Novel variant of p230 trans-Golgi network protein identified by serum from Sjögren's syndrome patient

Trans-Golgi network (TGN) protein p230 is a peripheral membrane protein associated with the cytoplasmic face of the TGN. TGNp230 is an extensively coiled-coil protein with flexible amino- and carboxyl-terminal ends, associates with non-clathrin-coated vesicles arising from the TGN, and is implicated in vesicle biogenesis. Here we used an autoimmune serum from a patient with S ogren's syndrome to clone partial cDNAs from a human hepatoma HepG2 expression library. The partial cDNAs encoded a novel amino-terminal splice variant of TGNp230. Specific reactivity of the autoimmune serum for p230 is supported by immunofluorescene staining of the Golgi apparatus, immunoblotting of a > 200-kDa HeLa cell protein, and reactivity with a bacterially expressed GST-p230 fusion protein. The alternative splicing occurs within the first proline-rich domain of p230. It comprises a deletion of 30 bp followed immediately by an additional 66 bp absent in the published sequence. RT-PCR analysis indicated that the splicing occurs independently of previously reported carboxyl-terminal splicing, and that this novel splice variant is more frequent than the previously reported p230. The novel splice variant of p230 is also located at the TGN. We propose that p230 splice variants may be implicated in selection of cargo molecules for vesicles arising from the TGN.     

辛伐他汀对动脉粥样硬化大鼠凋亡相关基因Fas及FasL蛋白表达的影响

目的通过研究辛伐他汀对动脉粥样硬化大鼠血管壁中细胞凋亡相关基因Fas及FasL蛋白表达产物的影响,探讨其在预防动脉粥样硬化发生中的可能机制。方法复制动脉粥样硬化大鼠模型,以辛伐他汀干预,取胸主动脉,观察其斑块变化,采用免疫组化Elivision法测定动脉粥样硬化血管壁中Fas、FasL蛋白表达。结果Fas蛋白表达在实验组明显高于对照组及干预组(P<0.01,P<0.05),实验组FasL蛋白表达也明显高于对照组及干预组(P<0.05)。结论Fas及FasL基因通过促进细胞凋亡作用而诱发动脉粥样硬化过程,辛伐他汀可通过调节细胞凋亡过程发挥抗动脉粥样硬化作用。     

免培养法对一热泉细菌多样性的初步研究

应用免培养法（Cultureindependent）对云南腾冲热海大滚锅高温热泉中细菌的多样性进行初步的分析。经过克隆筛选,测定了5个克隆的16S rDNA插入片段的近全序列,系统发育分析的结果表明,它们分属于Bacillus、Hydrogenobacter和Pseudomonas,有一个克隆尚难确定其分类地位,它属于Thermodesulfobacteriaceae科,介于Geothermbacterium属和Thermodesulfobacteria属之间。经PCR扩增出上述5个克隆16S rDNA插入序列中及环境样品总DNA中的16S rDNA V8高变区约600bp片段,进行变性梯度电泳（DGGE）。所得电泳图谱和5个序列的系统发育树不仅表明该高温热泉存在着丰富的细菌多样性,还显示了它们是该高温热泉中细菌的优势物种。     

云南土壤放线菌生态分布的研究

云南具有极为复杂的地理气候。根据云南省不同的地质、地理、土壤、气候、植被特点选择样区,采集土壤样品,研究了云南不同地区、不同生态环境放线菌的生态分布与植被的关系。将云南土壤放线菌区系划分为热带区系、亚热带高原区系、滇西北高山区系和雪山区系四种类型。对云南土壤放线菌区系的特点进行了讨论。     

Functional comparison of metallothioneins MTT1 and MTT2 from Tetrahymena thermophila

Metallothioneins MTT1 and MTT2 from Tetrahymena thermophila have been characterized. The MTT1 contains mainly characteristic Cys-Cys-Cys and Cys-Cys clusters, but MTT2 contains mainly Cys-X-Cys cluster. Cd₁₆-MTT1 mainly consists of α-helix and β-turns, in contrast, Cd₁₁-MTT2 mainly consists of random coils. Reaction of Cd₁₆-MTT1 and Cd₁₁-MTT2 with nitric oxide leads to intramolecular disulfide bond formation, respectively. Binding stabilities of Cd²⁺, Hg²⁺ and Zn²⁺ to MTT1 are stronger than those to MTT2. Cu²⁺ can not replace Cd²⁺ from Cd₁₆-MTT1 complex, but can replace Cd²⁺ from Cd₁₁-MTT2 complex. The analysis of qRT-PCR revealed MTT2 mRNA levels were 31-fold higher than those of MTT1 under basal conditions. These results further suggest MTT1 possibly play a role in the detoxification of heavy metal ions, and MTT2 may be involved in the homeostasis of copper ions.     

