BPAG1a directly interacts with several vesicle-associated proteins such as dynactin components, transmembrane protein 108, and clathrin. In neuronal cells, BPAG1a was found to co-localize with vesicles along MTs. We thus analysed FITC-dextran uptake by control and BPAG1-knock down C2.7 cells using immunofluorescence microscopy. Three independent experiments consistently showed an average reduction of 20% of the dextran signal intensity in BPAG1-knockdown cells. This observation argues for some perturbation in the endocytic pathway responsible for either a lower dextran uptake and/or an increased recycling of the dextran-containing vesicles back to the plasma membrane. To dissect potential mechanisms responsible for these latter results, we analysed the relation of BPAG1a/b with both early and late endosomal markers by expressing GFP-tagged Rab5 and Rab7, respectively. Immunofluorescence microscopy analysis in C2.7 myoblasts revealed no obvious co-localization between BPAG1a/b and either Rab5 or Rab7. Furthermore, BPAG1 knockdown did not alter the staining pattern of Rab5 and Rab7, an observation implying that BPAG1a/b are associated with a different and less abundant type of vesicles. The latter may explain why BPAG1 knockdown resulted in only a moderate decrease of the dextran signal in C2.7 cells. In a recent study, BPAG1 has been shown to interact and to Ketanserin colocalize with herpes simplex virus capsids in HFFF2 fibroblasts. Furthermore, inactivation of BPAG1 in these cells negatively affected the movement of HSV capsids in anterograde and retrograde manner. In combination with our data, these results suggest that BPAG1 is involved in cargo transport along the MTs rather than in maintenance of MT Almorexant structure and organization in these cells. Nucleophosmin /B23 is an abundant, nucleolar autoantigen and tumor antigen that is over-expressed in rapidly proliferating cells. The wild-type protein is required for normal proliferation and differentiation, and has multiple attributed functions, including transcriptional stimulation, nucleic acid binding and chaperone roles, and interactions with p53/ p14ARF pathways.