Protein P37 of mycoplasma hyorhinis induces secretion of TNF-α from human peripheral blood mononuclear cells

High mycoplasmal infection ratio in gastric cancer tissues suggests a possible association between my-coplasma infection and tumorigenesis.Because TNF-α plays an important role in carcinogenesis caused by microbes in-fection and P37 is a major immunogen of mycoplasma hy-orhinis(M.hyor.),investigating whether P37 could induce expression and secretion of TNF-α will be very significant fo elucidate the possible molecular mechanism of gastric car-cinogenesis involved with M.hyor.At the present study,we cloned full gene of p37 by PCR and mutated the 7 codes of TGA into TGG firstly,then expressed the P37 protein suc-cessfully with pGEX-4T-1 vector in E.coli,which was veri-fied with Western bolt.By RT-PCR and sensitive L929 cell toxic assay,we found that P37 protein could induce expres-sion and secretion of TNF-α from human peripheral blood mononuclear cells,and the inducing activity of P37 could be dramatically blocked by McAb PD4.These results suggest that the induction of TNF-α secretion by P37 probably plays an importan role in diseases caused by M.hyor.infection and needs to be further investigated.     

HMM in predicting protein secondary structure

We introduced a new method—duration Hidden Markov Model (dHMM) to predicate the secondary structure of Protein. In our study, we divide the basic second structure of protein into three parts: H (α-Helix), E (β-sheet) and O (others, include coil and turn). HMM is a kind of probabilistic model which more thinking of the interaction between adjacent amino acids (these interaction were represented by transmit probability), and we use genetic algorithm to determine the model parameters. After improving on the model and fixed on the parameters of the model, we write a program HMMPS. Our example shows that HMM is a nice method for protein secondary structure prediction. Foundation item: Supported by the National Natural Science Foundation of China (30170214) Biography: Huang Jing (1977-), female, Master candidate, research direction: bioinformatics.     

Inhibitory effect of the adenovirus type 5 E1A protein expressed in the yeast system on the human tumor cell growth

Adenovirus 5 type E1A as a tumor suppressor gene can inhibit tumor growth and enhance the sensitivity of chemotherapy and radiotherapy. E1A have the ability to integrate into the host genome, resulting in long-time expression that induces Rb gene inactivation and animal cells immortalization. This prompted us to select the E1A protein for treatment of cancer in order to overcome the limitations of E1A gene therapy. Thus, we firstly constructed E1A eucaryotic expression vector (pPIC9/E1A), transformated the pichia pastoris yeast cells (GS115) and screened the high-expressing recombinant strains. The positive yeast strains were cultured in the shake flask, and induced for 3 d. The crude E1A protein was purified using two steps of column chromatography on HiTrap Q and HiTrap SP. The purified E1A protein was identified by SDS-PAGE and Western blot. E1A protein was mostly located at cellular nuclear when Chariot delivered E1A protein into cells. The analysis in vitro indicated that the E1A protein arrested LN686 cell cycle at G2/M phase, and significantly inhibited the growth of LN686 tumor cells. The current studies firstly provided an experimental basis to further develop E1A protein for tumor treatment.     

Identification and characterization of a salt tolerance-responsive gene( AtGRP9) of Arabidopsis

Soil salinity is one of the important limiting factors for plant growth and development. A cDNA clone encoding a glycine-rich protein (designated AtGRP9) was identified from Arabidopsis by functional expression of the plant cDNA library in the fission yeast S. pombe. Yeast cells overexpressing AtGRP9 displayed significantly enhanced salt tolerance. Northern analysis showed that expression of AtGRP9 in Arabidopsis was induced by NaCl and plant hormone abscisic acid (ABA). These results suggest that AtGRP9 may be involved in the salt stress response in Arabidopsis.     

