Precise contact between epithelial cells and their underlying basement membrane is crucial to the maintenance of tissue architecture and function. To understand the role that the laminin receptor dystroglycan (DG) plays in these processes, we assayed cell responses to laminin-111 following conditional ablation of DG gene (Dag1) expression in cultured mammary epithelial cells. Strikingly, DG loss disrupted laminin-111-induced polarity and β-casein production, and abolished laminin assembly at the step of laminin binding to the cell surface. Dystroglycan re-expression restored these deficiencies. Investigations of the mechanism revealed that DG cytoplasmic sequences were not necessary for laminin assembly and signaling, and only when the entire mucin domain of extracellular DG was deleted did laminin assembly not occur. These results demonstrate that DG is essential as a laminin-111 co-receptor in mammary epithelial cells that functions by mediating laminin anchoring to the cell surface, a process that allows laminin polymerization, tissue polarity and β-casein induction. The observed loss of laminin-111 assembly and signaling in Dag1-/- mammary epithelial cells provides insights into the signaling changes occurring in breast carcinomas and other cancers, where the binding function of DG to laminin is frequently defective.

Graphitic carbon nitride (g-CN) has attracted enormous interest in applications as a visible-light-driven photocatalyst, particularly for hydrogen evolution via water splitting. Despite intensive photocatalytic works to achieve higher hydrogen-evolution rate, the chemical and electronic structures that are essential for the water photolysis reactions have not been comprehensibly understood. To reveal the fundamental properties, we utilized well-oriented g-CN films for reliable analyses with several types of electron spectroscopies. Comparing X-ray photoelectron spectra of the g-CN film with those of a g-CN monomer, melem, provided a definite peak assignment of the spectra, from which we identified g-CN as melon. The analysis with ultraviolet photoelectron and inverse photoemission spectroscopy (UPS and IPES) for the melon film clarified energy distributions of the occupied and unoccupied electronic states near the energy gap of melon, respectively. Band structure calculations of a melon crystal revealed orbital characteristics of the electronic states. The calculations also implied that the energy dispersion of only the lowest unoccupied molecular orbital is present along melon chains. The energy structure of melon, determined by the UPS and IPES spectra, was demonstrated to be preferable for water splitting. The results shown in this study will facilitate designs of superior polymeric photocatalysts.

Glutathione protects cells and organisms from oxygen species and peroxides and is indispensable for aerobically living organisms. Moreover, it acts against xenobiotics and drugs by the formation and excretion of glutathione S conjugates. In this study, we show that the yliA, -B, -C, and -D genes of Escherichia coli K-12 encode a glutathione transporter with the ATP-binding cassette. The transporter imports extracellular glutathione into the cytoplasm in an ATP-dependent manner. This transporter, along with ␥-glutamyltranspeptidase, has an important role in E. coli growth with glutathione as a sole sulfur source.

Beer foam polypeptides have been separated into five groups based on their relative hydrophobicity. Foam stability increases with increasing hydrophobicity of the polypeptide groups. The most hydrophobic polypeptide group contains a large proportion of Coomassie blue-binding polypeptides. Analysis by SDS-PAGE reveals that each polypeptide group is composed of several differently-sized polypeptides. Further purification by anion-exchange chromatography results in five fractions, each of which has a different polypeptide profile on SDS-polyacrylamide gels.

Eight monoclonal antibodies (mAb) recognising barley polypeptides have been identified from a library developed to wheat prolamins. The specificity of the rnAb has been determined using enzyme-linked immunosorbent assay (ELISA) and irnmunoblotting. Six were of broad specificity, recognising D, B, C and y-hordeins to varying degrees by both techniques. IFRN 0610 preferentially recognised y-hordeins by ELISA but was highly specific for this hordein group by immunoblotting. Another mAb, IFRN 0624, bound to a M , z 18000 polypeptide belonging to the CM protein (trypsin/a-amylase inhibitor) family by immunoblotting. This, or a related protein, was detected by 0624 in all hordein fractions using ELISA. These mAb, together with two others described previously and found to recognise the repeat motif of C hordein, were used in ELISA and immunoblot analysis of Octyl-Sepharose fractions of lager foam. Hordein polypeptides were found in all foam fractions, indicating that much foam protein originates from the malt. The CM-like protein was found present in a virtually unmodified form. In contrast, the repeat motif of C hordein was not detected, indicating that it had either been destroyed or masked by other beer constituents. The foam stabilising agent, propylene glycol alginate (PGA), increased the apparent hydrophobicity of hordein fragments suggesting that at least part of the activity of PGA is mediated by interactions with the hordein components of foam.