抗冻蛋白的作用机制及基因工程研究进展抗冻蛋白的作用机制及基因工程研究进展汪少芸

分析了抗冻蛋白的作用机制及基因工程的研究进展.抗冻蛋白是一类具有热滞效应、冰晶形态效应和重结晶抑制效应的蛋白质.近些年的工作主要集中在该类蛋白质抗冻机制及基因工程的研究上.抗冻蛋白具有广泛的应用前景,它不但可以应用于食物的冷鲜贮存及移植器官的低温保存,还可通过转基因提高经济作物的抗冻能力.     

利用Benford定理分析固有无序蛋白

目的 利用Benford定理分析固有无序蛋白(Intrinsically Disordered Proteins,IDPs).方法 利用本福特定律在生物通路动力学速率常数的成功运用所受到的启发来分析固有无序蛋白.结果与结论 首次系统地调查固有无序蛋白,并发现所有固有无序蛋白及固有无序蛋白的结构域长度首位数的分布都很好地符合本福特定律.因此,固有无序蛋白能做为一个理想的组合来研究实际生活得到的数据的首位数分布,此外,这些观察值还能用来全局地约束固有无序蛋白的行为,这也许能够为固有无序蛋白更加精确的预测提供有用的信息,也将对很多疾病的治疗提供新的思路.     

Divergent effects of hyperosmolality on stress-response (heat shock) protein expression in cultured human tumor cells: an immunocytochemical study

Exposing cells to adverse conditions usually elicits expression of stress-response (heat shock) proteins (srp). Here we show that hyperosmolar growth conditions do not uniformly affect srp expression in MCF-7 and HeLa S3 cells, derived from carcinoma of the breast and cervix, respectively. Thus, whereas srp 27 expression was increased in MCF-7, but not in HeLa S3, the opposite was the case with srp 72. On the other hand, hyperosmolality did not induce B-crystallin or ubiquitin in either cell line. These findings show that srp expression by the human tumor cells studied is non-coordinate, suggesting that each srp is independently modulated.     

Synthesis of a ubiquitously present new HSP60 family protein is enhanced by heat shock only in the Malpighian tubules ofDrosophila

A homologue of the chaperonin protein of the HSP60 family has not been shown so far inDrosophila. Using an antibody specific to HSP60 family protein in Western blotting and immunocytochemistry, we showed that a 64-kDa polypeptide, homologous to the HSP60, is constitutively present in all tissues ofDrosophila melanogaster throughout the life cycle from the freshly laid egg to all embryonic, larval and adult stages. A 64-kDa polypeptide reacting with the same antibody in Western blots is present in all species ofDrosophila examined. Using Western blotting in conjunction with³⁵S-methionine labeling of newly synthesized proteins and immuno-precipitation of the labeled proteins with HSP60-specific antibody, it was shown that synthesis of the 64-kDa homologue of HSP60 is appreciably increased by heat shock only in the Malpighian tubules, which are already known to lack the common HSPs.     

Mitochondrial distribution and inheritance

Mechanisms mediating the inheritance of mitochondria are poorly understood, but recent studies with the yeastsSaccharomyces cerevisiae andSchizosaccharomyces pombe have begun to identify components that facilitate this essential process. These components have been identified through the analysis of conditional yeast mutants that display aberrant mitochondrial distribution at restrictive conditions. The analysis of these mutants has uncovered several novel proteins that are localized either to cytoskeletal structures or to the mitochondria themselves. Many mitochondrial inheritance mutants also show altered mitochondrial morphology and defects in maintenance of the mitochondrial genome. Although some inheritance components and mechanisms appear to function specifically in certain types of cells, other conserved proteins are likely to mediate mitochondrial behavior in all eukaryotic cells.     

