The deubiquitinase USP6 affects memory and synaptic plasticity through modulating NMDA receptor stability

人类与其他动物相比的重要区别在于人类拥有高等认知能力，这种能力集中体现在学习记忆和语言表达方面。厦门大学医学院神经科学研究所王鑫教授团队发现人科动物特异性基因USP6作为一个新的NMDA受体调控因子，可通过去泛素化途径调节NMDA型谷氨酸受体的降解和稳定性，进而调控突触可塑性和学习记忆能力。 本研究工作由王鑫教授指导完成，博士生曾凡伟、马学海与硕士生朱琳为共同第一作者，王鑫教授为通讯作者。Ubiquitin-specific protease (USP) 6 is a hominoid deubiquitinating enzyme previously implicated in intellectual disability and autism spectrum disorder. Although these findings link USP6 to higher brain function, potential roles for USP6 in cognition have not been investigated. Here, we report that USP6 is highly expressed in induced human neurons and that neuron-specific expression of USP6 enhances learning and memory in a transgenic mouse model. Similarly, USP6 expression regulates N-methyl-D-aspartate-type glutamate receptor (NMDAR)-dependent long-term potentiation and long-term depression in USP6 transgenic mouse hippocampi. Proteomic characterization of transgenic USP6 mouse cortex reveals attenuated NMDAR ubiquitination, with concomitant elevation in NMDAR expression, stability, and cell surface distribution with USP6 overexpression. USP6 positively modulates GluN1 expression in transfected cells, and USP6 down-regulation impedes focal GluN1 distribution at postsynaptic densities and impairs synaptic function in neurons derived from human embryonic stem cells. Together, these results indicate that USP6 enhances NMDAR stability to promote synaptic function and cognition.This work was partially supported by the National Natural Science Foundation of China (31871077, 81822014, 81571176 to XW; 81701349 to Hongfeng Z.; 81701130 to QZ; and 81471160 to HS), the National Key R&D Program of China (2016YFC1305900 to XW and HS), the Natural Science Foundation of Fujian Province of China (2017J06021 to XW), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to XW and 20720180040 to ZS), Open Research Fund of State Key Laboratory of Cellular Stress Biology, Xiamen University (SKLCSB2019KF012 to QZ), and China Postdoctoral Science Foundation (2017M612130 to QZ).该研究得到了国家自然科学基金面上项目和优秀青年基金项目的支持

Rapid Identification of Bio-Molecules Applied for Detection of Biosecurity Agents Using Rolling Circle Amplification

Detection and identification of pathogens in environmental samples for biosecurity applications are challenging due to the strict requirements on specificity, sensitivity and time. We have developed a concept for quick, specific and sensitive pathogen identification in environmental samples. Target identification is realized by padlock- and proximity probing, and reacted probes are amplified by RCA (rolling-circle amplification). The individual RCA products are labeled by fluorescence and enumerated by an instrument, developed for sensitive and rapid digital analysis. The concept is demonstrated by identification of simili biowarfare agents for bacteria (Escherichia coli and Pantoea agglomerans) and spores (Bacillus atrophaeus) released in field

Improving Precision of Proximity Ligation Assay by Amplified Single Molecule Detection

Proximity ligation assay (PLA) has been proven to be a robust protein detection method. The technique is characterized by high sensitivity and specificity, but the assay precision is probably limited by the PCR readout. To investigate this potential limitation and to improve precision, we developed a digital proximity ligation assay for protein measurement in fluids based on amplified single molecule detection. The assay showed significant improvements in precision, and thereby also detection sensitivity, over the conventional real-time PCR readout

Financial information security approaches and solutions

Attīstoties tehnoloģijām, jo vairāk kļūst nepieciešama finanšu informācijas aizsardzība, jo visi tirgus dalībnieki tiek apdraudēti ar dažāda veida krāpniecisko uzbrukumu riska pastāvēšanu, kuru mērķis ir konfidenciālās informācijas iegūšana un izmantošana, krāpnieku bagātināšanas nolūkā. Darbā tiek izskatīta katra ekonomiskā tirgus dalībnieka drošība - finanšu uzņēmumu, e-komersantu un patērētāju, jo ikkatrs no viņiem ir pakļauts dažādu krāpniecisko uzbrukumu potenciālajam riskam, kas var nozīmēt zaudējumus un kaitējumus reputācijai. Tiek parādīti vispārējie riski un finanšu uzņēmumu drošības politika, kā arī tiek analizēts populārākais krāpšanas veids un e-komersanta krāpniecisku finanšu darījumu pārbaudes sistēma. Tika izpētītas krāpnieciskās lietotāju finanšu datu novākšanas metodes, kā arī ir izskatīti visefektīvākie līdzekļi, lai aizsargātu konfidenciālos datus no šādiem uzbrukumiem.Along with technological progress the need for financial security grows daily, as all representatives of the market are under constant threat of fraudsters trying to gain access to confidential data. The paper includes analysis of all key market players - the financial institution, the merchant and the client, as each one can become a victim of fraud, resulting in financial losses and loss of good reputation. Common risks and security policies of financial institutions are given, popular methods of fraud are analysed along with the system to determine fraudulent financial activity from the merchant's perspective. Methods of retrieving clients' sensitive information by fraudsters are looked into along with the most popular prevention methods

