Phosphorylation of nuclear Tau is modulated by distinct cellular pathways

Post-translational protein modification controls the function of Tau as a scaffold protein linking a variety of molecular partners. This is most studied in the context of microtubules, where Tau regulates their stability as well as the distribution of cellular components to defined compartments. However, Tau is also located in the cell nucleus; and is found to protect DNA. Quantitative assessment of Tau modification in the nucleus when compared to the cytosol may elucidate how subcellular distribution and function of Tau is regulated. We undertook an unbiased approach by combing bimolecular fluorescent complementation and mass spectrometry in order to show that Tau phosphorylation at specific residues is increased in the nucleus of proliferating pluripotent neuronal C17.2 and neuroblastoma\ua0SY5Y cells. These findings were validated with the use of nuclear targeted Tau and subcellular fractionation, in particular for the phosphorylation at T181, T212 and S404. We also report that the DNA damaging drug Etoposide increases the translocation of Tau to the nucleus whilst reducing its phosphorylation. We propose that overt phosphorylation of Tau, a hallmark of neurodegenerative disorders defined as tauopathies, may negatively regulate the function of nuclear Tau in protecting against DNA damage

Muscle Activity During Sleep in Human Subjects, Rats, and Mice: Towards Translational Models of REM Sleep Without Atonia

Rapid-eye-movement (REM) sleep without atonia (RSWA) is a marker of REM sleep behavior disorder (RBD) and is common in narcolepsy. Available techniques for electromyogram (EMG) analysis are species-specific, limiting translational research on RSWA. We developed an automated technique based on distributions of normalized EMG values (DNE) to overcome this limitation. With DNE, we tested whether the control of neck and tibialis anterior (TA) muscles during sleep in wild-type rats and mice validly models the control of submentalis (chin) and TA muscles in healthy humans. We then applied DNE to REM sleep recordings of patients with idiopathic RBD and of mouse models of narcolepsy, testing for a common DNE signature of RSWA