Construction of Plasmids Expressing Sars-CoV Encoding Proteins and Their Effects on Transcription of Hfgl2 Prothrombinase

SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expression plasmids, and identify their expression in vitro. Gene fragments encoding N protein, M protein and $2 protein of SARS-CoV were amplified by PCR using cDNA obtained from lung samples of SARS patients as template, and subcloned into pcDNA3.1 vector to form eukaryotic expression plasmids. SARS-CoV protein eukaryotic expression plasmids were transfected respectively into CHO cells. Immunohistochemistry was employed to detect the expression of the structural proteins of SARS-CoV in transfected cells. SARS-CoV protein eukaryotic expression plasmids were successfully constructed by identification with digestion of restriction enzymes and sequencing. M, N and S2 proteins of SARS-CoV were detected in the cytoplasm of transfected CHO cells. It was concluded that these recombinant eukaryotic expression plasmids were constructed successfully, and SARS-CoV encoding proteins could activate transcription and expression of hfgl2 gene.

Identification and Cloning of Resistance Gene Analogues (RGAs) Encoding NBS-LRR Proteins from Gossypium arboreum L.

Plants have developed a complicated defense mechanism during evolution to resist the harmful pathogens they encountered.The mechanism involves the interaction of the plant resistance(R)

Molecular evolutionary analysis of gene families encoding DNA recombination and repair proteins and histone demethylases,and their functional implications

Many eukaryotic genes are members of multi-gene families due to gene duplications, which generate new copies that allow functional divergence. However, the relationship between

Defective Kernel 39 encodes a PPR protein required for seed development in maize

RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)proteins. Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernel size, and seedling lethality. Dek39 encodes an E subclass PPR protein that targets to both mitochondria and chloroplasts, and is involved in RNA editing in mitochondrial NADH dehydrogenase3(nad3) at nad3-247 and nad3-275. C-to-U editing of nad3-275 is not conserved and even lost in Arabidopsis, consistent with the idea that no close DEK39 homologs are present in Arabidopsis. However, the amino acids generated by editing nad3-247 and nad3-275 are highly conserved in many other plant species, and the reductions of editing at these two sites decrease the activity of mitochondria NADH dehydrogenase complex I,indicating that the alteration of amino acid sequence is necessary for Nad3 function. Our results indicate that Dek39 encodes an E sub-class PPR protein that is involved in RNA editing of multiple sites and is necessary for seed development of maize.

Unleashing chemical power from protein sequence space toward genetically encoded “click” chemistry

Synthesis of macromolecular systems with precise structural and functional control constitutes a fundamental challenge for materials science and engineering. Development of the ability to construct complex bio-macromolecular architectures provides a solution to this challenge. The past few years have witnessed the emergence of a new category of peptide-protein chemistry which can covalently stitch together protein]peptide molecules with high specificity under mild physiological conditions. It has thus inspired the concept of genetically encoded click chemistry （GECC）. As a prototype of GECC, SpyTag/ SpyCatcher chemistry has enabled the precise synthesis ofmacromolecules both in vitro and in vivo, exerting precise control over the fundamental properties of these macromolecules including length, sequence, stereochemistry and topology and leading to the creation of diverse biomaterials for a variety of applications. We thus anticipate a potential toolbox of GECC comprising multiple mutually orthogonal, covalent-bond forming peptide-protein reactive pairs with diverse features, which shall bridge synthetic biology and materials science and open up enormous opportunities for biomaterialsin the future.