二聚体参与真核基因转录调节研究的新进展

本文对蛋白二聚体参与转录调节进行了综述，并较详细地阐述了Ｂ－Ｚｉｐ和Ｂ－ＨＬＨ蛋白的结构特点及功能。     

被子植物雌雄配子及其表膜特异蛋白研究进展

近年来．被子植物雌雄配子的细胞学与生物化学研究取得了一系列重要进展．包括精卵细胞分离纯化、活力保持与检测技术的建立、形态的构观察、生化特性分析及人工体外融合成功，等等．这些进展为创建体外受精操作系统及探讨受精识别机理提供了可能性．被子植物双受精过程存在多位点识别．有关配子水平识别的研究刚刚起步，主要是通过不同途径寻找雌雄配子表膜特异蛋白．其中质膜的纯度与数量问题亟待解决．     

日本沼虾表皮蛋白基因的克隆及表皮组织差异性表达分析

为探究日本沼虾表皮蛋白(Macrobrachium nipponense cuticle proteins,MnCPs)表达模式与表皮组织差异的关系,根据日本沼虾表皮组织转录组测序结果,从头胸甲中克隆到1个含几丁质结合-4(chitin_bind_4)结构域的表皮蛋白(cuticle proteins,CPs)基因,命名为MnCP-2,经BLAST检索,MnCP-2与远海梭子蟹(Portunus pelagicus,ABM54465.1)有50%的相似性.以健康幼虾(体长3.0~4.0cm)的头胸甲、尾扇、游泳足和步足4种厚度存在差异的表皮组织为材料,分别提取C期、D_(0-2)期、D_(3-4)期和A期的RNA,采用Real-time PCR技术,分析了MnCP-2在蜕皮周期不同阶段的相对表达量.结果显示,MnCP-2在头胸甲、尾扇和游泳足中表达水平的峰值出现在D_(3-4)期,而在步足中则出现在D_(0-2)期.提示MnCP-2编码的蛋白可能在新外表皮的形成中发挥重要作用,它在表皮组织不同部位的差异性表达可能是导致表皮结构差异的原因之一.     

果蝇NOMPC相互作用蛋白的筛选与鉴定

NOMPC是果蝇感受触觉的机械力敏感离子通道,属于瞬时受体电位(TRP)离子通道家族,机械力敏感离子通道通过怎样的机制被机械力激活?与NOMPC相互作用的蛋白有哪些?为了研究这些问题,本研究从果蝇NOMPC全长cDNA中扩增得到其N端的29个锚蛋白重复序列(ARs),ORF长度为3 039bp.然后将这29个ARs构建到表达载体pUAST-EGFP上,转染果蝇S2细胞后,通过免疫沉淀、质谱分析和Western blot筛选和鉴定NOMPC相互作用的蛋白,实验筛选出NOMPC N端的29ARs和NOMPC全长的相互作用蛋白,通过免疫共沉淀(Co-IP)实验,对可能与NOMPC存在相互作用的蛋白质进行验证,鉴定出Annexin B9、CG3195、CG3731、CG5374与NOMPC存在相互作用,为进一步研究NOMPC介导触觉转导的分子机制提供了基础.     

Interactions between HMG proteins (HMG1/2 and HMG14/17) and human ε-globin gene promoter (ε-promoter)

High mobility group (HMG) proteins are abundant non-histone proteins in the nuclei of eukaryocytes. It has been shown that HMG proteins may play important roles in the structure and function of chromatin. In the present study, thebinding of HMG proteins (HMG1/2 and HMG14/17) to the human ε-globin gene promoter (ε-promo- ter, -177-+1 bp) has been examined by using both the in vitro nucleosome reconstitution and the electrophoresis mobility shift assay (EMSA). We found that HMG1/2 proteins could bind to the naked ε-promoter DNA, however, HMG14/17 could not. Using the in vitro nucleosome recons- titution, we revealed that HMG14/17 could bind to the mononucleosome reconstituted in vitro with ε-promoter,whi- le HMG1/2 could not. Those results indicate that the binding of HMG proteins to ε-promoter is dynamic as the nucleo- some assembling and disassembling. Wespeculated that this selective binding of HMG proteins to ε-promoter might playa critical role in the regulation of ε-globin gene expression.