鸡卵泡膜细胞中膜联蛋白A2互作细胞蛋白的筛选及其功能分析

【目的】从鸡卵泡膜细胞蛋白中筛选和鉴定与膜联蛋白A2(ANXA2)相互作用的细胞蛋白并进行功能分析,为深入研究ANXA2调控鸡卵泡发育的作用机制提供理论依据。【方法】制备开产后30周龄贵州黄鸡的卵泡膜细胞,提取卵泡膜总蛋白后利用His Pull-Down联合质谱技术(LC-MS/MS)从卵泡膜细胞中筛选出与鸡ANXA2互作的细胞蛋白,然后通过GO数据库和KEEG数据库分别进行GO功能富集分析及KEEG信号通路注释分析,并利用STRING Version 11.0绘制蛋白互作网络图。【结果】通过His Pull-Down联合LC-MS/MS共鉴定获得41个鸡ANXA2互作细胞蛋白,GO功能富集分析发现这些互作细胞蛋白在分子功能、生物学进程和细胞组成均发挥作用。其中,在分子功能方面主要涉及蛋白结合(占58.06%)、催化活性(占19.35%)、核糖体结构(占16.13%)及细胞骨架结构组成(占6.45%),在生物学进程方面主要参与细胞骨架(占19.35%)、刺激反应(占19.35%)、翻译(占16.13%)、代谢过程(占12.90%)、细胞迁移(占12.90%)、蛋白折叠(占9.68%)和蛋白运输(占9.68%),而细胞组分显示以定位于细胞膜的蛋白为主(占32.26%)。鸡ANXA2蛋白互作细胞蛋白参与的KEEG信号通路主要有应激反应、代谢、翻译、信号转导、免疫系统和蛋白定位等。鸡ANXA2互作细胞蛋白互作网络可分为3条,即CNN2-FN1-MYH9-MYH10-ACTN1-CSRP1、ANXA1-ANXA2-ENO1-PRDX4-GPI-ATP5B-PRDX3-HSPA8-TUBB2A和CCT7-CCT4-GNB2L1-ATP5A1-RPS3-RPS3A-RPL23A-RPL22-RPS7;互作细胞蛋白间存在复杂的互作关系,其中又以膜联蛋白A1(ANXA1)与烯醇化酶-1(ENO1)及ANXA2的互作关系最明显。【结论】鸡ANXA2互作细胞蛋白主要参与细胞骨架形成、应对刺激和翻译等生物学过程,涉及应激反应、代谢、翻译、信号转导、免疫及蛋白定位等信号通路。其中,PRDX3、PRDX4、MYH9和TCSC可能通过与ANXA2蛋白相互作用而参与鸡卵巢相关疾病的发生,而ANXA1与ANXA2相互作用可能在鸡卵泡的发育及排卵过程中发挥重要调节作用。

PCV2复制起始区DNA互作蛋白的筛选及PARP1蛋白对病毒复制的调控

旨在筛选PK-15细胞中与猪圆环病毒2型(porcinecircovirustype2,PCV2)复制起始区(originofreplication,Ori)互作的细胞蛋白谱,并初步探究PARP1蛋白对PCV2复制的调控。利用DNA-proteinpulldown结合LC-MS/MS方法筛选PCV2复制起始区DNA互作蛋白;对互作蛋白进行GO分析以及KEGG通路富集分析,并绘制蛋白互作网络图。在对互作蛋白进行分析的基础上,选择聚(ADP-核糖)聚合酶1(PARP1)蛋白,开展了深入研究。构建了PARP1蛋白以及PCV2复制蛋白Rep真核表达质粒,并利用DNA-proteinpulldown及DNAIP试验验证PARP1蛋白与PCV2Ori的互作;通过Co-IP试验,研究了PARP1蛋白与PCV2Rep蛋白的互作;在细胞中过表达或沉默PARP1蛋白,通过qPCR方法检测对PCV2复制的影响。本研究共鉴定到130种可能与Ori互作的宿主蛋白,其中,与DNA功能相关的蛋白共有45种,主要涉及宿主DNA损伤修复及DNA复制功能;验证了PARP1蛋白与PCV2基因组Ori以及Rep蛋白互作。用siRNA沉默PARP1蛋白表达后,PCV2基因组复制效率显著下降,瞬时过表达PARP1蛋白,PCV2基因组复制效率显著提高。综上所述,本研究筛选到130种可能与PCV2Ori互作的细胞蛋白,发现PARP1蛋白可结合PCV2基因组Ori及Rep蛋白并促进PCV2的复制,为PCV2药物靶点选择及PCV2复制起始过程研究奠定了基础。

