Comparative genomic analysis of the clade B serpin cluster at human chromosome 18q21: amplification within the mouse squamous cell carcinoma antigen gene locus

The human clade B serpins neutralize serine or cysteine proteinases and reside predominantly within the intracellular compartment. Genomic analysis shows that the 13 human clade B serpins map to either 6p25 (n = 3) or 18q21 (n = 10). Similarly, the mouse clade B serpins map to syntenic loci at 13A3.2 and 1D, respectively. The mouse clade B cluster at 13A3.2 shows a marked expansion in the number of serpin genes (n = 15). The purpose of this study was to determine whether a similar expansion occurred at 1D. Using STS-content mapping, comparative genomic DNA sequence analysis, and cDNA cloning, we found that the mouse clade B cluster at 1D showed nearly complete conservation of gene number, order, and orientation relative to those of 18q21. The only exception was the squamous cell carcinoma antigen (SCCA) locus. The human SCCA locus contains two genes, SERPINB3 (SCCA1) and SERPINB4 (SCCA2), whereas the mouse locus contains four serpins and three pseudogenes. Based on phylogenetic analysis and predicted amino acid sequences, amplification of the mouse SCCA locus occurred after rodents and primates diverged and was associated with some diversification of proteinase inhibitory activity relative to that of humans.     

Establishment and characterization of human uterine cervical epidermoid carcinoma cell line HHUS containing HPV 59 DNA

The cell line designated HHUS was established from human uterine cervical keratinizing squamous cell carcinoma. The HHUS cell line was subcultivated more than 70 times within 3 years. The cultured cells, polygonal or spindle, with neoplastic and pleomorphic features, appeared epithelial in shape, with a pavement-like arrangement and grew in multi-layers without contact inhibition. The chromosome number was varied from 40 to 88, and the modal number was stable in diploid range. The cultured cells produced keratinizing squamous cell carcinomas by heterotransplantation into the subcutis of nude mice. The HHUS cells were characterized as producing large amounts of SCC, in vitro and possessing HPV-59 DNA genomes.     

Suppressive effect of a hot water extract of adzuki beans (Vigna angularis) on hyperglycemia after sucrose loading in mice and diabetic rats

A hot water extract obtained by boiling adzuki beans (Vigna angularis) to produce bean paste for Japanese cake showed inhibitory activity against alpha-glucosidase, alpha-amylase, maltase, sucrase, and isomaltase after HP-20 column chromatography. The IC(50) values for each hydrolylase were 0.78 mg/ml (alpha-amylase), 2.45 mg/ml (maltase), 5.37 mg/ml (sucrase), and 1.75 mg/ml (isomaltase). The active fraction showed potential hypoglycemic activity in both normal mice and streptozotocin (STZ)-induced diabetic rats after an oral administration of sucrose, but did not show any effect on the blood glucose concentration after glucose administration, suggesting that the active fraction suppressed the postprandial blood glucose level by inhibiting alpha-glucosidase and alpha-amylase, irrespective of the endogenous blood insulin level.     

Changes of protein profiles during pollen development in<Emphasis Type="Italic"> Lilium longiflorum</Emphasis>

Pollen proteins of Lilium longiflorum were examined at different developmental stages (young, mature and cultured) using two-dimensional differential gel electrophoresis. Quantitative changes of six proteins (MP1–MP6) during pollen development were observed in the acidic and low molecular weight region. After water absorption on the culture medium, the quantities of all six proteins were drastically changed. Mass spectrometric analysis revealed that MP2, MP3, MP4 and MP6 are late embryogenesis abundant (LEA) (D-7) protein, profilin 3, profilin 1 and enolase, respectively. The remaining two proteins (MP1 and MP5) could not be identified by mass spectrometric analysis. Immunogold electron microscopic examination showed the presence of these proteins in different regions: MP1 around lipid bodies, suggesting possible involvement in lipid metabolism, MP4 near actin in the cytoplasm, indicating the possibility of its interaction with actin in the regulatory pathways of pollen, and MP2 and MP6 in the cytoplasm.     

Reduced sensitivity of Niemann-Pick C1-deficient cells to θ-toxin (perfringolysin O): sequestration of toxin to raft-enriched membrane vesicles

-Toxin (perfringolysin O) binds to cell surface cholesterol and forms oligomeric pores that cause membrane damage. Both in cytotoxicity and cell survival assays, a mutant Chinese hamster ovary cell line NPC1(–) that lacked Niemann-Pick C1 showed reduced sensitivity to -toxin, compared with wild-type (wt) cells. BC is a derivative of -toxin that retains cholesterol-binding activity but lacks cytotoxicity. Confocal and electron microscopy revealed the presence of multiple vesicles which bound BC, both on the cell surface and in the extracellular space of these cells. BC binding to raft microdomains was verified by its resistance to 1% Triton X-100 at 4°C and recovery of bound BC in floating low-density fractions on sucrose density gradient fractionation. BC-labeled vesicles were abolished when NPC1(–) cells were depleted of lipoproteins and also when treated with a Rho-associated kinase inhibitor Y-27632. In addition, similar vesicles were observed in wt cells treated with progesterone. In parallel with these results, -toxin sensitivity of NPC1(–) cells was increased when cells were depleted of lipoproteins or treated with Y-27632, whereas that of wt cells was decreased by progesterone. Our findings suggest that sequestration of toxin to raft-enriched cell surface vesicles may underlie reduced sensitivity of NPC1-deficient cells to -toxin.     

