Distinct patterns of tau-dependent process formation in mammalian cell lines

Tau is a microtubule-associated protein involved in axonal elongation and central to the pathogenesis of a number of neurodegenerative conditions. To better establish the contribution of the cellular context to tau-dependent microtubule organization, we compared the phenotypes resulting from heterologous tau expression in different mammalian cell lines after disruption of the actin cytoskeleton. After cytochalasin D treatment, tau-expressing CHO cells display one or two long neurite-like extensions whereas cells transfected with MAP2c developed multiple shorter processes. By contrast, under the same conditions, tau-transfected PtK2 cells elaborate microtubule bundles forming numerous processes. These results suggest that cell-specific factors are involved in tau-dependent microtubule organization, a notion that could facilitate functional assessment of tau abnormalities associated with neurodegenerative disease.