Screening of DUB activity and specificity by MALDI-TOF mass spectrometry

Deubiquitylases (DUBs) are key regulators of the ubiquitin system which cleave ubiquitin moieties from proteins and polyubiquitin chains. Several DUBs have been implicated in various diseases and are attractive drug targets. We have developed a sensitive and fast assay to quantify in vitro DUB enzyme activity using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Unlike other current assays, this method uses unmodified substrates, such as diubiquitin topoisomers. By analyzing 42 human DUBs against all diubiquitin topoisomers we provide an extensive characterization of DUB activity and specificity. Our results confirm the high specificity of many members of the OTU and JAMM DUB families and highlight that all USPs tested display low linkage selectivity. We also demonstrate that this assay can be deployed to assess the potency and specificity of DUB inhibitors by profiling 11 compounds against a panel of 32 DUBs

Excess α-synuclein worsens disease in mice lacking ubiquitin carboxy-terminal hydrolase L1

Mutations in α-synuclein (αSN) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) have been linked to familial Parkinson's disease (PD). Physical and functional interactions between these two proteins have been described. Whether they act additively in vivo to influence disease has remained controversial. αSN is a presynaptic protein and the major constituent of Lewy inclusions, histopathological hallmarks of PD. UCH-L1 regulates ubiquitin stability in the nervous system and its loss results in neurodegeneration in peripheral and central neurons. Here, we used genetics to show that UCH-L1-deficiency together with excess αSN worsen disease. Double mutant mice show earlier-onset motor deficits, a shorter lifespan and forebrain astrogliosis but the additive disease-worsening effects of UCH-L1-deficiency and excess αSN are not accompanied by microgliosis, ubiquitin pathology or changes in pathological αSN protein levels and species

Fremanezumab for Chronic Migraine Prevention in Japanese Patients: Subgroup Analysis from Two International Trials

Kazumasa Saigoh,1 Takao Takeshima,2 Masami Nakai,3 Yoshiyuki Shibasaki,4 Miki Ishida,5 Xiaoping Ning,6 Steve Barash,6 Yuki Isogai,4 Nobuyuki Koga7 1Department of Neurology, Kindai University School of Medicine, Osaka, Japan; 2Headache Center, Department of Neurology, Tominaga Hospital, Osaka, Japan; 3Medical Affairs, Otsuka Pharmaceutical Co., Ltd., Osaka, Japan; 4Medical Affairs, Otsuka Pharmaceutical Co., Ltd., Tokyo, Japan; 5Headquarters of Clinical Development, Otsuka Pharmaceutical Co., Ltd., Osaka, Japan; 6Teva Branded Pharmaceutical Products R&D, Inc., West Chester, PA, USA; 7Medical Affairs, Otsuka Pharmaceutical Co., Ltd., Tokushima, JapanCorrespondence: Masami Nakai, Medical Affairs, Otsuka Pharmaceutical Co., Ltd., 3-2-27 Otedori, Chuo-ku, Osaka, 540-0021, Japan, Tel +81-80-9026-3806, Email [email protected]: Fremanezumab monoclonal antibody therapy has demonstrated efficacy for chronic migraine (CM) with rapid onset and good tolerability. This subgroup analysis of two clinical trials (Japanese and Korean CM Phase 2b/3 [NCT03303079] and HALO CM Phase 3 [NCT02621931]) aimed to evaluate the efficacy and safety of fremanezumab in Japanese patients.Patients and Methods: Both trials randomly assigned eligible patients at baseline (1:1:1 ratio) to subcutaneous monthly fremanezumab, quarterly fremanezumab, or placebo at 4-week intervals. The primary endpoint was the mean change from baseline in the monthly (28-day) average number of headache days of at least moderate severity during the 12-week period after the first dose of study medication (analyzed by ANCOVA over 12 weeks and MMRM over initial 4 weeks). Secondary endpoints examined other aspects of efficacy, including medication use and disability.Results: A total of 479 and 109 patients were Japanese in the Japanese and Korean CM Phase 2b/3 and HALO CM trials, respectively. Baseline and treatment characteristics were generally similar between treatment groups for both trials. Results of subgroup analyses for the primary endpoint according to ANCOVA demonstrated the superiority of fremanezumab over placebo in Japanese patients (quarterly fremanezumab, p=0.0005; monthly fremanezumab, p=0.0002 in both trials). Results using the MMRM analysis confirmed the rapid onset of action in this population. Results of the secondary endpoints further supported the efficacy of fremanezumab in Japanese patients. Fremanezumab was well tolerated with nasopharyngitis and injection-site reactions representing the most common adverse events in all treatment groups.Conclusion: Despite the limitations of subgroup analyses, these consistent results confirm the efficacy and tolerability of fremanezumab in Japanese patients with CM.Keywords: calcitonin gene-related peptide, chronic migraine, fremanezumab, Japanes

Positive and negative regulation of APP amyloidogenesis by sumoylation

Amyloid β peptide (Aβ) generated from amyloid precursor protein (APP) is central to Alzheimer's disease (AD). Signaling pathways affecting APP amyloidogenesis play critical roles in AD pathogenesis and can be exploited for therapeutic intervention. Here, we show that sumoylation, covalent modification of cellular proteins by small ubiquitin-like modifier (SUMO) proteins, regulates Aβ generation. Increased protein sumoylation resulting from overexpression of SUMO-3 dramatically reduces Aβ production. Conversely, reducing endogenous protein sumoylation with dominant-negative SUMO-3 mutants significantly increases Aβ production. We also show that mutant SUMO-3, K11R, which can only be monomerically conjugated to target proteins, has an opposite effect on Aβ generation to that by SUMO-3, which can form polymeric chains on target proteins. In addition, SUMO-3 immunoreactivity is predominantly detected in neurons in brains from AD, Down's syndrome, and nondemented humans. Therefore, polysumoylation reduces whereas monosumoylation or undersumoylation enhances Aβ generation. These findings provide a regulatory mechanism in APP amyloidogenesis and suggest that components in the sumoylation pathway may be critical in AD onset or progression

Structural basis for conformational plasticity of the Parkinson's disease-associated ubiquitin hydrolase UCH-L1

The ubiquitin C-terminal hydrolase UCH-L1 (PGP9.5) comprises >1% of total brain protein but is almost absent from other tissues [Wilkinson, K. D., et al. (1989) Science 246, 670–673]. Mutations in the UCH-L1 gene have been reported to be linked to susceptibility to and protection from Parkinson's disease [Leroy, E., et al. (1998) Nature 395, 451–452; Maraganore, D. M., et al. (1999) Neurology 53, 1858–1860]. Abnormal overexpression of UCH-L1 has been shown to correlate with several forms of cancer [Hibi, K., et al. (1998) Cancer Res. 58, 5690–5694]. Because the amino acid sequence of UCH-L1 is similar to that of other ubiquitin C-terminal hydrolases, including the ubiquitously expressed UCH-L3, which appear to be unconnected to neurodegenerative disease, the structure of UCH-L1 and the effects of disease associated mutations on the structure and function are of considerable importance. We have determined the three-dimensional structure of human UCH-L1 at 2.4-Å resolution by x-ray crystallography. The overall fold resembles that of other ubiquitin hydrolases, including UCH-L3, but there are a number of significant differences. In particular, the geometry of the catalytic residues in the active site of UCH-L1 is distorted in such a way that the hydrolytic activity would appear to be impossible without substrate induced conformational rearrangements