Characterization of the adr1-1 nonsense mutation identifies the translational start of the yeast transcriptional activator ADR1

We have characterized a nonsense mutation in the ADR1 gene that identifies the translational start of the ADR1 protein. The ADR1 gene of Saccharomyces cerevisiae is required for synthesis of the glucose-repressible alcohol dehydrogenase (ADH2). The adr1-1 mutation, which inhibits ADH2 expression, was identified as a C to G transversion at base pair +32. This alteration would result in a UGA nonsense codon in place of a serine codon that would lead to termination of the ADR1 polypeptide after the 10th amino acid. The effect of the adr1-1 mutation was partially reversed by UGA-tRNA suppressors, indicating that the adr1-1 mutation affects ADR1 expression at the translational level. These observations establish that the first available AUG in the ADR1 sequence is used as the translational start site of ADR1. Tyrosine or leucine UGA-tRNA-suppressors resulted in levels of adr1-1 activity similar to that found for a serine UGA-tRNA-suppressor, suggesting that serine residue-11 is not essential to ADR1 function. Northern analyses showed that the 5.1 kb ADR1 mRNA was two- to three-fold more abundant when isolated from a strain carrying the ADR1 allele than from an isogenic strain containing the adr1-1 allele. These data confirm that the 5.1 kb mRNA is the ADR1 mRNA and suggest that inhibition of adr1-1 mRNA translation results in more rapid degradation of the adr1-1 mRNA.     

豆豉纤溶酶冻干保护剂的研究

采用正交试验对豆豉纤溶酶冻干保护剂进行了优化。分别以脱脂乳、乳糖、明胶为正交试验因素,以不同添加量为水平。试验结果表明,影响豆豉纤溶酶冻干后残余酶活力的保护剂的主次顺序为15%脱脂奶粉>1%明胶>6%乳糖。豆豉纤溶酶冻干保护剂的最佳组合为A2B4C1,即15%脱脂奶粉与6%乳糖的体积比为1:3;纤溶酶与保护剂的体积比为1:2;残余酶活力超过90%。     

trans-dominant mutations in the GPR1 gene cause high sensitivity to acetic acid and ethanol in the yeast Yarrowia lipolytica

Acetate non-utilizing strains harbouring trans-dominant mutations in the GPR1 gene (GPR1(d)) of the dimorphic yeast Yarrowia lipolytica have been selected and characterized. These mutants are highly sensitive to low concentrations of acetic acid and ethanol, even in presence of glucose. The toxic effect of acetic acid is pH-dependent and has the strongest effect at low pH. In contrast, the action of ethanol is pH-independent. One GPR1(d) mutant has been detected that was highly sensitive to acetic acid but could still grow on ethanol, which indicates putative differences in the function of the GPR1 gene product in the sensitivity to acetic acid and ethanol. The GPR1(d) mutants exhibit a complex pleiotropic phenotype. The mutations cause changed colony morphology as well as dimorphism of cells, and induce early cell death during growth on glucose, even without the presence of dicarbon compounds. Composition of intracellular membranes, as well as morphology of vacuole and mitochondria, were strongly changed. Back-crosses with wild-type strains and analysis of recombinant strains have shown that the expression of the pleiotropic phenotype depends on the site of mutation in the GPR1 gene, as well as on the genetic background of the strain harbouring the responsive mutation. Our data suggest that Gpr1p is involved in a general response of cells to the toxic action of dicarbon compounds like acetic acid and ethanol.     

A novel pyruvate kinase (PK-S) from boar spermatozoa is localized at the fibrous sheath and the acrosome

Boar spermatozoa contain a novel pyruvate kinase (PK-S) that is tightly bound at the acrosome of the sperm head and at the fibrous sheath in the principal piece of the flagellum, while the midpiece contains a soluble pyruvate kinase (PK). PK-S could not be solubilized by detergents, but by trypsin with no loss of activity. Purified PK-S as well as PK-S still bound to cell structures and soluble sperm PK have all kinetics similar to those of rabbit muscle PK-M1. The PK-S subunit had a relative molecular mass of 64 +/- 1 x 10(3) (n = 3), i.e. slightly higher than that of PK-M1, and carried an N-terminal extension (NH(2)-TSEAM-COOH) that is lacking in native PK-M1. Evidence is provided that PK-S is encoded by the PKM gene. Antibodies produced against the N-terminus of purified PK-S (NH(2)-TSEAMPKAHMDAG-COOH) were specific for PK-S as they did not react with somatic PKs or soluble sperm PK, while anti-PK-M1 recognized both sperm PKs. Immunofluorescence microscopy showed anti-PK-S to label the acrosome and the flagellar principal piece, whereas the midpiece containing the mitochondria was labelled only by anti-PK-M1. Immunogold labelling confirmed the localization of PK-S at the acrosome. In the principal piece, both polyclonal anti-PK-M1 and anti-PK-S were found at the fibrous sheath. Our results suggest that PK-S is a major component in the structural organization of glycolysis in boar spermatozoa.     