Emergence of <Emphasis Type="Italic">Aureobasidium pullulans</Emphasis> as human fungal pathogen and molecular assay for future medical diagnosis

Despite the great importance of Aureobasidium pullulans in biotechnology, the fungus had emerged as an opportunistic human pathogen, especially among immunocompromised patients. Clinical detection of this rare human fungal pathogen presently relies on morphology diagnosis which may be misleading. Thus, a sensitive and accurate quantitative molecular assay for A. pullulans remains lacking. In this study, we presented the microscopy observations of A. pullulans that reveals the phenotypic plasticity of the fungus. A. pullulans-specific primers and molecular beacon probes were designed based on the fungal 18S ribosomal RNA (rRNA) gene. Comparison of two probes with varied quencher chemistry, namely BHQ-1 and Tamra, revealed high amplification efficiency of 104% and 108%, respectively. The optimized quantitative real-time PCR (qPCR) assays could detect and quantify up to 1 pg concentration of A. pullulans DNA. Both assays displayed satisfactory performance parameters at fast thermal cycling mode. The molecular assay has great potential as a molecular diagnosis tool for early detection of fungal infection caused by A. pullulans, which merits future study in clinical diagnosis.     

不同营养条件对东海原甲藻和中肋骨条藻竞争参数的影响

以东海原甲藻和中肋骨条藻为研究对象,采用室内单种培养和混合培养,设置不同的氮、磷营养条件,研究了不同营养条件对两种微藻的生长状况和种间竞争参数的影响.结果表明:随着氮、磷浓度的增加,两种藻的最大生物量均呈增加趋势,混合培养中两种微藻的比生长率低于单独培养.在混合培养中,生长前期中肋骨条藻是优势种,随着培养时间的延长,东海原甲藻成为优势种,且优势种发生变化的时间与营养条件有关.混合培养中,东海原甲藻拐点出现时间在0.5 ～4.9 d,中肋骨条藻为0～2.6d,东海原甲藻拐点出现时间晚于中肋骨条藻.在各营养条件下,东海原甲藻对中肋骨条藻的竞争抑制参数β均高于中肋骨条藻对东海原甲藻的竞争抑制参数α,当N为128μmol·L-1、P为32 μmol·L-1时,东海原甲藻的竞争能力是中肋骨条藻的3.8倍,两者差异最为明显.     

新型表达载体 pEC34 试用于人 γ 干扰素基因的高表达

构建了一个新的双顺反子表达载体ｐＥＣ３４,它的第一个顺反子是已高表达的ｅｒａ基因的部分序列,并带有原核翻译增强子。当检测ｐＥＣ３４的可用性时,获得了人γ－干扰素的极高表达。目的蛋白占菌体总蛋白的８５．５％,诱导后经ＳＤＳ－ＰＡＧＥ分析,出现分子量为１５．５ｋＤａ左右的蛋白表达带。Ｗｅｓｔｅｒｎ ｂｌｏｔ结果证实为人γ－干扰素。无压力传代３０次表达质粒仍然稳定,表明ｐＥＣ３４可能用作真核蛋白质高表达     

小麦HMW-GS1Dx5基因的克隆及其特异性表达

显微切割了普通小麦钢８２－１２２（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍ２ｎ＝４２）具有１Ｄｘ５＋１Ｄｙ１０亚基的１Ｄ染色体长臂端,利用ＰＣＲ扩增得到了ＨＭＷ－ＧＳ１Ｄｘ５亚基的５（端４００ｂｐ序列片段．以此作为探针从基因的组织特异性和特定发育阶段的表达两个方面研究了ＨＭＷ－ＧＳ１Ｄｘ５基因表达的规律．结果表明,干种子及萌发种子中存在此基因,而在发育的幼苗中此基因未表达．ＨＭＷ－ＧＳ１Ｄｘ５基因可能从开花初期开始表达．ＨＭＷ－ＧＳ１Ｄｘ５基因在籽粒成熟期表达,然而在营养器官如叶片中未表达,其表达存在组织特异性．ＨＭＷ－ＧＳ１Ｄｘ５基因在蜡熟期籽粒表达水平最高,其次是乳熟期籽粒．从开花１５ｄ至蜡熟期籽粒,表达趋于增加．开花１５ｄ其ｍＲＮＡ水平是蜡熟期籽粒ｍＲＮＡ的２８％,灌浆期为４０％、乳熟期为７２％、完熟期为５４％．这为进一步研究其表达调控和改善小麦品质打下基础