NEDD8 is a member of the ubiquitin-like proteins. The overall structure of NEDD8 is quite similar to ubiquitin. Covalent conjugation of NEDD8 to proteins at the post-translational level is called Neddylation. Neddylation occurs similarly to ubiquitination and need enzyme cascades involving E1, E2 and E3. Neddylation has been demonstrated to be essential to maintain the ubiquitin ligase activity of Cullin-Roc based E3 ligases. Compared with the ubiquitination which was widely studied in the past two decades, few substrates were identified for Neddylation and the physiological functions of Neddylation need further investigations. The current progress of function and regulation of protein Neddylation will be reviewed.

Hepatic Stellate Cells ; Humans ; Liver Cirrhosis

mRNA display provides a new powerful tool for in vitro selecting of peptides and proteins.In the selecting process,peptides are covalently attached to their own mRNA to form mRNA-protein fusions.These mRNA-protein fusions enable in vitro selection of peptide and protein libraries of more than 1013 different sequences.The experiment conditions and protocols have been optimized in recent years.The application of mRNA display technology is mainly in the discovery of ligands for many kinds of target molecules and the analysis and mechanism elucidation on interaction between proteins.With its great potential,there will be a wide application foreground in the application of mRNA display.

Tumor metastasis, the main characteristic of malignance tumor, is the primary cause of death for most cancer patients.The initiation of tumor metastasis involves complex signaling pathway within tumor cell and microenvironment, mediating primary tumor metastasis, invasion, survival and arrest in the blood circulation, and progressive growth at the distant site.The most research on the mechanism of tumor metastais will help understand the metastasis process, and identify promising molecular targets for cancer clinical diagnosis and treatment.

Inhibitor of growth (ING) family proteins belong to candidate tumor suppressor proteins. The ING proteins participate in PtdInsPs-mediated lipid signaling and hormone signaling pathways. They are associated with histone acetyltransferase, histone deacetylase and play a role in chromatin remodeling and gene transcription regulation. ING proteins regulate cell growth, apoptosis and DNA damage repair in p53 dependent manner; thus linking the processes of cell cycle regulation, apoptosis and cellular aging through epigenetic regulation of gene expression.

Animals ; Genomics ; methods ; trends ; Humans ; Proteomics ; methods ; trends ; Publishing ; Research ; trends

Objective To analyze the construction of mouse liver phosphoproteome and phosphorylated kinases to provide useful information for integrating mouse kinase phosphorylation regulatory networks.Methods A new method was established to identify phosphoproteome from the mouse liver.First of all, liver protein was digested with trypsin before the resulting peptides were subjected to a two-step phosphopeptide enrichment and separation procedure consisting of TiO2 chro-maphy enrichment combined with high pHHPLC separation.Samples were injected onto aNanolC-Ultra-2Dplus system cou-pled to an AB-Sciex 5600 Triple TOF mass spectrometer instrument.Then data analysis was performed to provide information of new identified phosphorylation sites of kinase.Results and Conclusion Using our efficient and high-throughput platform, we reported the identification of 5386 phosophorylation sites and 4553 phosphopeptides from 1533 proteins of the mouse liver.126 new phosphorylation sites were identified from 116 kinases, which provides valuable infor-mation for phosphorylation networks in the mouse liver.

Apoptosis action is primarily exerted at the level of mitochondira, in which Bcl-2 family of proteins play an important role in its regulation. Bcl-2 family consists of anti-apoptotic and pro-apoptotic members. The anti-apoptotic members usually exist in the outer mitochondrial membrane and inhibit cell death via interaction with pro-apoptotic counterparts BH3 domain. Pro-apoptotic members are commonly localize in the cytoplasm. A series of events occured, such as typical Bax conformational change, BAD and Bik phosphorylation as well as Bid and Bim proteolysis in response to several death stimuli. As a result, these pro-apoptotic proteins directly integrate to the outer mitochondrial membranes. Finally, mitochondrial permeability transition pore is opened, by followed the release of apoptogenic factors from the mitochondrial intermembrane space, including cytochrome c, apoptosis inducing factor(AIF) and Smac, then the activation of downstream caspases and execution of cell death.

Objective To establish neoplasm transplantation models of breast cancer cells in BALB /c nude mice and to isolate tumor infiltrating myeloid cells.Methods pHAGE-EF-ZsG-DEST plasmid,pMD2.G plasmid and psPAX2 were transfected into BT474 using the method of calcium phosphate transfection .The positive cells were selected by flow cytometry and implanted in the fat pad of nude mice .A tumor model of breast cancer cells implanted in nude mice was constructed, and the tumor infiltrating myeloid cells were isolated .Conclusion Tumor infiltrating myeloid cells are successfully isolated, which will contribute to the study of the functions of tumor infiltrating myeloid cells .

Protein is one of major bio-functional performers. As one of several crucial proteomic research approaches, protein microarray has these following advantages: high-throughput, high sensitivity, quick detection and so on. Meanwhile, there are some critical factors that are important to the further development of protein microarray technology, for example, how to express and purify proteins for the research of protein microarray, how to immobilize proteins onto the substrate and keep the bio-function of proteins immobilized. Nano-biotechnology and cell-free expression system have been used to fabricate protein microarray by the way of immobilizing target genes onto the substrate and directly expressing corresponding proteins, which provides a new strategy to fabricate more complicated microarray. The stragegy and its progress were summarized———fabrication of protein microarray based on DNA, including immobilization of target genes, cell-free expression to proteins, immobilization of renascence proteins, advantages and drawbacks of the methods of protein chip fabrication etc.