Characteristics of a mesoporous silicate immobilized trypsin bioreactor in organic media

Mesoporous silicates (MPS) materials are attractive materials for immobilizing proteins/enzymes because of their well ordered structures, large surface areas (up to 1000 m(2) g(-1)), narrow pore size distributions, large pore diameters, and pore volumes. MPS with average pore diameters ranging from 28 to 300 Angstroms were prepared using cationic and nonionic surfactants. The influence of water content, pH, storage, and thermal treatment on the activity of trypsin immobilized onto MPS was investigated. In a range of solvents, the amidolytic activity of immobilized trypsin was higher than that of the lyophilized preparation. Significant increases in k(cat)/K(M) occurred in propanol, ethanol, methanol, and formamide of 90, 62, 45 and 26, respectively. The observed increases were primarily a result of substantial increases in k(cat).     

Simultaneous binding of Guidance Cues NET1 and RGM blocks extracellular NEO1 signaling

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Interactions of the EphA2 Kinase Domain with PIPs in Membranes: Implications for Receptor Function

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Genomic and physiological analyses of an indigenous strain, <Emphasis Type="Italic">Enterococcus faecium</Emphasis> 17OM39

The human gut microbiome plays a crucial role in human health and efforts need to be done for cultivation and characterisation of bacteria with potential health benefits. Here, we isolated a bacterium from a healthy Indian adult faeces and investigated its potential as probiotic. The cultured bacterial strain 17OM39 was identified as Enterococcus faecium by 16S rRNA gene sequencing. The strain 17OM39 exhibited tolerance to acidic pH, showed antimicrobial activity and displayed strong cell surface traits such as hydrophobicity and autoaggregation capacity. The strain was able to tolerate bile salts and showed bile salt hydrolytic (BSH) activity, exopolysaccharide production and adherence to human HT-29 cell line. Importantly, partial haemolytic activity was detected and the strain was susceptible to the human serum. Genomics investigation of strain 17OM39 revealed the presence of diverse genes encoding for proteolytic enzymes, stress response systems and the ability to produce essential amino acids, vitamins and antimicrobial compound Bacteriocin-A. No virulence factors and plasmids were found in this genome of the strain 17OM39. Collectively, these physiological and genomic features of 17OM39 confirm the potential of this strain as a candidate probiotic.     

Significance of PELP1 in ER-negative breast cancer metastasis

Breast cancer metastasis is a major clinical problem. The molecular basis of breast cancer progression to metastasis remains poorly understood. PELP1 is an estrogen receptor (ER) coregulator that has been implicated as a proto-oncogene whose expression is deregulated in metastatic breast tumors and whose expression is retained in ER-negative tumors. We examined the mechanism and significance of PELP1-mediated signaling in ER-negative breast cancer progression using two ER-negative model cells (MDA-MB-231 and 4T1 cells) that stably express PELP1-shRNA. These model cells had reduced PELP1 expression (75% of endogenous levels) and exhibited less propensity to proliferate in growth assays in vitro. PELP1 downregulation substantially affected migration of ER-negative cells in Boyden chamber and invasion assays. Using mechanistic studies, we found that PELP1 modulated expression of several genes involved in the epithelial mesenchymal transition (EMT), including MMPs, SNAIL, TWIST, and ZEB. In addition, PELP1 knockdown reduced the in vivo metastatic potential of ER-negative breast cancer cells and significantly reduced lung metastatic nodules in a xenograft assay. These results implicate PELP1 as having a role in ER-negative breast cancer metastasis, reveal novel mechanism of coregulator regulation of metastasis via promoting cell motility/EMT by modulating expression of genes, and suggest PELP1 may be a potential therapeutic target for metastatic ER-negative breast cancer.     

Mammalian microtubule P-body dynamics are mediated by nesprin-1

Nesprins are a multi-isomeric family of spectrin-repeat (SR) proteins, predominantly known as nuclear envelope scaffolds. However, isoforms that function beyond the nuclear envelope remain poorly examined. Here, we characterize p50^Nesp1, a 50-kD isoform that localizes to processing bodies (PBs), where it acts as a microtubule-associated protein capable of linking mRNP complexes to microtubules. Overexpression of dominant-negative p50^Nesp1 caused Rck/p54, but not GW182, displacement from microtubules, resulting in reduced PB movement and cross talk with stress granules (SGs). These cells disassembled canonical SGs induced by sodium arsenite, but not those induced by hydrogen peroxide, leading to cell death and revealing PB–microtubule attachment is required for hydrogen peroxide-induced SG anti-apoptotic functions. Furthermore, p50^Nesp1 was required for miRNA-mediated silencing and interacted with core miRISC silencers Ago2 and Rck/p54 in an RNA-dependent manner and with GW182 in a microtubule-dependent manner. These data identify p50^Nesp1 as a multi-functional PB component and microtubule scaffold necessary for RNA granule dynamics and provides evidence for PB and SG micro-heterogeneity.