Phosphoproteome analysis of the human Chang liver cells using SCX and a complementary mass spectrometric strategy

The liver is the largest organ in the body, with many complex, essential functions, such as metabolism, deintoxication, and secretion, often regulated via post-translational modifications, especially phosphorylation. Thus, the detection of phosphoproteins and phosphorylation sites is important to comprehensively explore human liver biological function. The human Chang liver cell line is among the first derived from non-malignant tissue, and its phosphoproteome profile has never been globally analyzed. To develop the complete phosphoproteome and probe the roles of protein phosphorylation in normal human liver, we adopted a shotgun strategy based on strong cation exchange chromatograph, titanium dioxide and LC-MS/MS to isolate and identify phosphorylated proteins. Two types of MS approach, Q-TOF and IT, were used and compared to identify phosphosites from complex protein mixtures of these cells. A total of 1035 phosphorylation sites and 686 phosphorylated peptides were identified from 607 phosphoproteins. A search using the public database of PhosphoSite showed that approximately 344 phosphoproteins and 760 phosphorylation sites appeared to be novel. In addition, N-terminal phosphorylated peptides were a greater fraction of all identified phosphopeptides. With GOfact analysis, we found that most of the identified phosphoproteins are involved in regulating metabolism, consistent with the liver's role as a key metabolic organ.     

FOXO 蛋白的修饰与细胞凋亡和癌变

Fox 蛋白家族是 2000 年才发布统一命名的蛋白质家族 . 由于其在生物体内所起的重要作用,已迅速成为生命科学研究的热点 . 目前,已经发现其家族成员有 100 多种,其中, FOXO 亚家族在动物细胞的凋亡中起重要作用 . 细胞凋亡与动物的长寿、繁殖、代谢、肿瘤发生及免疫有重要关系,对 Forkhead (Fox) 蛋白分子的命名进行了回顾、对其分类与结构特征进行了总结,并重点对 FOXO 的化学修饰、活性调节及其在细胞凋亡和肿瘤发生中的作用进行了综述 .     

家蚕hsp70启动子的克隆及功能研究

该研究通过PCR的方法克隆得到家蚕热激蛋白70基因(Bombyx mori hsp70)的5'侧翼的两个长度分别为538 bp和305 bp的序列hsp70-538和hsp70-305。生物信息分析结果表明这两段序列在TATA序列的上游存在保守的热激元件HSE(heat shock element)CTnGAAnnTTCnAG。采用双荧光报告基因技术研究表明这两段序列在BmN细胞中都表现出热激活性,转基因家蚕实验证明hsp70-305在家蚕个体中也具有热激活性,可以认为这两个片段具有hsp70热激启动子特性。     

生物结皮对3种荒漠草本植物光合生理特性的影响

通过人工去除生物结皮实验,研究古尔班通古特沙漠生物结皮对3种荒漠草本植物生理特性的影响,根据生物结皮对土壤养分和水分的影响,综合分析生物结皮对3种草本植物光合生理特性的影响。结果表明,生物结皮对3种荒漠草本植物光合生理的影响基本一致,在植物生长早期,生物结皮区的尖喙牻牛儿苗（Erodium oxyrrhynchum M.Bieb.）、条叶庭荠（Alyssum linifolium Steph.ex Willd.）和琉苞菊（Hyalea pulchella（Ldb.） C.Koch）的叶片相对含水量（RWC）、净光合速率（P_n）、气孔导度（G_s）、蒸腾速率（E）、水分利用效率（WUE）、PSⅡ最大光化学量子效率（F_v/F_m）、PSⅡ实际光化学效率（φ_PSⅡ）和叶绿素（Chl）含量均高于去除生物结皮区;但是,在植物生长后期,却是去除生物结皮区的各项生理指标高。生物结皮对3种荒漠草本植物光合生理过程的影响与其对植物生长的影响基本一致,这与土壤养分和水分状况的变化密切相关。     

GABA/progesterone-induced polyphosphoinositide (PPI) breakdown and its role in the acrosome reaction of guinea pig spermatozoa in vitro

To investigate whether GABA/progesterone (P4) stimulates PPI breakdown and its role in the acrosome reaction (AR), spermatozoa of guinea pig were preincubated in MCM-LCa2+ for 5.5 h and then labeled with [32P]pi for 1 h. Samples were washed through a three-step gradient Percoll, adjusted to 5×107 cells/mL and exposed to 2 mmol/L Ca2+, 5 mmol/L GABA, 10 mmol/L P4 and other agents. Lipids were separated by t.l.c. and radioactivity in spots determined by scintillation counting. The AR was assessed by phase-contrast microscopy. The results showed that (i) when spermato-zoa were treated with GABA, 32P-label diminished rapidly in phosphatidylinositol 4, 5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP), and increased in phosphatidic acid (PA). The loss of label from PPI was almost completed by 10 min. The time-course of the AR was much slower than PPI when spermatozoa reached a maximal response by 15 min; (ii) the pattern of PPI hydrolysis and stimulation of AR was similar for the three agonists tested；their potency followed the order A23187＞progesterone≥GABA; (iii) GABA-induced PIP2 hydrolysis and rise in PA and the AR were prevented by inclusion of 10 mmol/L neomycin; (iv) the loss of PIP2 labeling and the increase in PA labeling abolished when spermatozoa were exposed to EGTA or Ca2+ channel blocker. These re-sults indicate that GABA or P4-induced PPI breakdown is an important and essential event in the series of changes to membrane fusion during the AR of guinea pig spermatozoa and this effect is mediated via calcium by activation of phosphatidylinositol-specific phospholipase C.     

