Targeted movement of cell end factors in fission yeast

Kinesins are microtubule-based motor proteins that transport cargo to specific locations within the cell. However, the mechanisms by which cargoes are directed to specific cellular locations have remained elusive. Here, we investigated the in vivo movement of the Schizosaccharomyces pombe kinesin Tea2 to establish how it is targeted to microtubule tips and cell ends. Tea2 is loaded onto microtubules in the middle of the cell, in close proximity to the nucleus, and then travels using its intrinsic motor activity primarily at the tips of polymerizing microtubules. The microtubule-associated protein Mal3, an EB1 homologue, is required for loading and/or processivity of Tea2 and this function can be substituted by human EB1. In addition, the cell-end marker Tea1 is required to anchor Tea2 to cell ends. Movement of Tea1 and the CLIP170 homologue Tip1 to cell ends is abolished in Tea2 rigor (ATPase) mutants. We propose that microtubule-based transport from the vicinity of the nucleus to cell ends can be precisely regulated, with Mal3 required for loading/processivity, Tea2 for movement and Tea1 for cell-end anchoring.     

Chinese green tea lowers cholesterol level through an increase in fecal lipid excretion

Lung Chen Tea, a Chinese green tea, has been found to lower serum and liver cholesterol. In this study, its dose response and mechanisms of action on cholesterol lowering in diet-induced hypercholesterolemic Sprague-Dawley rats were investigated. The activities of three major lipid metabolizing enzymes, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-Co A) reductase, cholesterol 7alpha-hydroxylase and fatty acid synthase (FAS), as well as fecal excretion of bile acids and cholesterol were examined. Lung Chen Tea administration for eight weeks significantly lowered the serum cholesterol in the 2% and 4% groups. The activities of the three enzymes were not affected by Lung Chen Tea, but the fecal bile acids and cholesterol excretions were significantly increased. These results demonstrated that Lung Chen Tea lowered plasma cholesterol by increasing fecal bile acids and cholesterol excretion. Further investigation is required to evaluate the exact mechanisms of action of Lung Chen Tea.     

Antibacterial activity of essential oils on the growth of Staphylococcus aureus and measurement of their binding interaction using optical biosensor

Antibacterial activity of essential oils (Tea tree, Chamomile, Eucalyptus) on Staphylococcus aureus growth was evaluated as well as the essential oil-loaded alginate beads. The binding interactions between the cell and the essential oils were measured using an optical biosensor. The antibacterial activity of the essential oils to the cell was evaluated with their binding interaction and affinity. The antibacterial activity appeared in the order of Tea Tree> Chamomile>Eucalyptus, in comparison of the inhibition effects of the cell growth to the essential oils. The association rate constant and affinity of the cell binding on Tea Tree essential oil were 5.0 x 10(-13) ml/(CFU-s) and 5.0 x 10(5) ml/CFU, respectively. The affinity of the cell binding on Tea Tree was about twice higher than those on the other essential oils. It might be possible that an effective antibacterial activity of Tea Tree essential oil was derived from its strong adhesive ability to the cell, more so than those of the other essential oils.     

5种茶园秋冬季天敌与假眼小绿叶蝉空间关系密切程度的差异

为了明确与假眼小绿叶蝉空间关系密切的天敌种类,为合理利用和保护天敌提供科学依据。运用地学统计学分析方法计算白毫早茶园、黄山大叶种茶园、农抗早茶园、平阳特早茶园和乌牛早茶园秋冬季假眼小绿叶蝉和其主要6种天敌地统计学半变异函数的变程。使用灰色系统分析方法对计算结果进行灰色关联度分析,并对分析结果进行标准化。以标准化后的密切指数大小评判天敌与假眼小绿叶蝉空间关系的密切程度。结果是：1）、黄山大叶种茶园和农抗早茶园与假眼小绿叶蝉空间关系密切的前3位天敌是粽管巢蛛、鳞纹肖蛸和斜纹猫蛛,但位次不同。2）、白毫早茶园前3位天敌是鳞纹肖蛸、斜纹猫蛛和锥腹肖蛸,前2种与黄山大叶种和农抗早茶园相同。3）、平阳特早茶园前3位天敌是鳞纹肖蛸、粽管巢蛛和草间小黑蛛,前2种与黄山大叶种和农抗早茶园相同。4）、乌牛早茶园前3位天敌是粽管巢蛛、草间小黑蛛和三突花蟹蛛,只有粽管巢蛛与黄山大叶种和农抗早茶园相同。根据5种茶园同种天敌密切指数之和以及同种天敌位次之和评判,与假眼小绿叶蝉空间关系密切的天敌均是鳞纹肖蛸、粽管巢蛛和斜纹猫蛛。天敌位次的变化主要是害虫和天敌数量之比的比值变化。害虫个体数与某种天敌个体数之比的比值越小,天敌与害虫的跟随关系则越密切。密切原因与食饵资源短缺有关。     