Modulation of the K+ efflux activity of Bacillus subtilis YhaU by YhaT and the C-terminal region of YhaS

The cation/proton antiporter 2 (CPA2) family is a large family of cation transporters and putative channel proteins that are found in bacteria, archaea as well as eukaryotes. Consistent with a K+ efflux capacity that is found in several other CPA2 proteins, it is shown here that the YhaU protein of Bacillus subtilis greatly increased the concentration of K+ required for growth of a K+ uptake-defective mutant of Escherichia coli. No YhaU-dependent K+(Na+)/H+ antiport activity was found in membrane vesicles. Two genes, yhaS and yhaT, are located upstream of yhaU and form an apparent operon with it. The YhaS protein has no reported homologues while the YhaT protein has sequence similarity to a sub-domain of KTN proteins that are associated with potassium-translocating channels and transporters. YhaT and the C-terminal region of YhaS were shown to modulate the K+ transport capacities of YhaU in complementation experiments. Expression studies, conducted by monitoring the beta-galactosidase levels in pMutin-disrupted mutants of the yhaU locus, indicated that yhaU is strongly induced by alkaline pH- plus salt-induced stress and that there are additional sodium-specific responses of yhaS and yhaT.     

Isolation of desmosomes from the epidermis of Xenopus laevis and immunochemical characterization of the Xenopus desmosomal cadherins

Here we report a new method of isolating epidermal desmosomes from Xenopus laevis, and a major constituent of desmosomes designated as Xenopus desmogleins (XDsg). Isolation of desmosomes from Xenopus laevis epidermis was carried out by a two step-incubation with different concentrations of NP-40. After discontinuous sucrose gradient centrifugation at 30,000 g for 60 min, a pure desmosomal fraction was obtained at 30%/40% interface. In the SDS-PAGE of isolated desmosomes, at least 12 bands (XDB1 to XDB12) were observed over a 75 kD region. Among them, three bands (XDB3, XDB7, XDB8; estimated MW 175, 124, and 112 kD respectively) were recognized as glycoproteins based on ConA binding. Monospecific polyclonal antibody against XDB3 cross-reacted with bovine Dsgs and vis-a-vis anti-bovine Dsgs with XDB3. By contrast, monospecific antibody against bovine Dsc a/b did not cross-react with either XDB7 or XDB8. Heterogeneous molecular constituents of desmosomal adhesion molecule, which have been observed among different bovine tissues, were confirmed in a phylogenetically different animal, Xenopus laevis. Combined results with other evidence could suggest an alternative system for desmosome-mediated cell adhesion.     

Stimulating the production of homoisoflavonoids in cell suspension cultures of Caesalpinia pulcherrima using cork tissue

It has previously been demonstrated that cork tissue increases the efficiency of the production of lipophilic secondary metabolites in diverse plant cell suspension cultures. In the present study, three new homoisoflavonoids--named dihydrobonducellin, 2'-methoxydihydrobonducellin, and 2'-methoxybonducellin--and bonducellin and isobonducellin were isolated from Caesalpinia pulcherrima cultured cells coincubated with cork tissue. Cork tissue increased the production of 2'-methoxybonducellin by about 7-fold relative to control cells, and more than 80% of the product was recoverable from the cork tissue. When cork tissue and methyl jasmonate or yeast extract were added simultaneously to the medium, the amount of 2'-methoxybonducellin produced increased further. The production of the other four homoisoflavonoids was enhanced by variable amounts. Our results indicate that the addition of cork tissue would be an effective technique for investigating formation of secondary metabolites that usually accumulate only in trace amounts.     

Overexpression of the barley aquaporin HvPIP2;1 increases internal CO(2) conductance and CO(2) assimilation in the leaves of transgenic rice plants

The internal conductance for CO(2) diffusion (g(i)) and CO(2) assimilation rate were measured and the related anatomical characteristics were investigated in transgenic rice leaves that overexpressed barley aquaporin HvPIP2;1. This study was performed to test the hypothesis that aquaporin facilitates CO(2) diffusion within leaves. The g(i) value was estimated for intact leaves by concurrent measurements of gas exchange and carbon isotope ratio. The leaves of the transgenic rice plants that expressed the highest levels of Aq-anti-HvPIP2;1 showed a 40% increase in g(i) as compared to g(i) in the leaves of wild-type rice plants. The increase in g(i) was accompanied by a 14% increase in CO(2) assimilation rate and a 27% increase in stomatal conductance (g(s)). The transgenic plants that had low levels of Aq-anti-HvPIP2;1 showed decreases in g(i) and CO(2) assimilation rate. In the plants with high levels of Aq-anti-HvPIP2;1, mesophyll cell size decreased and the cell walls of the epidermis and mesophyll cells thickened, indicating that the leaves had become xeromorphic. Although such anatomical changes could partially offset the increase in g(i) by the aquaporin, the increase in aquaporin content overcame such adverse effects.