Post-translational modifications of protein in response to ionizing radiation

Based on central dogma of genetics, protein is the embodiment and executor of genetic function, post-translational modifications (PTMs) of protein are particularly important and involved in almost all aspects of cell biology and pathogenesis. Studies have shown that ionizing radiation (IR) alters gene expression much more profoundly and a broad variety of cell-process pathways, lots of proteins are modified and activated. Our understanding of the protein in response to ionizing radiation is steadily increasing. Among the various biological processes known to induce radioresistance, PTMs have attracted marked attention in recent years. The present review summarizes the latest knowledge about how PTMs response to ionizing radiation and pathway analysis were conducted. The data provided insights into biological effects of IR and contributing to the development of novel IR-based strategies.     

Quantitative proteomic dissection of a native 14-3-3ε interacting protein complex associated with hepatocellular carcinoma

The 14-3-3 proteins regulate diverse biological processes that are implicated in cancer development, and seven 14-3-3 isoforms were identified with isoform-specific roles in different human tumors. In our previous work, we dissected the interactome of 14-3-3ε formed during the DNA damage response in a hepatocellular carcinoma (HCC) cell using an AACT/SILAC-based quantitative proteomic approach. In this study, we used a similar proteomic approach to profile/identify the 14-3-3ε interactome formed in native HCC cells. Functional categorization and data-dependent network analysis of the native HCC-specific 14-3-3ε interactome revealed that 14-3-3ε is involved in the regulation of multiple biological processes (BPs)/pathways, including cell cycle control, apoptosis, signal transduction, transport, cell adhesion, carbohydrate metabolism, and nucleic acid metabolism. Biological validation further supports that 14-3-3ε, via association with multiple BP/pathway-specific proteins, coordinates the regulation of proliferation, survival, and metastasis of HCC. The findings in this study, together with those of our previous study, provide an extensive profile of the 14-3-3ε interaction network in HCC cells, which should be valuable for understanding the pathology of HCC and HCC therapy.     

Association between COMT SNP variation and timidity in Golden and Labrador Retrievers

Timidity in dogs is a trait with high heritability. However, the relevant genetic factors and markers associated with this condition are largely unknown. The function of the catechol‐O‐methyl transferase (COMT) gene has been found to be associated with human fearful or anxious emotions, and the COMT:p.Val158Met polymorphism locus is significantly related to anxious behavior. In the present study, the correlation between timidity and four single nucleotide polymorphism (SNP) variations (C.‐1666C>G c.39A>G, c.216G>A, c.482G>A) of the COMT gene was investigated in dogs. The evaluation was based on the dog courage assessment assay and a genotype and haplotype analysis in Labrador Retrievers (LR) and Golden Retrievers (GR). The principal components analysis factor structure of the courage phenotype was invariant between LR and GR. Sex, breed and age had no statistically significant effect on the timidity of the dogs. All SNP loci detected were in Hardy–Weinberg equilibrium. The c.39A>G locus was removed in the subsequent association analysis due to the significant difference between LR and GR in genotype distributions. Intriguingly, the genotypes and haplotypes of the COMT gene were significantly and highly correlated with the timidity of LR and GR. The A alleles of the COMT:c.216G>A and c.482G>A loci appeared to play a dominant role in the timid behavior of the dogs. This result supports and broadens the warrior/worrier hypothesis and will have important implications for the understanding of the evolution of temperament in dogs. Additionally, the results provide predictive genetic markers for temperament in dogs.     

Negative regulation of AMPK signaling by high glucose via E3 ubiquitin ligase MG53

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Purification of lysozyme by affinity-based reversed micellar two-phase extraction

A dye-affinity reversed micellar system was used for lysozyme purification from a crude solution of chicken egg white. The dye-affinity reversed micelles consisted of Cibacron Blue F-3GA (CB; 0.1 mM) modified lecithin (50 g/l) in n-hexane. Starting with a crude egg white solution containing lysozyme of 0.0381 mg/mg protein, lysozyme purity was increased by 16 to 20 times, reached 0.62 to 0.76 mg/mg protein. The affinity micellar system was recycled and used three times. Addition of polyoxyethylene (20) sorbitan trioleate (Tween 85) as a cosurfactant could increase the capacity of the affinity-based reversed micelles. A lysozyme recovery yield of over 70% was obtained at a forward aqueous phase pH of 9.16 using the reversed micelles additionally containing 20 g/l of Tween 85.     

Competence Mutants II. Physical and Biological Fate of Donor Transforming Deoxyribonucleic Acid

Transformation-deficient (com(-)) mutants, which are able to bind donor transforming deoxyribonucleic acid (DNA) without yielding a significant number of transformants, were studied with regard to the fate of donor DNA. In no case was there any detectable degradation into acid-soluble radioactivity after donor DNA uptake. Physical experiments showed that some of these mutants are deficient in their ability to associate donor DNA with the recipient's chromosome (dad(-) mutants, for donor association defective), whereas others are able to form what appear to be normal donor-recipient complexes. In spite of physical evidence for integration, none of the dad(-) mutants contains biologically active recombinant DNA, suggesting that they might be deficient in the recombination process (dab(-) mutants, for donor association biologically defective). Donor biological activity is not replicated in any of the mutant strains, and in some cases there is a 10-fold reduction of donor transforming DNA within 60 min after DNA uptake.