Fluorescence Study on The Interaction Between Cisplatinand Erythrocyte Membrane Proteins

The interaction between cisplatin and erythrocyte membrane proteins was studied based on the quenching effect of cisplatin on the intrinsic fluorescence of proteins.A concentration-dependent quenching effect was observed.The presence of chloride and sulphate weakens the effect significantly.A pH-dependence was also noted with a stronger effect in acidic solution. The nature of the interaction is considered to be platinum-thiol group binding according to the effect of cisplatin on the fluorescence of FMA labeled membrane. The mechanism of the cisplatin-protein interactions was discussed based on the effect of coexisting anion

How the Bcl-2 family of proteins interact to regulate apoptosis

Commitment of cells to apoptosis is governed largely by protein-protein interactions between members of the Bcl-2 protein family. Its three sub-families have distinct roles： the BH3-only proteins trigger apoptosis by binding via their BH3 domain to pro-survival relatives, while the pro-apoptotic Bax and Bak have an essential downstream role involving disruption of organellar membranes and induction of caspase activation. The BH3-only proteins act as damage sensors, held inert until their activation by stress signals. Once activated, they were thought to bind promiscuously to pro-survival protein targets but unexpected selectivity has recently emerged from analysis of their interactions. Some BH3-only proteins also bind to Bax and Bak. Whether Bax and Bak are activated directly by these BH3-only proteins, or indirectly as a consequence of BH3-only proteins neutralizing their pro-survival targets is the subject of intense debate. Regardless of this, a detailed understanding of the interactions between family members, which are often selective, has notable implications for designing anti-cancer drugs to target the Bcl-2 family.

The interaction of versican with its binding partners

Versican belongs to the family of the large aggregating chondroitin sulfate proteoglycans located primarily within the extracellular matrix （ECM）. Versican, like other members of its family, has unique N- and C-terminal globular regions, each with multiple motifs. A large glycosaminoglycan-binding region lies between them. This review will begin by outlining these structures, in the context of ECM proteoglycans. The diverse binding partners afforded to versican by virtue of its modular design will then be examined. These include ECM components, such as hyaluronan, type Ⅰ collagen, tenascin-R, fibulin-1, and -2, fibrillin-1, fibronectin, P- and L-selectins, and chemokines. Versican also binds to the cell surface proteins CD44, integrin β1, epidermal growth factor receptor, and P-selectin glycoprotein ligand-1. These multiple interactors play important roles in cell behaviour, and the roles of versican in modulating such processes are discussed.

Identification of the Interaction between P-Glycoprotein and Anxa2 in Multidrug-resistant Human Breast Cancer Cells

Objective To explore the interaction of Anxa2 with P-Glycoprotein （P-gp） in the migration and invasion of the multidrug-resistant （MDR） human breast cancer cell line MCF-7/ADR. Methods A pair of short hairpin RNA （shRNA） targeting P-gp was transfected into MCF-7/ADR cells, and monoclonal cell strains were screened. The expression of P-gp was detected by Western blot. Transwell chambers were used to observe the cell migration capacity and invasion ability. The interaction between P-gp and Anxa2 was examined by immunoprecipitation and immunofluorescence confocal microscopy analyses. Results P-gp expression was significantly knocked down, and there were notable decreasing trends in the migration and invasion capability of MDR breast cancer cells （P〈0.05）. There was a close interaction between Anxa2 and P-gp. Conclusions MCF-7/ADR is an MDR human breast cancer cell line with high migration and invasion abilities. The knockdown of P-gp notably impaired the migration and invasion abilities of the tumor cells. The interaction of Anxa2 with P-pg may play an important role in time enhanced invasiveness of MDR human breast cancer cells.