Genome-Wide Detection of Spontaneous Chromosomal Rearrangements in Bacteria

Genome rearrangements have important effects on bacterial phenotypes and influence the evolution of bacterial genomes. Conventional strategies for characterizing rearrangements in bacterial genomes rely on comparisons of sequenced genomes from related species. However, the spectra of spontaneous rearrangements in supposedly homogenous and clonal bacterial populations are still poorly characterized. Here we used 454 pyrosequencing technology and a 'split mapping' computational method to identify unique junction sequences caused by spontaneous genome rearrangements in chemostat cultures of Salmonella enterica Var. Typhimurium LT2. We confirmed 22 unique junction sequences with a junction microhomology more than 10 bp and this led to an estimation of 51 true junction sequences, of which 28, 12 and 11 were likely to be formed by deletion, duplication and inversion events, respectively. All experimentally confirmed rearrangements had short inverted (inversions) or direct (deletions and duplications) homologous repeat sequences at the endpoints. This study demonstrates the feasibility of genome wide characterization of spontaneous genome rearrangements in bacteria and the very high steady-state frequency (20-40%) of rearrangements in bacterial populations

Tandem conjugation of enzyme and antibody on silica nanoparticle for enzyme immunoassay

We present a new type of enzyme-antibody conjugate that simplifies the labeling procedure and increases the sensitivity of enzyme-linked immunosorbent assay (ELISA). The conjugates were prepared through layer-by-layer immobilization of enzyme and antibody on a silica nanoparticle scaffold. A maximal amount of enzyme was immobilized on the nanoparticle, followed by antibody linkage through Dextran 500. The conjugate could be easily purified from unreacted reagents by simple centrifugations. In comparison with the conventional antibody-enzyme conjugate used in ELISA, which often has one or two enzyme molecules per antibody, the new type of conjugate contained more enzyme molecules per antibody and provided a much higher signal and increased sensitivity. When used in an ELISA detection of the hepatitis B surface antigen (HBsAg), the detection limit was three times lower than that of the commercially available ELISA kit. (C) 2010 Elsevier Inc. All rights reserved.National Natural Science Foundation of China [30500454]; Natural Science Foundation of Fujian Province of China [2007J0112

Detection of VEGF by PLA digital ASMD readout.

<p>Blue dots: detected signal; Diamond symbol: CV%.</p

Junction microhomology analysis.

<p>The distribution of overlapping microhomologies at junctions was compared between the three datasets (gen48, gen144 and gen240) and one simulated dataset using 20 million in silico chimeric reads. The observed junction microhomology distribution in the datasets gen48, gen144 and gen 240 were represented by triangles and the simulated distributions were represented by boxplot. (A) Comparison between the dataset gen48 and the simulated dataset (181 rearrangements). (B) Comparison between the dataset gen144 and the simulated dataset (120 rearrangements). (C) Comparison between the dataset gen240 and the simulated dataset (42 rearrangements).</p

Workflow of detection and verification of SGRs in <i>S. typhimurium</i>.

<p>The SGRs detection and verification procedures in this work are as followings: (i) bacterial cells were grown in a chemostat for five days; (ii) samples were collected at each day and 454 pyrosequencing was performed on genomic DNA prepared from three samples collected at day one, two and three; (iii) reads with ‘split mapping’ signature were mined from the three datasets and further subjected to the confirmatory screening based on the three listed criteria; (iv) A substantial fraction of putative rearrangements were selected for experimental verification using padlock probe hybridization and/or PCR.</p

Schematic illustration of protein detection by using PLA with digital ASMD readout.

<p>Schematic illustration of protein detection by using PLA with digital ASMD readout.</p