Phosphorylation regulates human polη stability and damage bypass throughout the cell cycle

DNA translesion synthesis (TLS) is a crucial damage tolerance pathway that oversees the completion of DNA replication in the presence of DNA damage. TLS polymerases are capable of bypassing a distorted template but they are generally considered inaccurate and they need to be tightly regulated. We have previously shown that polη is phosphorylated on Serine 601 after DNA damage and we have demonstrated that this modification is important for efficient damage bypass. Here we report that polη is also phosphorylated by CDK2, in the absence of damage, in a cell cycle-dependent manner and we identify serine 687 as an important residue targeted by the kinase. We discover that phosphorylation on serine 687 regulates the stability of the polymerase during the cell cycle, allowing it to accumulate in late S and G2 when productive TLS is critical for cell survival. Furthermore, we show that alongside the phosphorylation of S601, the phosphorylation of S687 and S510, S512 and/or S514 are important for damage bypass and cell survival after UV irradiation. Taken together our results provide new insights into how cells can, at different times, modulate DNA TLS for improved cell survival

Real-world use of Safinamide in motor fluctuating Parkinson’s disease patients in Italy

Introduction: Safinamide is a recent antiparkinsonian drug that modulates both dopaminergic and glutamatergic systems with positive effects on motor and nonmotor symptoms of Parkinson's disease (PD). Here, we aimed to describe the efficacy and safety of safinamide in the Italian PD patients in real-life conditions. Methods: We performed a sub-analysis of the Italian cohort of the SYNAPSES study, a multi-country, multi-center, retrospective-prospective cohort observational study, designed to investigate the use of safinamide in routine clinical practice. Patients received for the first time a treatment with safinamide and were followed up for 12 months. The analysis was conducted on the overall population and in subgroups of interest: i) patients > 75 years, ii) patients with relevant comorbidities and iii) patients affected by psychiatric symptoms. Results: Italy enrolled 616/1610 patients in 52 centers, accounting for 38% of the entire SYNAPSES cohort. Of the patients enrolled, 86.0% were evaluable at 12 months, with 23.3% being > 75 years, 42.4% with psychiatric conditions and 67.7% with relevant comorbidities. Safinamide was effective on motor symptoms and fluctuations as measured through the Unified PD rating scale III and IV scores, and on the total score, without safety issues in none of the subgroups considered. Conclusion: The SYNAPSES data related to Italian patients confirms the good safety profile of safinamide even in special groups of patients. Motor fluctuations and motor impairment improved at the follow-up suggesting the significant role of safinamide in managing motor symptoms in PD patients

Unstable TTTTA/TTTCA expansions in MARCH6 are associated with Familial Adult Myoclonic Epilepsy type 3

Familial Adult Myoclonic Epilepsy (FAME) is a genetically heterogeneous disorder characterized by cortical tremor and seizures. Intronic TTTTA/TTTCA repeat expansions in SAMD12 (FAME1) are the main cause of FAME in Asia. Using genome sequencing and repeat-primed PCR, we identify another site of this repeat expansion, in MARCH6 (FAME3) in four European families. Analysis of single DNA molecules with nanopore sequencing and molecular combing show that expansions range from 3.3 to 14 kb on average. However, we observe considerable variability in expansion length and structure, supporting the existence of multiple expansion configurations in blood cells and fibroblasts of the same individual. Moreover, the largest expansions are associated with micro-rearrangements occurring near the expansion in 20% of cells. This study provides further evidence that FAME is caused by intronic TTTTA/TTTCA expansions in distinct genes and reveals that expansions exhibit an unexpectedly high somatic instability that can ultimately result in genomic rearrangements