High-pressure treatment reduces the immunoreactivity of the major allergens in apple and celeriac

Scope: The impact of thermal and high pressure (HP) processing on the immunoreactivity of the allergens Mal d 1, Mal d 3 and Api g 1 has been investigated in apple and celeriac tissue, respectively. Methods and results: The extracted proteins were assessed using SDS‐PAGE and Western blot. The results showed that Mal d 1 was subject to loss of immunoreactivity as soon as the apple tissue was disrupted although it was remarkably resistant to both thermal and HP processing. This is in contrast to the Mal d 1 structural homolog from celeriac, Api g 1, that was susceptible to thermal processing. The other major allergen in apple, Mal d 3, was found to be resistant to chemical modification and thermal processing in apple, which is in contrast to behavior in solution. However, the combination of pressure and temperature significantly reduced its immunoreactivity. Pectin was found to protect Mal d 3 from thermal denaturation in solution and is a possible candidate for the protective effect of the fruit. Conclusion: The conclusion to be drawn from these results is that the combination of HP and thermal processing is an effective method to reduce the allergenicity of both apple and celeriac.     

Dhh1 is a member of the SESA network

The correct separation of chromosomes during mitosis is necessary to prevent genetic instability and aneuploidy, which are responsible for cancer and other diseases, and it depends on proper centrosome duplication. In a recent study, we found that Smy2 can suppress the essential role of Mps2 in the insertion of yeast centrosome into the nuclear membrane by interacting with Eap1, Scp160, and Asc1 and designated this network as SESA (S my2, E ap1, S cp160, A sc1). Detailed analysis showed that the SESA network is part of a mechanism which regulates translation of POM34 mRNA. Thus, SESA is a system that suppresses spindle pole body duplication defects by repressing the translation of POM34 mRNA. In this study, we performed a genome-wide screening in order to identify new members of the SESA network and confirmed Dhh1 as a putative member. Dhh1 is a cytoplasmic DEAD-box helicase known to regulate translation. Therefore, we hypothesized that Dhh1 is responsible for the highly selective inhibition of POM34 mRNA by SESA.     

The KlTrk1 gene encodes a low affinity transporter of the K+ uptake system in the budding yeast Kluyveromyces lactis

Potassium uptake in Saccharomyces cerevisiae is mediated by at least two proteins, known as Trk1p and Trk2p. Direct involvement in cation movements has been demonstrated for Trk1p, which is the high affinity transporter. S. cerevisiae cells also show low affinity potassium uptake, perhaps mediated by Trk2p. Mutants lacking Trk1p, lose high affinity system, but when grown with moderate potassium concentrations, Trk2p seems to replace it. Mutants lacking both proteins are viable but require at least 10 mM K(+) in the medium to sustain growth. Here we report the cloning and characterization of a gene from Kluyveromyces lactis encoding a homologue of these two proteins. KlTrkp is a 1070 amino acid peptide that shows, overall, higher homology with Trk2p than with Trk1p, and its disruption gives rise to cells with deficient potassium transport and with an increased K(+) requirement for normal growth. Determination of kinetic parameters in the K. lactis wild-type and Kltrk1Delta strains, as well as in Sctrk1Delta Sctrk2Delta S. cerevisiae cells expressing KlTrk1, indicated that this is a low affinity component of a major potassium uptake system in K. lactis.     

生态织物整理剂--聚醚/氨基硅油的性能研究

以聚醚／氨基硅油中的哌嗪基聚醚硅油PEAS-1为例，对其性能与氨乙基氨丙基硅油ASO-1、羧基硅油CAS-2、聚醚／环氧硅油CGF。进行了比较研究．结果表明：PEAS-1能与阴离子树脂、助剂配伍使用，柔软效果虽然不及ASO-1好，但能赋予织物理想的吸湿性、抗静电性能和耐洗性．PEAS-1整理的织物．经0．5％的汰渍洗衣粉-水洗涤10次后，静态吸水时间仍可达到3s56，而且室温放置多日吸湿性变化不大．     

Multicopy suppressors of the sly1 temperature-sensitive mutation in the ER-Golgi vesicular transport in Saccharomyces cerevisiae

Saccharomyces cerevisiae Sly1 protein is a member of the Sec1/Munc18-family proteins, which are essential for vesicular trafficking, but their exact biological roles are yet to be determined. A temperature-sensitive sly1 mutant arrests the vesicular transport from the ER to Golgi compartments at 37 degrees C. We screened for multicopy suppressor genes that restore the colony formation of the sly1(ts) mutant to discover functionally interacting components. The suppressor genes obtained were classified as: (1) those that encode a multifunctional suppressor, SSD1; (2) heat shock proteins, SSB1 and SSB2; (3) cell surface proteins, WSC1, WSC2 and MID2; (4) ER-Golgi transport proteins, USO1 and BET1; and (5) an as-yet-uncharacterized protein, HSD1 (high-copy suppressor of SLY1 defect 1). By epitope tagging of the gene product, we found that Hsd1 protein is an ER-resident membrane protein. Its overproduction induced enlargement of ER-like membrane structures.     

