Mtc6/Ehg2 is a novel endoplasmic reticulum-resident glycoprotein essential for high-pressure tolerance.

Hydrostatic pressure is a common mechanical stressor that modulates metabolism and reduces cell viability. Eukaryotic cells have genetic programs to cope with hydrostatic pressure stress and maintain intracellular homeostasis. However, the mechanism underlying hydrostatic pressure tolerance remains largely unknown.

Yeast Rim11 kinase responds to glutathione-induced stress by regulating the transcription of phospholipid biosynthetic genes.

Glutathione (GSH), a tripeptide composed of glycine, cysteine, and glutamic acid, is an abundant thiol found in a wide variety of cells, ranging from bacterial to mammalian cells. Adequate levels of GSH are essential for maintaining iron homeostasis. The ratio of oxidized/reduced GSH is strictly regulated in each organelle to maintain the cellular redox potential.

Jerveratrum-Type Steroidal Alkaloids Inhibit β-1,6-Glucan Biosynthesis in Fungal Cell Walls.

The limited number of available effective agents necessitates the development of new antifungals. We report that jervine, a jerveratrum-type steroidal alkaloid isolated from Veratrum californicum, has antifungal activity. Phenotypic comparisons of cell wall mutants, K1 killer toxin susceptibility testing, and quantification of cell wall components revealed that β-1,6-glucan biosynthesis was significantly inhibited by jervine.

A novel ER membrane protein Ehg1/May24 plays a critical role in maintaining multiple nutrient permeases in yeast under high-pressure perturbation.

Previously, we isolated 84 deletion mutants in Saccharomyces cerevisiae auxotrophic background that exhibited hypersensitive growth under high hydrostatic pressure and/or low temperature. Here, we observed that 24 deletion mutants were rescued by the introduction of four plasmids (LEU2, HIS3, LYS2, and URA3) together to grow at 25 MPa, thereby suggesting close links between the genes and nutrient uptake. Most of the highly ranked genes were poorly characterized, including MAY24/YPR153W.

Free glycans derived from -mannosylated glycoproteins suggest the presence of an -glycoprotein degradation pathway in yeast.

In eukaryotic cells, unconjugated oligosaccharides that are structurally related to -glycans ( free -glycans) are generated either from misfolded -glycoproteins destined for the endoplasmic reticulum-associated degradation or from lipid-linked oligosaccharides, donor substrates for -glycosylation of proteins. The mechanism responsible for the generation of free -glycans is now well-understood, but the issue of whether other types of free glycans are present remains unclear. Here, we report on the accumulation of free, -mannosylated glycans in budding yeast that were cultured in medium containing mannose as the carbon source.

Both Svp26 and Mnn6 are required for the efficient ER exit of Mnn4 in Saccharomyces cerevisiae.

Incorporation of membrane and secretory proteins into COPII vesicles are facilitated either by the direct interaction of cargo proteins with COPII coat proteins, or by ER exit adaptor proteins which mediate the interaction of cargo proteins with COPII coat proteins. Svp26 is one of the ER exit adaptor proteins in the yeast Saccharomyces cerevisiae. The ER exit of several type II membrane proteins have been reported to be facilitated by Svp26.

Svp26 facilitates ER exit of mannosyltransferases Mnt2 and Mnt3 in Saccharomyces cerevisiae.

After being translocated into the ER lumen, membrane and secretory proteins are transported from the ER to the early Golgi by COPII vesicles. Incorporation of these cargo proteins into COPII vesicles are facilitated either by direct interaction of cargo proteins with COPII coat proteins or by ER exit adaptor proteins which mediate the interaction of cargo proteins with COPII coat proteins. Svp26 is one of the ER exit adaptor proteins in yeast Saccharomyces cerevisiae.

Distinct adaptor proteins assist exit of Kre2-family proteins from the yeast ER.

The Svp26 protein of S. cerevisiae is an ER- and Golgi-localized integral membrane protein with 4 potential membrane-spanning domains. It functions as an adaptor protein that facilitates the ER exit of Ktr3, a mannosyltransferase required for biosynthesis of O-linked oligosaccharides, and the ER exit of Mnn2 and Mnn5, mannosyltransferases, which participate in the biosynthesis of N-linked oligosaccharides.