Cellular Response to Irradiation

To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions. It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

Interplay among cellular polarization,lipoprotein metabolism and hepatitis C virus entry

Hepatitis C virus (HCV) infects more than three million new individuals worldwide each year. In a high percent age of patients, acute infections become chronic, eventually progressing to fibrosis, cirrhosis, and hepatocellular carcinoma. Given the lack of effective prophylactic or therapeutic vaccines, and the limited sustained virological response rates to current therapies, new approaches are needed to prevent, control, and clear HCV infection.Entry into the host cell, being the first step of the viral cycle, is a potential target for the design of new antiviral compounds. Despite the recent discovery of the tight junction-associated proteins claudin-1 and occludin as HCV co-receptors, which is an important step towards the understanding of HCV entry, the precise mechanisms are still largely unknown. In addition, increasing evidence indicates that tools that are broadly employed to study HCV infection do not accurately reflect the real process in terms of viral particle composition and host cell phenotype. Thus, systems that more closely mimic natural infection are urgently required to elucidate the mechanisms of HCV entry, which will in turn help to design antiviral strategies against this part of the infection process.

Host Cell Protein C9orf9 Promotes Viral Proliferation via Interaction with HSV-1 UL25 Protein

In light of the scarcity of reports on the interaction between HSV-1 nucleocapsid protein UL25 and its host cell proteins,the purpose of this study is to use yeast two-hybrid screening to search for cellular proteins that can interact with the UL25 protein.C9orf69,a protein of unknown function was identified.The interaction between the two proteins under physiological conditions was also confirmed by biological experiments including co-localization by fluorescence and immunoprecipitation.A preliminary study of the function of C9orf69 showed that it promotes viral proliferation.Further studies showed that C9orf69 did not influence viral multiplication efficiency by transcriptional regulation of viral genes,but indirectly promoted proliferation via interaction with UL25.

A Multiple Functional Protein:the Herpes Simplex Virus Type 1 Tegument Protein VP22

The herpes simplex virus type 1 （HSV-1） VP22, is one of the most abundant HSV-I tegument proteins with an average stoichiometry of 2 400 copies per virion and conserved among alphaherpesvirinae. Many functions are attributed to VP22, including nuclear localization, chromatin binding, microtubule binding, induction ofmicrotubule reorganization, intercellular transport, interaction with cellular proteins, such as template activating VP16, pU factor I （TAF-I） and nonmuscle myosin II A （NMIIA）, and viral proteins including pUS9 and pUL46, glycoprotein E （gE） and gD. Recently, many novel functions perform tegument protein ed by the HSV-1 VP22 protein have been shown, including promotion of protein synthesis at late times in infection, accumulation of a subset of viral mRNAs at early times in infection and possible transcriptional regulation function .

Mechanisms and Effects on HBV Replication of the Interaction between HBV Core Protein and Cellular Filamin B

Hepatitis B virus(HBV) infection is one of the major problems that threatens global health. There have been many studies on HBV, but the relationship between HBV and host factors is largely unexplored and more studies are needed to clarify these interactions. Filamin B is an actin-binding protein that acts as a cytoskeleton protein, and it is involved in cell development and several signaling pathways. In this study, we showed that filamin B interacted with HBV core protein,and the interaction promoted HBV replication. The interaction between filamin B and core protein was observed in HEK293T, Huh7 and HepG2 cell lines by co-immunoprecipitation and co-localization immnofluoresence. Overexpression of filamin B increased the levels of HBV total RNAs and pre-genome RNA(pg RNA), and improved the secretion level of hepatitis B surface antigen(HBsAg) and hepatitis B e antigen(HBeAg). In contrast, filamin B knockdown inhibited HBV replication, decreased the level of HBV total RNAs and pgRNA, and reduced the secretion level of HBsAg and HBeAg. In addition, we found that filamin B and core protein may interact with each other via four blocks of argentine residues at the C-terminus of core protein. In conclusion, we identify filamin B as a novel host factor that can interact with core protein to promote HBV replication in hepatocytes. Our study provides new insights into the relationship between HBV and host factors and may provide new strategies for the treatment of HBV infection.

