Tyrosine phosphorylated Disabled 1 recruits Crk family adapter proteins

Disabled 1 (Dab1) functions as a critical adapter protein in the Reelin signaling pathway to direct proper positioning of neurons during brain development. Reelin stimulates phosphorylation of Dab1 on tyrosines 198 and 220, and phosphorylated Dab1 is likely to interact with downstream signaling proteins that contain Src homology 2 (SH2) domains. To search for such proteins, we used a Sepharose-conjugated peptide containing phosphotyrosine 220 (PTyr-220) of Dab1, as an affinity matrix to capture binding proteins from mouse brain extracts. Mass spectrometric analysis of bound proteins revealed that Crk family adapter proteins selectively associated with this phosphorylation site. We further show that Crk-I and Crk-II, but not CrkL, stimulate phosphorylation of Dab1 on tyrosine 220 in a Src-dependent manner. Our results suggest that Crk family adapter proteins may play an important role in the Reelin signaling pathway during brain development.     

Involvement of the N-terminal B-box Domain of Arabidopsis BBX32 Protein in Interaction with Soybean BBX62 Protein

Previous studies have demonstrated that Arabidopsis thaliana BBX32 (AtBBX32) represses light signaling in A. thaliana and that expression of AtBBX32 in soybean increases grain yield in multiple locations and multiyear field trials. The BBX32 protein is a member of the B-box zinc finger family from A. thaliana and contains a single conserved Zn(2+)-binding B-box domain at the N terminus. Although the B-box domain is predicted to be involved in protein-protein interactions, the mechanism of interaction is poorly understood. Here, we provide in vitro and in vivo evidence demonstrating the physical and functional interactions of AtBBX32 with another B-box protein, soybean BBX62 (GmBBX62). Deletion analysis and characterization of the purified B-box domain indicate that the N-terminal B-box region of AtBBX32 interacts with GmBBX62. Computational modeling and site-directed mutagenesis of the AtBBX32 B-box region identified specific residues as critical for mediating the interaction between AtBBX32 and GmBBX62. This study defines the plant B-box as a protein interaction domain and offers novel insight into its role in mediating specific protein-protein interactions between different plant B-box proteins.     

The cytotoxicity and anticancer mechanisms of alterporriol L, a marine bianthraquinone, against MCF-7 human breast cancer cells

Alterporriol L, a new bianthraquinone derivative, was isolated from a marine fungus Alternaria sp. ZJ9-6B. The cytotoxic activity and anticancer mechanisms of alterporriol L towards breast cancer cells lines were detected using MTT assay, immunofluorescence, and flow cytometry. Simultaneously, the changes in morphological properties of cells were detected before and after treatment with alterporriol L by atomic force microscope (AFM) at a nanometer scale. MTT assay showed that alterporriol L could effectively inhibit the growth and proliferation, and there was a dose-dependent manner of cell death. Moreover, the alterporriol L could induce cancer cell apoptosis or necrosis. Furthermore, the reactive oxygen species, mitochondrial membrane potential, and cytosolic free calcium level were changed after treatment with alterporriol L, suggesting that alterporriol L played vital roles in breast cancer cells through destroying the mitochondrial. And all these alterations are in accord with changes of morphology detected by AFM, which suggested that the AFM is a useful tool to detect the morphological changes of the cancer cells.     

Pimarane diterpenes from the fungus Epicoccum sp. HS-1 associated with Apostichopus japonicus

Three new pimarane diterpenes (1, 2 and 3) as well as a known compound 4, were isolated from the marine-derived fungus HS-1 from Apostichopus japonicus. Their structures and relative stereochemistry of 1-3 were elucidated using a combination of NMR spectroscopy and CD. In the primary bioassay, compounds 1, 2 and 4 inhibited the growth of KB and KBv200 with IC(50) of 3.51, 2.34 μg/mL, 20.74, 14.47 μg/mL, and 3.86, 6.52 μg/mL, respectively.     

Evolutionary history of the odd-nosed monkeys and the phylogenetic position of the newly described Myanmar snub-nosed monkey Rhinopithecus strykeri

Odd-nosed monkeys represent one of the two major groups of Asian colobines. Our knowledge about this primate group is still limited as it is highlighted by the recent discovery of a new species in Northern Myanmar. Although a common origin of the group is now widely accepted, the phylogenetic relationships among its genera and species, and the biogeographic processes leading to their current distribution are largely unknown. To address these issues, we have analyzed complete mitochondrial genomes and 12 nuclear loci, including one X chromosomal, six Y chromosomal and five autosomal loci, from all ten odd-nosed monkey species. The gene tree topologies and divergence age estimates derived from different markers were highly similar, but differed in placing various species or haplogroups within the genera Rhinopithecus and Pygathrix. Based on our data, Rhinopithecus represent the most basal lineage, and Nasalis and Simias form closely related sister taxa, suggesting a Northern origin of odd-nosed monkeys and a later invasion into Indochina and Sundaland. According to our divergence age estimates, the lineages leading to the genera Rhinopithecus, Pygathrix and Nasalis+Simias originated in the late Miocene, while differentiation events within these genera and also the split between Nasalis and Simias occurred in the Pleistocene. Observed gene tree discordances between mitochondrial and nuclear datasets, and paraphylies in the mitochondrial dataset for some species of the genera Rhinopithecus and Pygathrix suggest secondary gene flow after the taxa initially diverged. Most likely such events were triggered by dramatic changes in geology and climate within the region. Overall, our study provides the most comprehensive view on odd-nosed monkey evolution and emphasizes that data from differentially inherited markers are crucial to better understand evolutionary relationships and to trace secondary gene flow.     