Molecular mechanisms of the localization of membrane proteins in the yeast Golgi compartments.

The Golgi apparatus of the eukaryotic cell is an essential organelle at the center of the network of vesicular transport delivering proteins and lipids to the correct locations in the cell. There are several Golgi compartments that have distinct resident proteins and functions, but the mechanism creating and maintaining the differences has long been an unsolved mystery in cell biology. After the discovery and molecular characterization of the transport vesicles and their coat proteins, we realized that the Golgi is an extremely dynamic organelle existing as repeating cycles of appearance, maturation, and disappearance.

Action of multiple endoplasmic reticulum chaperon-like proteins is required for proper folding and polarized localization of Kre6 protein essential in yeast cell wall β-1,6-glucan synthesis.

Saccharomyces cerevisiae Kre6 is a type II membrane protein essential for cell wall β-1,6-glucan synthesis. Recently we reported that the majority of Kre6 is in the endoplasmic reticulum (ER), but a significant portion of Kre6 is found in the plasma membrane of buds, and this polarized appearance of Kre6 is required for β-1,6-glucan synthesis. An essential membrane protein, Keg1, and ER chaperon Rot1 bind to Kre6.

Neoadjuvant intraarterial chemotherapy for stage IIB-IIIB cervical cancer in Japanese women.

Chemoradiotherapy is currently the main treatment for locally advanced cervical cancer, but neoadjuvant intraarterial chemotherapy (IA-NAC) has been reported to achieve favorable results. This study investigated the efficacy of several different IA-NAC regimens. The subjects were 55 patients with stage IIB-IIIB cervical cancer who received IA-NAC between January 1991 and April 2006.

Inhibitory activity of blasticidin A, a strong aflatoxin production inhibitor, on protein synthesis of yeast: selective inhibition of aflatoxin production by protein synthesis inhibitors.

Blasticidin A (BcA), an antibiotic produced by Streptomyces, inhibits aflatoxin production without strong growth inhibition toward aflatoxin-producing fungi. During the course of our study on the mode of action of BcA by two-dimensional differential gel electrophoresis (2D-DIGE), we found a decrease in the abundances of ribosomal proteins in Saccharomyces cerevisiae after exposure to BcA. This phenomenon was also observed by treatment with blasticidin S (BcS) or cycloheximide.

Svp26 facilitates endoplasmic reticulum to golgi transport of a set of mannosyltransferases in Saccharomyces cerevisiae.

Svp26 is a polytopic integral membrane protein found in the ER and early Golgi compartment. In the Deltasvp26 cell, the Golgi mannosyltransferase Ktr3 remains in the ER. Here, we report that two other Golgi mannosyltransferases, Mnn2 and Mnn5 are also mislocalized and found in the ER in the absence of Svp26 and that localization of other mannosyltransferases including Mnn1 are not affected.

Kei1: a novel subunit of inositolphosphorylceramide synthase, essential for its enzyme activity and Golgi localization.

Fungal sphingolipids have inositol-phosphate head groups, which are essential for the viability of cells. These head groups are added by inositol phosphorylceramide (IPC) synthase, and AUR1 has been thought to encode this enzyme. Here, we show that an essential protein encoded by KEI1 is a novel subunit of IPC synthase of Saccharomyces cerevisiae.

BMP4 induces primitive endoderm but not trophectoderm in monkey embryonic stem cells.

Monkey embryonic stem (ES) cells share similar characteristics to human ES cells and provide a primate model of allotransplantation, which allows to validate efficacy and safety of cell transplantation therapy in regenerative medicine. Bone morphogenetic protein 4 (BMP4) is known to promote trophoblast differentiation in human ES cells in contrast to mouse ES cells where BMP4 synergistically maintains self-renewal with leukemia inhibitory factor (LIF), which represents a significant difference in signal transduction of self-renewal and differentiation between murine and human ES cells. As the similarity of the differentiation mechanism between monkey and human ES cells is of critical importance for their use as a primate model system, we investigated whether BMP4 induces trophoblast differentiation in monkey ES cells.

Ypt11 functions in bud-directed transport of the Golgi by linking Myo2 to the coatomer subunit Ret2.