A cellular response protein induced during HSV-1 infection inhibits viral replication by interacting with ATF5

Studies of herpes simplex virus type 1 （HSV-1） infection have shown that many known and unknown cellular molecules in- volved in viral proliferation are up-regulated following HSV-1 infection. In this study, using two-dimensional polyacrylamide gel electrophoresis, we found that the expression of the HSV-1 infection response repressive protein （HIRRP, GI 16552881） was up-regulated in human L02 cells infected with HSV-1. HIRRP, an unknown protein, was initially localized in the cytoplasm and then translocated into the nucleus of HSV-l-infected cells. Further analysis showed that HIRRP represses HSV-1 proliferation by inhibiting transcription of the viral genome by interacting with the cellular transcription factor, ATFS, via its N-terminal domain. ATF5 represses the transcription of many host genes but can also act as an activator of genes containing a specific motif. We found that ATF5 promotes the proliferation of HSV-1 via a potential mechanism by which ATF5 enhances the transcription of viral genes during the course of an HSV-1 infection; HIRRP then induces feedback repression of this tran- scription by interacting with ATFS.

A CIB1-LIKE transcription factor GmC IL10 from soybean positively regulates plant flowering

CRYPTOCHROME-INTERACTING basic helix-loop-helix 1(CIB1) is a well characterized transcriptional factor which promotes flowering through the physical interaction with the blue light receptor CRYPTOCHROME 2(CRY2) in Arabidopsis. However, the role of its counterpart in crop species remains largely unknown. Here, we describe the isolation and characterization of a CIB1 homolog gene, Glycine max CIB1-LIKE10(GmC IL10), from soybean genome. The m RNA expression of GmC IL10 in the unifoliate leaves shows a diunal rhythm in both long day(LD) and short day(SD) photoperiod, but it only oscillates with a circadian rhythm when the soybean is grown under LDs, indicating that the clock regulation of GmC IL10 transcription is LD photoperiod-dependent. Moreover, its m RNA expression varies in different tissue or organs, influenced by the develpomental stage, implying that GmC IL10 may be involved in the regulation of multiple developmental processes. Similar to CIB1, Gm CIL10 was evident to be a nuclei protein and ectopically expression of GmC IL10 in transgenic Arabidopsis accelerates flowering under both LDs and SDs, implying that CIBs dependent regulation of flowering time is an evolutionarily conserved mechanism in different plant species.

Cytoplasmic dynein:a key player in neurodegenerative and neurodevelopmental diseases

Cytoplasmic dynein is the most important molecular motor driving the movement of a wide range of cargoes towards the minus ends of microtubules.As a molecular motor protein,dynein performs a variety of basic cellular functions including organelle transport and centrosome assembly.In the nervous system,dynein has been demonstrated to be responsible for axonal retrograde transport.Many studies have revealed direct or indirect evidence of dynein in neurodegenerative diseases such as amyotrophic lateral sclerosis,Charcot-Marie-Tooth disease,Alzheimer’s disease,Parkinson’s disease and Huntington’s disease.Among them,a number of mutant proteins involved in various neurodegenerative diseases interact with dynein.Axonal transport disruption is presented as a common feature occurring in neurodegenerative diseases.Dynein heavy chain mutant mice also show features of neurodegenerative diseases.Moreover,defects of dynein-dependent processes such as autophagy or clearance of aggregation-prone proteins are found in most of these diseases.Lines of evidence have also shown that dynein is associated with neurodevelopmental diseases.In this review,we focus on dynein involvement in different neurological diseases and discuss potential underlying mechanisms.