贵州苦丁茶植物资源及化学成分分析

苦丁茶是我国南方各民族长期饮用的一类植物代用茶。在贵州,苦丁茶原植物有６科６属９种,主流品种为木樨科女贞属植物粗壮女贞〔Ｌｉｇｕｓｔｒｕｍｒｏｂｕｓｔｕｍ（Ｒｏｘｂ．）Ｂｌ．〕。分析了贵州５种苦丁茶植物叶的主要化学成分并和绿茶进行了对比,分析结果表明,苦丁茶类植物是一种营养成分含量丰富,不含咖啡因的营养保健的功能性饮料新资源     

Wsh3/Tea4 is a novel cell-end factor essential for bipolar distribution of Tea1 and protects cell polarity under environmental stress in S. pombe

BACKGROUND: The fission yeast Schizosaccharomyces pombe has a cylindrical cell shape, for which growth is strictly limited to both ends, and serves as an excellent model system for genetic analysis of cell-polarity determination. Previous studies identified a cell-end marker protein, Tea1, that is transported by cytoplasmic microtubules to cell tips and recruits other cell-end factors, including the Dyrk-family Pom1 kinase. The deltatea1 mutant cells cannot grow in a bipolar fashion and show T-shaped morphology after heat shock. RESULTS: We identified Wsh3/Tea4 as a novel protein that interacts with Win1 MAP kinase kinase kinase (MAPKKK) of the stress-activated MAP kinase cascade. Wsh3 forms a complex with Tea1 and is transported to cell tips by growing microtubules. The deltawsh3 mutant shows monopolar growth with abnormal Tea1 aggregate at the non-growing cell end; this abnormal aggregate fails to recruit Pom1 kinase. Consistent with the observed interaction between Win1 and Wsh3, cells lacking Wsh3 or Tea1 show more severe cell-polarity defects under osmolarity and heat-stress stimuli that are known to activate the stress MAPK cascade. Furthermore, mutants of the stress MAPK also exhibit cell-polarity defects when exposed to the same stress. CONCLUSIONS: Wsh3/Tea4 is an essential component of the Tea1 cell-end complex. In addition to its role in bipolar growth during the normal cell cycle, the Wsh3-Tea1 complex, together with the stress-signaling MAPK cascade, contributes to cell-polarity maintenance under stress conditions.     

The kelch repeat protein,Tea1, is a potential substrate target of the p21-activated kinase,Shk1, in the fission yeast,Schizosaccharomyces pombe

The p21-activated kinase (PAK) homolog, Shk1, is a critical component of a multifunctional Ras/Cdc42/PAK complex required for viability, polarized growth and cell shape, and sexual differentiation in the fission yeast, Schizosaccharomyces pombe. Substrate targets of the Shk1 kinase have not previously been described. Here we show that the S. pombe cell polarity factor, Tea1, is directly phosphorylated by Shk1 in vitro. We demonstrate further that Tea1 is phosphorylated in S. pombe cells and that its level of phosphorylation is significantly reduced in cells defective in Shk1 function. Consistent with a role for Tea1 as a potential downstream effector of Shk1, we show that a tea1 null mutation rescues the Shk1 hyperactivity-induced lethal phenotype caused by loss of function of the essential Shk1 inhibitor, Skb15. All phenotypes associated with Skb15 loss, including defects in actin cytoskeletal organization, chromosome segregation, and cytokinesis, are suppressed by tea1 Delta, suggesting that Tea1 is a potential mediator of multiple Shk1 functions. S. pombe cells carrying a weak hypomorphic allele of shk1 together with a tea1 Delta mutation exhibit a cytokinesis defective phenotype that is significantly more severe than that observed in the respective single mutants, providing evidence that Shk1 and Tea1 cooperate to regulate cytokinesis. In addition, we show that S. pombe cells carrying the orb2-34 allele of shk1 exhibit a pattern of monopolar growth similar to that observed in tea1 Delta cells, suggesting that Shk1 and Tea1 may regulate one or more common processes involved in the regulation of polarized cell growth. Taken together, our results strongly implicate Tea1 as a potential substrate-effector of the Shk1 kinase.     

