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.     

Non‐pollinating cheater wasps benefit from seasonally poor performance of the mutualistic pollinating wasps at the northern limit of the range of Ficus microcarpa

1. Species interactions in tightly bound ecological mutualisms often feature highly specialised species' roles in which competitive exclusion may preclude multi‐species coexistence. Among the 800 fig (Ficus) species, it was originally considered that each was pollinated by their own wasp (Agaonidae). However, recent investigations show that this ‘one‐to‐one’ rule often breaks down, as fig species regularly host multiple agaonids but in ways suggesting that competitive processes still mediate biodiversity outcomes. 2. A phenological survey was conducted of the fig–fig wasp pair, Ficus microcarpa and its associated pollinating wasp, alongside its sister species, the cheating wasp, in Xishuangbanna, China. 3. Reproductive output underwent extreme seasonal variation. Seed and pollinator production fell markedly during cooler, drier months, although high levels of fig production continued. However, this resource was predominantly utilised by the cheater species, which offers no pollination services. Pollinators and cheaters rarely co‐occur, suggesting that temporal coexistence is constrained by competition for access to figs. 4. The overall findings indicate periodic rearrangements of mutualism dynamics, probably resulting from a strongly seasonal environment. Sympatric co‐occurrence may result from a window of opportunity for a functionally divergent agaonid, potentially due to constraints on the main pollinator in adapting to variable year‐round conditions that prevent competitive exclusion.     

Highly specialized Cretaceous beetle parasitoids (Ripiphoridae) identified with optimized visualization of microstructures

Extremely miniaturized longipedes insects (body length c. 0.3 mm) embedded in two pieces of Cretaceous amber from Myanmar are described and interpreted. Using inverted fluorescence and light microscopy for detailed analysis of microstructures, the inclusions were identified as primary larvae of the beetle family Ripiphoridae, subfamily Ripidiinae. While the structure of thoracic and abdominal segments including appendages corresponds well with the groundplan known in recent members of Ripidiinae, a curved prosternal ridge with prominent spines (each c. 5 μm), the reduced condition of stemmata and antennae and the lack of sharp mandibles are unique features within the entire family, apparently apomorphies of the longipedes larvae. A sinuate prosternal edge with a dense row of spines (prosternoctenidium) might be homologous with ‘head ctenidia’ in some previously described miniaturized conicocephalate larvae, but further investigation is needed. The morphological differences between the head of longipedes larvae and extant Ripidiinae are interpreted as adaptations to different groups of hosts and life strategies. Palaeoethology of the longipedes larvae is briefly discussed. In addition, the systematic placement of conicocephalate larvae from Canadian, Myanmar and Russian Cretaceous ambers, already interpreted by various authors as primary instars within Coleopterida (assigned to either Strepsiptera or to the coleopteran Tenebrionoidea: Ripiphoridae), is discussed.     

Expression of the catalytic subunit of phosphorylase phosphatase (protein phosphatase-1) in Escherichia coli.

The catalytic subunit of rabbit skeletal muscle protein phosphatase-1 was expressed in Escherichia coli. Expression of phosphatase-1 in the pET3a vector, which is based on the use of the T7 promoter, resulted in the expression of the enzyme as an insoluble aggregate. The insoluble enzyme could be renatured by high dilutions of the urea-solubilized protein in buffers containing dithiothreitol, Mn2+, and high NaCl concentrations. However, under all conditions tested, only partial (less than 5%) renaturation was achieved. A second attempt was made using a vector with the trp-lac hybrid promoter. In this case it was possible to express the enzyme as a soluble protein at levels of 3-4% of the soluble E. coli protein. The recombinant enzyme was purified by DEAE-Sepharose and heparin-Sepharose chromatography. Approximately 20 mg of purified enzyme was reproducibly obtained from the cells derived from 2 liters of culture. The purified enzyme had a specific activity toward phosphorylase alpha comparable to that reported for the authentic protein and had an Mr of 37,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The recombinant enzyme displayed similar sensitivities to inhibition by inhibitor-2, okadaic acid, and microcystin-LR as for the protein isolated from rabbit muscle. At all stages of purification the recombinant phosphatase behaved as an essentially inactive enzyme that required the presence of microM Mn2+ for full expression of its activity.