蓝藻OscilatoriaceaerDNA16S-23S基因间隔区的序列分析及其分类学意义

采用末端终止法对蓝藻类颤藻科Ｏｓｃｉｌａｔｏｒｉａｓｐ．ｒＤＮＡ１６Ｓ－２３Ｓ基因间隔区进行了序列测定,获得了Ｏｓｃｉｌａｔｏｒｉａｓｐ．ｒＤＮＡ基因间隔区４２７个核苷酸,其中包含１个异亮氨酸ｔＲＮＡ基因（ｔＲＮＡＩｌｅ）。并通过计算机联网从国际分子生物学数据弹库中获取颤藻科其它种的ｒＤＮＡ基因间隔区序列,通过比较分析,从分子水平对颤藻科Ｏｓｃｉｌａｔｏｒｉａｃｅａｅ属间的某些分类学问题进行了讨论,并根据序列中核苷酸差异值探讨了颤藻科属间界定的分子标准。提出了ｒＤＮＡ基因间隔区是良好的分子标记,可用于“赤潮”或“水华”蓝藻专一性核酸分子探针的研制     

喀斯特山区土地利用对土壤团聚体有机碳和活性有机碳特征的影响

通过选取喀斯特山区火龙果园、草丛、花椒林、乔木林和灌草丛为研究对象,对其土壤团聚有机碳和团聚体活性有机碳分布与积累特征进行研究,结果表明:各土地利用方式下的团聚体组成均以＞0.5 mm团聚体为主,其含量可占团聚体总量的82.57％-94.79％;各粒级团聚体中有机碳和活性有机碳的含量均以乔木林最高,花椒林和火龙果园相对居中,而以草丛和灌草丛较低,随土壤团聚体粒径降低,有机碳和活性有机碳的峰值基本出现在＜0.25 mm粒级团聚体,但该粒径对土壤有机碳和活性有机碳的贡献率却不足6％和4％;土壤有机碳和活性有机碳的累积均受5-1 mm团聚体中有机碳和活性有机碳含量增加的影响,该粒级团聚体对有机碳和活性有机碳的贡献率也分别达28.70％-49.47％和34.13％-47.47％,可将5-1 mm粒径团聚体作为喀斯特山区的土壤有机碳固定的特征团聚体;土壤团聚体活性有机碳含量与土壤团聚体总有机碳含量呈极显著正相关关系(r=O.8768),表明团聚体活性有机碳可以作为衡量喀斯特山区土壤团聚体有机碳动态的一个敏感性指标.     

甲醇浓度对毕赤酵母表达重组人复合α干扰素分离纯化得率的影响

研究了毕赤酵母Pichia pastoris表达的重组人复合α干扰素(cIFN)时不同诱导甲醇浓度对cIFN分离纯化得率的影响,并分析了原因.在5L罐中采用0.25、0.50和0.75％(W/V)三个甲醇浓度诱导时,在0.75％高甲醇浓度诱导下cIFN表达水平最高,达到2.06 g/L,是0.25％低甲醇浓度诱导的1.24倍,但是低甲醇浓度诱导下cIFN分离纯化得率却高于高甲醇诱导浓度下3.75倍.另外,低甲醇浓度下发酵上清液cIFN抗病毒活性为2.85×108IU/mL,较高甲醇浓度提高了4.48倍.进一步采用SDS-PAGE和Native-PAGE免疫印迹分析不同条件下发酵液中cIFN存在状态,发现在高甲醇浓度下cIFN容易形成大量的聚合体,分别为共价聚合和非共价聚合,而cIFN单体含量较少,但是低甲醇浓度诱导下情况完全相反.最终在0.25％甲醇诱导下分离纯化1L发酵上清液可得0.73 g单体cIFN,是0.75％甲醇诱导下的3.84倍.     

香港三种人工林下植物多样性的调查

报道了作者于1995年6月至19％年1月期间对香港3种人工林－红胶木林、相思树林、荷树及其混交林林下植物区系调查的初步结果。在10个面积为200-400m2的人工林样方中,共记载了184种非栽培的植物种类,它们分属于70个科139属,其中42％的种类是树木,约占香港树木区系的20％。最常见的植物种类通常具有可以被鸟类传播的小型浆果或核果,它们也是天然次生林中的常见种。这些人工林样方的树木多样性（Shannon指数）在0-2．66之间,随着人工林的年龄增长呈增加的趋势。人工林在加速森林植被的恢复和促进退化地区生物多样性的发展中具有重要的作用,特别是植物种源严重贫乏地区森林植被恢复的重要手段。在营造速生人工林时,适当引入鸟播的野生树种,可加速人工林的自然演替速度和提高人工林的生态效益。     

伊犁河谷北坡野果林木本植物种间关系及环境解释

伊犁河谷北坡野果林是天山山脉中一个重要的植被类型,对其种间关系进行研究将有助于揭示野果林群落的动态特征.我们于2009年在野果林的不同群落中设置了10个样地,记录了群落的物种组成以及环境因子,包括海拔、坡度和坡向,测定了土壤含水率和有机质等土壤参数.采用x2检验、Pearson相关系数和Spearman秩相关系数检验等方法,对野果林乔木层和灌木层种间关联性进行了研究.结果表明:Pearson相关检验优于x2检验,Spearman 秩相关检验比Pearson相关检验更加灵敏;乔木和灌木优势种绝大多数种对的联结关系未达到显著水平,群落结构较为松散,表明各群落可能处于演替的早期阶段;在影响物种分布的环境因子中,海拔起决定性的作用,其次是坡向、土壤含水率、有机质、全氮和pH值.