崂山茶区茶树根围AM真菌多样性

为调查崂山茶区土壤中丛枝菌根(AM)真菌资源的分布状况, 于2007年9月从青岛崂山茶区12个茶园采集茶树(Camellia sinensis)根围土样, 采用湿筛倾注–蔗糖离心法分离AM真菌, 测定其物种丰度、频度、孢子密度、相对多度、重要值、多样性指数等。共分离到AM真菌3属22种, 无梗囊霉属(Acaulospora)出现的频度最高, 其次是球囊霉属(Glomus)。AM真菌孢子密度以晓望村茶园最高, 高家村茶园最低; 种丰度以常家村茶园最高; 常家村茶园和万来客茶园的Shannon-Wiener指数显著高于其他茶园。光壁无梗囊霉(Acaulospora laevis)是北崂茶厂、万里江茶园、樱山春茶园、万里江有机茶园、常家村茶园和桑园村茶园的优势种; 波状无梗囊霉(Acaulospora undulata)为万里江有机茶园和万来客茶园的优势种; 隐球囊霉(Glomus occultum)为樱山春茶园、晓望村茶园和万来客茶园的优势种。应用典型相关分析(CCA)对环境因子与崂山茶区AM真菌群落组成的关系进行了分析, 各因子的影响大小依次为: 土壤速效磷含量＞土壤有机质含量＞种植年限＞土壤碱解氮含量＞土壤pH值＞土壤速效钾含量。     

Tea3p is a cell end marker activating polarized growth in Schizosaccharomyces pombe

Eukaryotic cells are often polarized in their cytoplasmic structures, and this can be important for their function. The fission yeast Schizosaccharomyces pombe is a highly polarized cell that extends bipolarly along a single axis to generate a rod-shaped cell. It divides by medial fission to generate two equal-sized daughter cells that resume growth only at the old end. Once these cells have reached a particular length, they undergo NETO, new end take-off, whereby growth is activated at the other end to generate bipolarly extending cells. The activation and positioning of these growth zones are essential for maintaining growth in a straight line. Genetic analyses have identified many proteins involved in this process, like the cell end markers Tea1p and Pom1p and the kinases Orb2p/Shk1p/Pak1, Ssp1p, and Wee1p. Here, we describe tea3, a gene encoding a tea1-like protein with some similarities to ERM proteins. Tea3p is required for efficient NETO and for the proper placement of the septum. Like Pom1p, Tea3p localizes to cell ends, and its localization depends on microtubules and Tea1p. We propose that Tea3p is a novel cell end marker required specifically to activate polarized cell growth at the second end during NETO.     

中国各茶类中主要芳香物质组成及其在加工过程中的变化

祁门红茶、龙井茶、茉莉花茶、白兰花茶和乌龙茶,不仅是中国的名优茶,而且也是主要出口茶类。这些名茶芳香馥郁,品质独特,与其含有大量芳香物质密切相关。本文综合有关研究成果,简要概述了这五类名优茶中主要芳香物质构成、特点及变化。     

Race,Ideology, and the Tea Party: A Longitudinal Study

The Tea Party movement, which rose to prominence in the United States after the election of President Barack Obama, provides an ideal context in which to examine the roles of racial concerns and ideology in politics. A three-wave longitudinal study tracked changes in White Americans’ self-identification with the Tea Party, racial concerns (prejudice and racial identification), and ideologies (libertarianism and social conservatism) over nine months. Latent Growth Modeling (LGM) was used to evaluate potential causal relationships between Tea Party identification and these factors. Across time points, racial prejudice was indirectly associated with movement identification through Whites’ assertions of national decline. Although initial levels of White identity did not predict change in Tea Party identification, initial levels of Tea Party identification predicted increases in White identity over the study period. Across the three assessments, support for the Tea Party fell among libertarians, but rose among social conservatives. Results are discussed in terms of legitimation theories of prejudice, the “racializing” power of political judgments, and the ideological dynamics of the Tea Party.     

What potential is there for regeneration of native species from the soil seed bank in Coast Tea Tree‐dominated scrub?

