibility for Rab11 to modulate other presenilin-mediated functions in human cells.