Expression, subcellular localization and protein-protein interaction of four isoforms of EcR/USP in the common cutworm

Ecdysone receptor （EcR） and ultraspiracle （USP） form heterodimers to mediate ecdysteroid signaling during molting and metamorphosis. Various EcR/USP heterodimers have been reported. However, it is unclear what kind of EcR/USP combination is adopted by lepidopteran insects during the larval-pupal metamorphosis and whether the EcR/USP heterodimer varies among different tissues. To address these questions, two isoforms of each EcR and USP were cloned from the common cutworm, their messenger RNA expression patterns were examined by real-time quantitative polymerase chain reaction in different tissues during the larval-pupal metamorphosis and in the midgut in response to hormonal induction. Furthermore, their subcellular localization and protein-protein interaction were explored by transient expression and far-western blotting, respectively. All the four genes were significantly up-regulated in prepuae and/or pupae. The expression profiles of EcRB1 and USP1 were nearly identical to each other in the epidermis, fat body and midgut, and a similar situation also applied to EcRA and USP2. The three genes responded to 20-hydroxyecdysone （20E） induction except for USP2, and USP1 could be up-regulated by both 20E and juvenile hormone. The four proteins mainly localized in the nucleus and the nuclear localization was promoted by 20E. The protein-protein interaction between each EcR and USP was found in vitro. These results suggest that two types of EcR/USP heterodimer （EeRA/USP2 and EcRB 1/USP1） may exist simultaneously in the common cutworm, and the latter should play more important roles during the larval-pupal metamorphosis. In addition, the types of EcR/USP heterodimer do not vary in the tissues which undergo histolysis and regeneration during metamorphosis.

Current advances in the application of proteomics in apoptosis research

Apoptosis,or programmed cell death,is a complex,genetically-determined process involved in the development and maintenance of homeostasis in multicellular organisms.Dysregulation of apoptosis has been implicated in a number of diseases,including cancer and autoimmune disease.Thus,the investigation of apoptotic regulation has evoked considerable interest.Many apoptotic proteins have been shown to be post-translationally modulated,such as by protein cleavage,translocation,protein-protein interaction,and various post-translational modifications,which fall precisely within the range of proteomic analysis.Recently,contemporary proteomic technologies have achieved significant advances and have accelerated research in functional and chemical proteomics,which have been applied to the field of apoptosis research and have the potential to be a driving force for the field.This review highlights some of the major achievements in the application of proteomics in apoptosis research and discusses new directions and challenges for the near future.

Identification of neuron-related genes for cell therapy of neurological disorders by network analysis

Bone mesenchymal stem cells（BMSCs） differentiated into neurons have been widely proposed for use in cell therapy of many neurological disorders. It is therefore important to understand the molecular mechanisms underlying this differentiation. We screened differentially expressed genes between immature neural tissues and untreated BMSCs to identify the genes responsible for neuronal differentiation from BMSCs. GSE68243 gene microarray data of rat BMSCs and GSE18860 gene microarray data of rat neurons were received from the Gene Expression Omnibus database. Transcriptome Analysis Console software showed that 1248 genes were up-regulated and 1273 were down-regulated in neurons compared with BMSCs. Gene Ontology functional enrichment, protein-protein interaction networks, functional modules, and hub genes were analyzed using DAVID, STRING 10, BiN GO tool, and Network Analyzer software, revealing that nine hub genes, Nrcam, Sema3 a, Mapk8, Dlg4, Slit1, Creb1, Ntrk2, Cntn2, and Pax6, may play a pivotal role in neuronal differentiation from BMSCs. Seven genes, Dcx, Nrcam, Sema3 a, Cntn2, Slit1, Ephb1, and Pax6, were shown to be hub nodes within the neuronal development network, while six genes, Fgf2, Tgfβ1, Vegfa, Serpine1, Il6, and Stat1, appeared to play an important role in suppressing neuronal differentiation. However, additional studies are required to confirm these results.