Fig. 8.

Lack of tau degradation by the proteasome in neurons. (A) Primary rat cortical neurons were transfected with each tau construct. After 48 hours, neurons were treated with 100 μM cycloheximide and harvested at 0, 12, and 24 hours. Neuronal lysates were analyzed on Western blots probed with antibodies to tau (DAKO) and β-actin. (B) The amount of EGFPtau remaining after cycloheximide treatment for 12 and 24 hours was calculated as the percentage of tau present at 0 hours. Values shown are mean ± standard error of the mean; n = 6. Abbreviations: DIV, days in vitro; EGFP, enhanced green fluorescent protein; Endog, endogenous.