Effect of Proteolytic Modification on Texture and Mastication of Heat-Treated Egg White Gels.

Unlabelled: Raw egg white undergoes sol-gel transition by heat treatment, which changes it to an elastic gel. Here, protease treatment to render a new texture to heated egg white gel was applied. Protease-treated gels exhibited ductile flow without obvious rupture points.

Construction of a crown ether-like supramolecular library by conjugation of genetically-encoded peptide linkers displayed on bacteriophage T7.

By using the 10BASEd-T, we have synthesized a crown ether-like macrocyclic library possessing randomized peptide linkers on bacteriophage T7. Among 1.5 × 10(9) diversities of the supramolecule candidates, we have obtained a specific binder for the N-terminal domain of Hsp90.

Hsp90 is involved in the formation of P-bodies and stress granules.

Previously, we found that treatment of cells with the Hsp90 inhibitor geldanamycin (GA) leads to a substantial reduction in the number of processing bodies (P-bodies), and also alters the size and subcellular localization of stress granules. These findings imply that the chaperone activity of Hsp90 is involved in the formation of P-bodies and stress granules. To verify these observations, we examined whether another Hsp90 inhibitor radicicol (RA) affected P-bodies and stress granules.

The Hsp90 inhibitor geldanamycin abrogates colocalization of eIF4E and eIF4E-transporter into stress granules and association of eIF4E with eIF4G.

The eukaryotic translation initiation factor eIF4E plays a critical role in the control of translation initiation through binding to the mRNA 5' cap structure. eIF4E is also a component of processing bodies and stress granules, which are two types of cytoplasmic RNA granule in which translationally inactivated mRNAs accumulate. We found that treatment with the Hsp90 inhibitor geldanamycin leads to a substantial reduction in the number of HeLa cells that contain processing bodies.

Application of an Aspergillus saitoi protease preparation to soybean curd to modify its functional and rheological properties.

An Aspergillus saitoi protease preparation, Molsin, was found to contain beta-glucosidase as well as protease activities. Application of Molsin to soybean curd improved its functionality by converting the contained isoflavone glycosides to their aglycones through beta-glucosidase, and also modified the rheological property into a creamy consistency through protease. The enzymatically modified soybean curd was characterized by a ductility flow having no particular rupture point.

Up-regulation of genes related to the ubiquitin-proteasome system in the brown adipose tissue of 24-h-fasted rats.

The functional balance between brown adipose tissue (BAT) and white adipose tissue (WAT) is important for metabolic homeostasis. We compared the effects of fasting on the gene expression profiles in BAT, WAT and liver by using a DNA microarray analysis. Tissues were obtained from rats that had been fed or fasted for 24 h.

Client binding of Cdc37 is regulated intramolecularly and intermolecularly.

Recently we showed that the glycine-rich loop in the N-terminal portion of protein kinases and the client-binding site of Cdc37 are both necessary for interaction between Cdc37 and protein kinases. We demonstrate here that the N-terminal portion of Cdc37, distinct from its client-binding site, interacts with the C-terminal portion of Raf-1. This interaction might expose the client-binding site of Cdc37.

The proteasome activator PA28 functions in collaboration with Hsp90 in vivo.

We have previously shown that the proteasome activator PA28 is essential to Hsp90-dependent protein refolding in vitro, where PA28 mediates transfer of the Hsp90-bound substrate protein to the Hsc70/Hsp40 chaperone machine for its correct refolding. This observation suggests that PA28 may also collaborate with Hsp90 in cells. To examine this possibility, here we have used double-stranded RNA interference (RNAi) against PA28 in Caenorhabditis elegans mutants of daf-21, which encodes Hsp90.

Depletion of hsp90beta induces multiple defects in B cell receptor signaling.

Hsp90 participates in many distinct aspects of cellular functions and accomplishes these roles by interacting with multiple client proteins. To gain insight into the interactions between Hsp90 and its clients, here we have reduced the protein level of Hsp90 in avian cells by gene targeting in an attempt to elicit the otherwise undetectable (because of the vast amount of cellular Hsp90) Hsp90-interacting proteins. Hsp90beta-deficient cells can grow, albeit more slowly than wild-type cells.

Purification and assay of the chaperone-dependent ubiquitin ligase of the carboxyl terminus of Hsc70-interacting protein.

It is notable that both chaperone and ubiquitin-proteasome systems are required for the removal of aberrant cellular proteins to ensure protein homeostasis in cells. However, the entity that links the two systems had remained elusive. The carboxyl terminus of Hsc70-interacting protein (CHIP), originally identified as a cochaperone of Hsc70, has both a TPR motif and a U-box domain.

Constantly updated knowledge of Hsp90.

Although protein folding, in principle is a spontaneous process which depends only upon the amino-acid sequence, the assistance of molecular chaperones is required for many proteins to achieve their final conformation in vivo. While Hsp90 is one of the major molecular chaperones, it has long been the most mysterious among them. Recent advances in our knowledge regarding Hsp90 structure and function, owing to both detailed biochemical and genetic characterizations of Hsp90 co-chaperones, as well as eminent structural studies have established Hsp90 as an ATPase-dependent chaperone, and have provided a paradigm of the Hsp90 chaperone cycle, which is sequentially tuned and coordinated by a variety of co-chaperones.