Phosphorylation of tau protein is not affected in mice lacking apolipoprotein E.

An interaction between the apolipoprotein E (apoE) type 3 and the microtubule-associated protein tau has been demonstrated in vitro and suggested to modulate tau phosphorylation and/or formation of paired helical filaments. To evaluate in vivo the potential interaction between tau and apoE, we have investigated the expression and phosphorylation status of tau in the brain of apoE-deficient mice, using a panel of antibodies reacting with tau in a phosphorylation-dependent manner. The pattern and intensity of immunohistochemical labelling and the pattern of tau immunoreactivity on Western blots were similar in control and apoE-deficient mice. These results suggest that a lack of expression of apoE does not interfere with the expression, distribution and phosphorylation status of tau proteins.