Cloning, overexpression, purification, and characterization of receptor-interacting protein 3 truncation in Escherichia coli

Expression Profile and Tissue-Specific Distribution of the Receptor-Interacting Protein 3 in BALB/c Mice

RIP3, a member of receptor-interacting protein family, is serine/threonine kinase that contributes to necrosis and promotes systematic inflammation. However, detailed information of the expression pattern and tissue distribution in BALB/c mice, a commonly used laboratory animal model, is still unavailable. Here, we provided the basic data of expression profile and histologic distribution of RIP3 in tissues of BALB/c mice. Rip3 mRNA expression levels and tissue distribution were detected by real-time quantitative PCR and immunohistochemical detection, respectively. Rip3 mRNA expression showed the highest level in the spleen and duodenum, while with the lowest level in brain. Immunohistochemical detection revealed this protein located in different type cells in different tissues. What's more, the obvious positive staining in nuclear was detected in liver cells and neurons in cerebral cortex of the brain, while cells in other organs, including heart, spleen, lung, kidney, stomach, duodenum and trachea, showed strong positive mainly in cytoplasm. The results will help us to further understand the site-specific functions of RIP3 in necrosis and inflammatory responses.

High-level expression in Escherichia coli, purification and mosquito-larvicidal activity of the binary toxin from Bacillus sphaericus

The mosquito-larvicidal binary toxin produced by Bacillus sphaericus consists of two polypeptides: BinA and BinB. Both proteins function together, and maximum toxicity is obtained when both are present in equimolar ratio. Cloning and expression of each component separately in heterologous hosts led to low toxicity of the crystal proteins. To improve the expression level, the purification process, and the activity of the binary toxin, the binA and binB genes were separately cloned in Escherichia coli. Each gene was fused in frame to the glutathione S-transferase (GST) gene to be expressed as GST-fusion protein (GST-BinA and GST-BinB). A high expression level was observed from both constructs, and the fusion proteins exhibited high toxicity to Culex quinquefasciatus larvae. High-purity toxin could be obtained by affinity chromatography. The result suggests that GST moiety facilitates high protein production and enables better solubility of the toxin inclusions inside the larval gut, leading to higher toxicity of the fusion protein.