A yeast class V myosin Myo2 transports the Golgi into the bud during its inheritance. However, the mechanism that links the Golgi to Myo2 is unknown. Here, we report that Ypt11, a Rab GTPase that reportedly interacts with Myo2, binds to Ret2, a subunit of the coatomer complex.

Side population cells contribute to the genesis of human endometrium.

Objective: To investigate whether stem (progenitor) cells are found in human endometrial side population cells.

Design: Experimental laboratory study.

Setting: University-based laboratory in Japan.

Analysis of splenic Gr-1int immature myeloid cells in tumor-bearing mice.

It is known that the number of ImC, expressing myeloid markers, CD11b and Gr-1, increase with tumor growth and ImC play a role in the escape of tumor cells from immunosurveillance in tumor-bearing mice and cancer patients. However, the mechanisms by which ImC suppress immune responses in tumor-bearing mice have not been completely elucidated. In the present study, we investigated the function of splenic ImC freshly isolated from tumor-bearing mice and splenic ImC differentiated in vitro by GM-CSF.

KEG1/YFR042w encodes a novel Kre6-binding endoplasmic reticulum membrane protein responsible for beta-1,6-glucan synthesis in Saccharomyces cerevisiae.

KEG1/YFR042w of Saccharomyces cerevisiae is an essential gene that encodes a 200-amino acid polypeptide with four predicted transmembrane domains. The green fluorescent protein- or Myc(6)-tagged Keg1 protein showed the typical characteristics of an integral membrane protein and was found in the endoplasmic reticulum by fluorescence imaging. Immunoprecipitation from the Triton X-100-solubilized cell lysate revealed that Keg1 binds to Kre6, which has been known to participate in beta-1,6-glucan synthesis.

Pga1 is an essential component of Glycosylphosphatidylinositol-mannosyltransferase II of Saccharomyces cerevisiae.

The Saccharomyces cerevisiae essential gene YNL158w/PGA1 encodes an endoplasmic reticulum (ER)-localized membrane protein. We constructed temperature-sensitive alleles of PGA1 by error-prone polymerase chain reaction mutagenesis to explore its biological role. Pulse-chase experiments revealed that the pga1(ts) mutants accumulated the ER-form precursor of Gas1 protein at the restrictive temperature.

Concomitant treatment of severe uterine adenomyosis in a premenopausal woman with an aromatase inhibitor and a gonadotropin-releasing hormone agonist.

Objective: To assess the effect of aromatase inhibitors with GnRH agonist for a severe symptomatic adenomyosis that is refractory to GnRH agonist and danazol with GnRH agonist.

Design: Case report.

Setting: Clinical practice in university hospital.

Peculiar protein-protein interactions of the novel endoplasmic reticulum membrane protein Rcr1 and ubiquitin ligase Rsp5.

Overproduction of the ER membrane protein Rcr1 makes Saccharomyces cerevisiae resistant to Congo red by reducing the chitin content through a unknown mechanism. By both co-immunoprecipitation and yeast two-hybrid experiments, specific interaction between Rcr1 and the ubiquitin ligase Rsp5 was found. This binding was largely mediated by a singular VPEY sequence in Rcr1 in addition to PPSY, the consensus ligand motif of the WW domains.

Specific membrane recruitment of Uso1 protein, the essential endoplasmic reticulum-to-Golgi tethering factor in yeast vesicular transport.

Uso1 is a yeast essential protein that functions to tether vesicles in the ER-to-Golgi transport. Its recruitment to the ER-derived vesicles has been demonstrated in in vitro membrane transport systems using semi-intact cells. Here we report that the binding of Uso1 to specific membranes can be detected through simple sucrose density block centrifugation.

Tvp38, Tvp23, Tvp18 and Tvp15: novel membrane proteins in the Tlg2-containing Golgi/endosome compartments of Saccharomyces cerevisiae.

Four previously uncharacterized proteins (Tvp38, Tvp23, Tvp18 and Tvp15) were found in Tlg2-containing membrane by proteomic analysis of immunoisolated Golgi subcompartments of Saccharomyces cerevisiae (Inadome et al., Mol. Cell.