真核蛋白质的亚细胞位点预测研究进展

研究真核蛋白质的亚细胞位点是了解真核蛋白质功能,深入研究蛋白质相关信号通路内在机制的基础。同时,可以为了解疾病发病机制及为新药研发提供帮助。因此,研究真核蛋白质的亚细胞位点意义十分重大。随着基因组测序的完成,真核蛋白质序列信息增长迅速,为真核蛋白质亚细胞位点的研究提出了更多的挑战。传统的实验法难以满足蛋白质信息量迅速增长的需求。而采用生物信息学手段处理大规模数据的计算预测方法,可在较短时间内获得大量真核蛋白质亚细胞位点信息,弥补了实验法的不足。因此,运用计算预测法预测真核蛋白质的亚细胞位点成为生物信息学领域的研究热点之一。本文主要从提取真核蛋白质的特征信息、计算预测方法及预测效果的评价三个方面,介绍近年来真核蛋白质亚细胞位点预测的研究进展。

真核翻译因子与蛋白质生物合成

真核mRNA在80S核糖体上翻译成蛋白质是一个复杂的过程,需要多步反应及多种因子参与,文章就真核蛋白质的生物合成机制简要综述翻译起始、延伸和终止因子的结构、功能和性质及其在肽链合成过程中的作用研究新进展.

Eukaryotic expression of outer membrane protein Gpd from Treponema pallidum and preliminary studies on its immune response in rabbits

The Gpd gene was amplified from the genomic DNA of Treponema the appropriate site of pcDNA3.1 （ ＋ ） vector. The expression of pcDNA3. I was tested with Western blotting and technology of immunoeytochemisty. New munized with the eukaryotic expression recombinant pcDNA3, 1 （ ＋ ）-Gpd pallidum and cloned into （ ＋ ）-Gpd in Hel,a cells Zealand rabbits were imA fusion protein of C, pd with 4.1 kDa has been effectively expressed in HeLa cells, which were detected bv Western blotting and the immunocytochemistry techniques. The New Zealand rabbits were able to elicit the specific antibody after immunization with the nucleic acid vaccine. The antibody titer could reach as high as 1 ： 1024 after 2 weeks of the third injection; and the splenocytes proliferated evidently due to the Gpd protein stimulation. Both the antibody titer and the splenocytes proliferation were higher substantially than those of controls （ P 〈 0.01 ）. All above data will contribute to an experimental basis of further study of the biological function of Gpd protein as well as DNA vaccine for syphilis.

Archaeal chromatin proteins

Archaea, along with Bacteria and Eukarya, are the three domains of life. In all living cells, chromatin proteins serve a crucial role in maintaining the integrity of the structure and function of the genome. An array of small, abundant and basic DNA-binding proteins, considered candidates for chromatin proteins, has been isolated from the Euryarchaeota and the Crenarchaeota, the two major phyla in Archaea. While most euryarchaea encode proteins resembling eukaryotic histories, crenarchaea appear to synthesize a number of unique DNA-binding proteins likely involved in chromosomal organization. Several of these proteins （e.g., archaeal histones, Sacl0b homologs, Sul7d, Cren7, CC1, etc.） have been extensively studied. However, whether they are chromatin proteins and how they function in vivo remain to be fully understood. Future investiga- tion of archaeal chromatin proteins will lead to a better understanding of chromosomal organization and gene expression in Archaea and provide valuable information on the evolution of DNA packaging in cellular life.

Labeling of human insulin-like growth factor-I eukaryotic expression vector with green fluorescent protein

Objective: To label human insulin-like growth factor-I （hIGF-I） eukaryotic expression vector with green fluorescent protein （GFP） for the repair of articular cartilage defects. Methods: GFP cDNA was inserted into pcDNA3.1-hIGF-1 to construct the co-expression vector with two multiple cloning sites mammalian expression vector under two cytomegalovirus promoters/enhancers respectively. Recombinant pcGI was transfected into NIH 3T3 cells with the help of lipofectamine. Results: Enzyme digestion and agarose gel electrophoresis analysis revealed that pcGI vector contained correct GFP and hIGF-I cDNA. Expression of （hIGF-1） and GFP was confirmed in transfected NIH 3T3 cells by immunocytochemical analysis and fluorescence microscopy. Conclusions: hIGF-I eukaryotic expression vector has been successfully labeled with GFP.

Long noncoding RNAs as Organizers of Nuclear Architecture

In the eukaryotic cell nucleus, chromatin and its associated macromolecules must be organized into a higher-ordered conformation to function normally. However, mechanisms underlying the organization and dynamics of the nucleus remain unclear. Long noncoding RNAs(lnc RNAs), i.e., transcripts longer than 200 nucleotides with little or no protein-coding capacity, are increasingly recognized as important regulators in diverse biological processes. Recent studies have shown that some lnc RNAs are involved in various aspects of genome organization, including the facilitation of chromosomal interactions and establishment of nuclear bodies, suggesting that lnc RNAs act as general organizers of the nuclear architecture. Here, we discuss recent advances in this emerging and intriguing field.

Functions of chromatin remodeling factors in heterochromatin formation and maintenance

Heterochromatin is characteristically more compact than chromatin is mediated by special histone modifications, euchromatin in the eukaryotic genome. The establishment of hetero- recruitment and propagation of heterochromatin specific proteins, as well as formation of special primary and high order structures of chromatin. Chromatin remodeling factors are ATPases that can alter the conformation and/or positioning of nucleosomes along DNA in an ATP-dependent manner. There is increasing evidence implicating chromatin remodeling activities in heterochromatin in various organisms ranging from yeasts to humans. Chromatin remodeling factors play roles in the establishment, maintenance and epigenetic inheritance of heterochromatin, but the underlying molecular mechanisms have just begun to be investigated.