Figure 9.

Hypothetical mechanism of pRb regulation in tauopathies. The activation of Cdks induces the hyperphosphorylation of pRb and subsequent degradation, which leads the progression of cell cycle to S-phase. The re-activation of cell cycle in post-mitotic neurons might induce hyperphosphorylation of tau and neuronal cell loss. In addition, Cdks, particularly Cdk5, might phosphorylate tau independent of cell cycle regulatory effects (broken line). Cdk5 can directly phosphorylate tau.