Relationship between the average projected area of corneocytes and the onset age of atopic dermatitis in childhood

In childhood, atopic dermatitis typically begins around 2--6 months of age. It is thought that the skin barrier dysfunction as well as allergic disease is important in the mechanism of atopic dermatitis. However, there are few reports of the skin barrier function in childhood. So we examined the relationship between the longitudinal surveys of the skin barrier function through the average projected area of corneocytes (APAc) and clinical findings in children from 1 to 12 months. As a result of examinations, APAc of cheek and upper arm in 1-month-old children is the same as those in adults, and APAc of cheek and upper arm decreases by 6 months of age. These results suggest that the skin barrier function decreases before or after the onset age of atopic dermatitis during childhood. Moreover, we examined APAc of children aged 0–5 for 1 year in the same nursery. APAc of upper arm in atopic dermatitis or atopic disposition has a significant difference compared with that of the other subjects in December. Furthermore, it was shown that change of APAc in the children under medical treatment was correlated with clinical findings. In conclusion, it was thought that the APAc shown as the index of skin barrier dysfunction is associated with the onset age of atopic dermatitis in childhood.     

食用固体油脂同质多晶现象的研究

本文报道了固体油脂中几种主要成分的同质多晶现象的研究结果。即多晶态的种类、熔点,多晶态间迁移规律,影响迁移速度的因素等。 通过对几种油脂样品的X射线衍射分析及熔点测定,明确了四种样品(POP、SOS、AOA、BOB)中均含有α、β′(除SOS外)、γ、Pseudo—β′、β_2、β_1、六种多晶态。α、β′均为二碳链长晶格,γ、Pseudo-β′、β_2、β_1、除POP外均为三碳链长结构,POP为二、三碳链长结构共存。β_2、β_1的侧面间隔特征图谱与可可脂的Ⅴ、Ⅵ型类似。β_1为热力学稳定体系,其余多晶态放置中会按上述顺序向β_1转化。 本研究为改善固体油脂制品的品质,特别是对提高巧克力、人造奶油等固体油脂食品的质量提供了理论依据。     

1-MCP对采后果实贮藏品质影响的研究进展

1-甲基环丙烯(1-MCP)为一种新型乙烯受体抑制剂,具有延缓果实衰老作用。它通过与乙烯受体蛋白的不可逆的竞争结合,干扰乙烯与其受体上的金属离子正常结合而在激素水平上影响果实对乙烯的响应。本文就1-MCP处理分别对呼吸跃变型和非呼吸跃变型果实采后生理及品质的效应以及对贮藏病害的影响进行了综述,旨为1-MCP绿色安全果实保鲜剂的应用推广提供技术思路。1-MCP对果实保鲜具有双向调节作用,1-MCP对采后果实的贮藏品质影响与其使用浓度、处理时间、处理方法及不同种类果实、呼吸漂移类型、采收期、贮藏温度等多种因素密切相关。     

Possible action of vasohibin-1 as an inhibitor in the regulation of vascularization of the bovine corpus luteum

The development of the corpus luteum (CL), which secretes large amounts of progesterone to establish pregnancy, is accompanied by active angiogenesis, vascularization, and lymphangiogenesis. Negative feedback regulation is a critical physiological mechanism. Vasohibin-1 (VASH1) was recently discovered as a novel endothelium-derived negative feedback regulator of vascularization. We therefore investigated the expression of VASH1 in the bovine CL. Expression of VASH1 mRNA and protein was predominantly localized to luteal endothelial cells (LECs). VASH1 expression in the CL was constant through the early to late luteal phases and decreased during CL regression relating with the action of luteolytic prostaglandin F(2)(α) in vivo. To investigate the role of VASH1, we determined whether VASH1 treatment affects angiogenesis and/or lymphangiogenesis using LECs and lymphatic endothelial cells (LyECs) in vitro. Vascular endothelial growth factor A (VEGFA) stimulated the expression of VASH1 in LECs but not in LyECs, and VASH1 completely blocked VEGFA-induced formation of capillary-like tube structures of LECs and LyECs in vitro. In summary, VASH1 is predominantly located on LECs in the bovine CL and inhibits the angiogenic and lymphangiogenic actions of VEGFA. Bovine CL therefore has a VEGFA-VASH1 system that may be involved in regulation of luteal function, especially in the development of the CL. The results indicate that VASH1 has the potential to act as a negative feedback regulator of angiogenesis and lymphangiogenesis in the CL in cows.     

粗机号线圈模数值的研究

主要研究了采用75%腈纶/25%羊毛混纺纱线编织的纬平针组织针织物和1+1罗纹组织针织物的线圈模数值。首先根据纬平针织物和1+1罗纹针织物的编织工艺进行编织,然后对织物进行拆除,测已知线圈个数的纱线总长度。最后根据公式计算出2种不同组织织物的线圈模数。实验结果表明:腈纶/羊毛纬平组织的模数值可初步标注为19.5,腈纶/羊毛1+1罗纹组织的模数值可初步标注为20.5,这对于控制纱线和坯布的张力波动,提高线圈长度均匀性,改善织物性能具有一定参考价值。