Abstract:Histone phosphorylation is a kind of post-translational modifications，which belongs to the regulation of epigenetics. It was found to play an important role in DNA repair and cell division. In recent years，more and more studies have shown that it also regulates cognitive function such as learning and memory. Here，we reviewed recent findings about the role of histone phosphorylation in learning and memory，as well as the molecular mechanisms for its upstream signal pathways and downstream regulation in transcription to provide new theoretical basis and therapeutic targets at cognitive disorders.

Abstract:Antibody (also named as an immunoglobulin, Ig), a most important macromolecule for immune response in human body, has been developed as macromolecular drug to treat the cancer and immune diseases. Understanding of antibody three-dimensional (3D) structure and fluctuation could be an important step for further understanding and controlling the antibody pharmacological function. However, the study is limited by antibody flexible structure. In this paper, we reviewed the current research progresses on structural study of human IgG1 antibody conducted by our recently developed individual-particle electron tomography (IPET) method. The review includes the sample preparation method, basic logic of image processing strategy, 3D analysis and its application in antibody-drug conjunction and antibody structural fluctuation. We also discussed the strengths and weakness of the technique.

Abstract:There are three classes of viral fusion protein. Different types of viral fusion proteins usually have radically different architectures, whereas they share similar “hairpin” conformation during fusion processes. After triggering, a hydrophobic domain, fusion loop or fusion peptide insert into target membrane and the opposing membrane were brought closely with fusion protein folding and hairpin formation. With the energy from viral fusion protein conformational changes, the membranes were broken and fusion together. Here, we reviewed the characteristics of three classes viral fusion proteins and the functions of central trimer-of-hairpin domain, transmembrane domain and juxtamembrane domain in fusion process.

Abstract:The retromer complex is a multimeric protein complex involved in transporting proteins from endosomes to the trans-Golgi network or plasma membrane. Recent studies show that retromer interplays with many viral proteins to regulate viral life cycle. This review will summarize the interaction between retromer and viruses including HCV, HIV-1, HPV, vaccinia virus and HVS, and will discuss the role of retromer in virus infection.

Abstract:Ubiquitylation is involved in most part of cellular processes, including protein degradation, autophagy, DNA damage repair, cell cycle, signaling transduction, gene expression, transcription regulation, inflammation and immune response. Instead of the formation of ubiquitylation, deubiquitinating enzymes (DUBs) hydrolyze monoubiquitylation and polyubiquitylation of substrates in response to ubiquitin-mediated pathways. There exits approximately 90 DUBs in human genome which regulate the enzymatic activity and recognition of substrates to control with precision the multi-layer complex cellular ubiquitin network. DUBs play diverse roles in cellular process, their dysfunctions direct to many serious diseases (like cancers, neurodegenerative disorders and infection diseases). Therefore, DUBs represent novel candidates for target-directed drug development. However, many physiologic functions of DUBs are still unknown. Whether they recognize different polyubiquitin chains and how to response signaling transduction accurately are unlear. In this review, we systematically surveyed the selectivity of the DUBs that we have known in hydrolyzing different ubiquitin chains and their mechanisms.

Abstract:Fragile X syndrome(FXS) is the most common inherited cognitive disorder, and is also a kind of severe gene diseases associating with autism spectrum disorders (ASDs). It is principally caused by the abnormal amplification of fragile X mental retardation gene 1 (FMR1) and abnormal methylation of CpG island on its upstream, then leading to the reduction or deficiency of its protein product fragile X mental retardation protein (FMRP). Both FMRP and miRNA have transcriptional repression activity, and FMRP was related to miRNA regulation pathway in the biochemical and genetic. In addition, more and more studies showed that miRNA regulation pathway plays a role in the synthesis and translation regulation of miRNA. In this review, the role of miRNA in the pathogenesis and treatment of FXS. Thus in this paper, we described the functions of miRNA and its interaction with the fragile X protein family members, laying the foundation for understanding the nosogenesis of FXS at the level of miRNA.

Abstract:The effects of 17-day spaceflight microgravity on the photosynthetic activity of Euglena gracilis were investigated during the SIMBOX mission on board the Chinese Shenzhou-8 spacecraft. We found that microgravity decreased Fv/Fm, while chlorophyll a and carotenoid contents were increased. The fluorescence yields were clearly reduced by microgravity, but the shape of fluorescence transients (O-J-I-P) was not changed. The quantum yield of primary photochemistry (φPo), the quantum yield of electron transport (φEo) and the performance index of PSⅡ(PI_ABS and PI_CS) in microgravity group were decreased, while ABS/RC and DIo/RC were increased. 77K fluorescence emission spectra indicated that microgravity altered energy distribution between PSⅡ and PSⅠ and there are redshifts under microgravity. These results suggested that microgravity may impair photosynthesis by inhibition of acceptor sides of PSⅡ in electron transfer pathway and alter PSⅠ structure to cause a reduction of energy transfer to PSⅠ in Euglena gracilis.

Abstract:Our previous work has demonstrated that ultrafiltration has the potential for the isolation of photosystem Ⅰ(PSⅠ) from spinach at a large scale. In order to develop a practical bioseparation process, the “product” and the “impurity” should be characterized in order to choose suitable membrane and optimize the operational and physiochemical parameters. One easily adjusted but critically important parameter, the solution ionic strength, and its effects on the properties of target protein (PSⅠ) and the major impurity (photosystem Ⅱ, PSⅡ) were studied. Following the isolation of PSⅠ and PSⅡ from spinach, the aggregation size, zeta potential, atomic force microscopy imaging and thermal stability were determined. Solution ionic strength was found to have a significant influence on the activity, aggregation size and thermal stability of both PSⅠ and PSⅡ. The results also demonstrated that the “molecular sieve effect” played a central role in the newly developed ultrafiltration process for PSⅠ isolation.

Abstract:Valproic acid (VPA) is a histone deacetylase inhibitor that has been an object of interest to clinicians for its promising potency in cancer therapy, as it induces apoptosis and differentiation, and enhances of chemotherapy sensitivity. Esophageal squamous cell carcinoma (ESCC) is a malignant disease with growing incidence and low survival rate. Due to limited information on VPA activity in ESCC cells, we aimed to determine effects of VPA on chemotherapy responsiveness and expression of malignant markers in ESCC stem-like cells. Upon coadministration of non-toxic VPA + cisplatin (DDP), paclitaxel and 5-fluorouracil, viability of KYSE30 cells was assessed, and induced apoptosis was evaluated by DAPI staining, DNA laddering and flow cytometry. In addition, real time RT-PCR was performed to study changes in the expression of P21, CD44 and BMI-1 upon treatments. MTT test demonstrated that VPA significantly (P < 0.05) increased toxicity of DDP, which was confirmed by DNA laddering, flow cytometry analysis and significant (P < 0.05) overexpression of P21. Moreover, real time RT-PCR results indicated significant (P < 0.05) down regulation of CD44 and BMI-1 after VPA administration. Present attempt provided evidence, for the first time, that VPA not only improved responsiveness of esophageal stem-like cancer cells to DDP, also negatively regulated cancer stem cells markers in these cells.

Abstract:Glycosylation is one of the most common and important post-translational modifications(PTMs) of proteins in living organisms. More than 50% proteins are glycosylated among mammals. Glycoproteins are widely distributed in cell membrane surface and body fluids, and play critical roles in biological processes. With the rapid development of biological mass spectrometry technique, as well as biological database and analysis software for glycan structure elucidation, glycoproteomics research field is booming soon. This article summarized the most commonly used bioinformatic resources in literatures, including new developed databases, MS technique and methods.