Screening microbial strain for improving the nutritional value of wheat and corn straws as animal feed

From 18 strains of cellulolytic microorganisms including bacteria and filamentous fungi, one strain of soft rot fungus identified as Chaetomium cellulolyticum was screened with respect to stronger decomposition ability of cellulose and hemicellulose and its ability for protein synthesis. As it grew on raw corn straw in solid layer fermentation (SLF) for 5 days, the amino acid content in the fermentation product attained 19.29% (w/w) from 6.43% while the total cell wall was reduced by 54%. A toxicity test with mice showed that the fermentation product is not poisonous. The two filamentous fungi, Trichoderma pseudokoningii S-38 and Penicillium decumbens JU-A10 produced large amounts of extracellular cellulase and hemicellulase in the SLF process, but their growth was limited and they sporulated profusely with regard to their value as animal feed products.     

Chemistry and weak antimicrobial activities of phomopsins produced by mangrove endophytic fungus Phomopsis sp. ZSU-H76

Three metabolites named phomopsin A (1), B (2) and C (3), together with two known compounds cytosporone B (4) and C (5), were isolated from the mangrove endophytic fungus, Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly by 1D and 2D NMR spectroscopic techniques. The medium-sized cyclic phenol ether based on 1 or 2 is rare in natural products. In bioassays, compounds 1, 2, and 3 had no significant antibiotic activities, but compounds 4 and 5 inhibited two fungi Candida albicans and Fusarium oxysporum with an MIC ranging from 32 to 64 microg/ml.     

How Human Household Size Affects the Habitat of Black-and-White Snub-Nosed Monkeys (<Emphasis Type="Italic">Rhinopithecus bieti</Emphasis>) in Hongla Snow Mountain Nature Reserve in Tibet,China

Human impacts on the environment at local or regional scales largely depend on intrinsic characteristics of the population, such as household size, household number, and human population growth. These demographic factors can vary considerably among ethnic groups sharing similar ecological landscapes, yet the role of traditional cultural practices in shaping local environmental impacts is not well known for many parts of the world. We here quantify land-cover changes and their relation to the habitat of the endangered Rhinopithecus bieti in Tibet, in 2 areas populated by different ethnic groups (polyandrous Tibetans and monogamous Naxi) from 1986 to 2006. Results indicate that habitat of the monkey decreased greatly within our study area over the 20-yr period. Polyandrous and monogamous ethnic communities differed in household size, household number, population growth, and per capita and per household land use. The practice of polyandry by ethnic Tibetan appears to have reduced per capita resource consumption by reducing the growth of overall household number and increasing household size, which can mitigate the negative effects of higher human density and population growth on the environment. Ethnic Tibetan may also reduce land impacts by adhering to Buddhist customs and alternative, more sustainable means of livelihood. Accordingly, the protection of traditional cultural resources, such as polyandry and Buddhist beliefs, could be an effective way to aid biodiversity and environmental conservation efforts in this key ecosystem.     

Secalonic acid A reduced colchicine cytotoxicity through suppression of JNK, p38 MAPKs and calcium influx

There are few articles about the cytotoxicity evoked by secalonic acid A (SAA) in some tumor cells. It has not yet been reported whether SAA has any action on neurons of the central nervous system. The aim of this study was to investigate the protective effect of SAA against apoptosis of rat cortical neurons induced by colchicine. The protective action of SAA on the cortical neurons treated with colchicine at 1 μM was examined by Hoechst 33258, LDH release and flow cytometry methods. The results from the above tests indicated that SAA at 3 and 10 μM significantly prevented colchicine-induced apoptosis of the cortical neurons. Further studies from Western blot and confocal microscopy experiments showed that the activation of JNK, p38 MAPKs and caspase-3 during neuron apoptosis triggered by 1 μM colchicine could be obviously suppressed by SAA; on the other hand, an increase in the intracellular free Ca(2+) by 1 μM colchicine in the cortical neuron was blocked evidently by SAA. The above results suggested that SAA could antagonize the cytotoxicity of colchicine in the rat cortical neurons, which may be through inhibition of phosphorylation of JNK and p38 MAPKs, calcium influx, and the activation of caspase-3.