Heterotrimeric G protein participated in modulation of cytoplasmic calcium concentration in pollen cells

Cytoplasmic free calcium concentration([Ca2+]c) in pollen cells of Lilium daviddi is measured with confocal laser scanning microscopy to investigate the effect of heterotrimeric G protein (G protein) on [Ca2+]c and the possible signal transduction pathway of G protein triggering cellular calcium signal. After application, cholera toxin (CTX), an agonist of G protein, triggers a transient increase of [Ca2+]c in pollen cells, and evokes a spatial-temporal characteristic calcium dynamics; while pertussis toxin (PTX), a G protein antagonist, leads to the decrease of [Ca2+]c. Both L-type Ca2+ channel blocker verapamil and inhibitor of IP3 receptor heparin inhibit CTX-induced [Ca2+]c increase. The results show that G protein may play a role in the modulation of [Ca2+]c through enhancing the extracellular Ca2+ influx and releasing of Ca2+ from intracellular stores.     

Bioinformatics analysis of SARS-Cov M protein provides information for vaccine development

Severalmonthsago ,anoutbreakofsevereacuterespiratorysyndrome (SARS )startedtospreadaroundtheworld .Asofthiswriting (May 14 ,2 0 0 3) ,morethan 75 0 0 personshavebeeninfectedinasmanyas 2 9countries[1] .The pathogencausingSARShasalreadybeenidentifiedtobeSARS Covbyanumberoflaboratoriesworldwide[2 ,3] .Severedis easesinanimals ,suchasthediseasescausedbyporcinetransmissiblegastroenteritisvirus (TGEV ) ,murinehepatitisvirus (MHV)andporcinehemagglu tinatingencephalomyelitisvirus (PHEV ) ,ha…     

诸葛菜(Orychophragmus violaceus)Toc33基因编码区的克隆及序列分析

以诸葛菜（Orychophragmus violaceus）新鲜嫩叶为材料提取总DNA，并以其为模板，根据已报道的拟南芥（Arabidopsis thaliana）Toc33基因的编码序列，设计一对PCR引物，扩增诸葛菜叶 本外膜蛋白转运器构件蛋白基因Toc33，得到两条扩增带，将这两条带分别割胶回收，与T载体连接转化E.coli，筛选重组子并测序，结果表明克隆到的这两个片段分别长1475bp，1573bp，通过同源性比较发现，它们之间的同源性达到88％，这两个片段与拟南芥Toc33基因有较高的同源性，分别命名为OvToc33-1,OvToc33-2。参考拟介Toc33外显子和氨基酸序列，分别确定了所克隆的两信诸葛菜Toc33基因片段的7个外显子和6个内含子，得到了诸葛菜Toc33基因的全编码区序列，并推导了其氨基酸序列，这两个DNA序列与拟南芥Toc33基因编码区的同源性分别高达91.8%和92.4%，说明这一蛋白是高度保守的。     

一氧化氮的细胞内信号转导

从多个方面对一氧化氮(NO)的细胞内信号转导途径进行了阐述。     

云南沙棘种子蛋白谱带多样性分析

利用聚丙烯酰胺凝胶电泳对云南沙棘 4个居群的 2 9个个体种子蛋白谱带进行了分析 ,结果表明 :云南沙棘在蛋白质水平居群间差异较明显 ,在居群内个体间变异程度不同 ,居群 1,2个体间变异较明显 ,居群 3完全一致 ,居群 4变异程度较低 .变异成因与其生境和鸟、兽远距离传播种子有关 .蛋白质层次的变异很可能也是云南沙棘居群间和居群内形态变异的基础 .     

FHIT在肺癌中的表达与细胞凋亡相关性的研究

目的:探讨脆性组氨酸三联体基因(FHIT)在肺癌中表达情况以及与肺癌细胞凋亡相关性.方法: 利用组织芯片和免疫组织化学技术,检测110例肺癌及25例良性病变的肺组织标本FHIT基因蛋白表达, 并运用脱氧核糖核苷酸末端转移酶介导的缺口末端标记技术(TUNEL)检测肺癌细胞凋亡.结果:1 良性病( ) 变的肺组织FHIT基因异常表达率为16%,肺癌组织异常表达率为85.5%,二者比较,差异有极显著性( =49.390,2P = 0.000); 2 肺癌FHIT基因表达与肺癌细胞凋亡指数(AI)存在显著性差异2= 23.326, = 0.006),且FHIT P基因表达与AI正相关( =0.452, P = 0.000).结论:FHIT基因可能参与肿瘤细胞凋亡的调节, FHIT基因表达下 降可能与肺癌的发生密切相关.