Shrub encroachment generally causes the loss of native species in herbaceous‐dominated communities. The ability of the original ecosystem to return to its pre‐encroachment state (i.e. its ecological resilience) will be partially contingent on the capacity of these species to regenerate from soil‐stored seed. Coast Tea Tree (Leptospermum laevigatum) has formed a dense scrub in many areas previously dominated by grassy woodland, and hence, managers need guidance about the effectiveness of strategies designed to recover the pre‐encroachment vegetation. In this context, we ask: what is the potential of species stored in the soil seed bank to return following Tea Tree removal? A germination experiment was undertaken using soil collected from dense stands of Tea Tree that had been long established. Heat/smoke was applied to soils to simulate the effects of a fire on the soil seed bank, while leaf litter treatments were used to mimic both undisturbed stands and stands where shrubs have been slashed where litter creates a physical barrier to emergence. We found the soil seed bank was dominated by exotic forbs (83% of all germinants) and contained few grasses. Heat and smoke decreased total species density but increased species diversity through the suppression of common exotics. Our data suggest that slashing would result in germination being dominated by exotic flora, but using fire would likely reduce that dominance. However, we conclude that recovery by much of the original flora after site occupation by Coast Tea Tree may be contingent on mechanisms other than soil‐stored seeds.     

The EB1 homolog Mal3 stimulates the ATPase of the kinesin Tea2 by recruiting it to the microtubule

Tea2 is a kinesin family member from Schizosaccharomyces pombe that is targeted to microtubule tips and cell ends in a process that depends on Mal3. Constructs of Tea2 containing the motor domain only or the motor domain plus the N-terminal extension are monomeric, whereas a construct including the first predicted coiled coil region is dimeric. These constructs have a low basal rate of ATP hydrolysis of <0.1 s(-1), but microtubules stimulate the rate of ATP hydrolysis to a maximum of approximately 15 s(-1). Hydrodynamic analysis of Mal3 indicates that it is dimeric. Mal3 is known to associate with Tea2, and analysis with the above Tea2 constructs indicates that the principal site of interaction of Mal3 with Tea2 is the N-terminal extension, although a weaker interaction is also observed with the motor domain alone. In parallel to the binding studies, Mal3 strongly stimulates the ATPase of constructs containing the N-terminal extension by decreasing the K0.5(MT) for stimulation by microtubules but only weakly stimulates motor domains without the N-terminal extension. Mal3 reduces the K0.5(MT) values without affecting the k(cat) value at saturating microtubule level. Binding of Mal3 to microtubules induces an increase in the binding of Tea2 and a reciprocal stimulation of Mal3 binding by Tea2 is also observed. Tea2 is a plus end directed motor that drives sliding of axonemes when adsorbed to a glass surface. The sliding rate is initially unaffected by Mal3, but axonemes stop moving on continued exposure to Mal3.     

游猎蛛在茶尺蠖高峰日的种间竞争作用

为了合理保护和充分利用天敌,明确茶园游猎蛛天敌捕食茶尺蠖Ectropis obliqua hypulina的种间竞争力及其差异。本文运用通经分析法、灰色关联度分析法、竞争系数分析法及竞争强度指数分析法对龙井43、黄山大叶种、乌牛早、安吉白茶、平阳特早和农抗早6类茶园中茶尺蠖高峰日时的7种游猎蛛捕食茶尺蠖的种间竞争作用进行分析。结果表明,按相关系数比较,乌牛早茶园茶尺蠖与条纹蝇虎Plexippus setipet的相关系数为-0.888,平阳特早茶园茶尺蠖与三突花蟹蛛Misumenops tricuspidatus和斜纹猫蛛Oxyopes Sertatws的相关系数分别为0.981和-0.902,均达相关水平,天敌间鞍型花蟹蛛Xysticus ephippiafus、三突花蟹蛛、斑管巢蛛Clubiona reichlini和斜纹猫蛛均与黑色跳蛛Plexippus paykulli相关,鞍型花蟹蛛、粽管巢蛛Clubiona japonicola和黑色跳蛛均与三突花蟹蛛相关。用灰色关联度法分析,与茶尺蠖数量上关系密切的前4种天敌依次是三突花蟹蛛、粽管巢蛛、黑色跳蛛和鞍型花蟹蛛。按竞争系数大小...     

Studies on the Aroma Constituents of Fuiien Ti Kuan Yin Tea,Se Chung Tea,Wu-I Shui Hsien Tea and Wu-I Chi Chung Tea in China

This paper reports, for the first time, the aroma constituents of the famous Fujian Oolong tea—Ti kuan Yin Tea, Se Chung Tea, Wu-I Shut Hsien Tea and Wu-I Chi Chung Tea. 70 aroma concentrates of tea samples were identified by the use of (IC-MS, SCOT capillary coumn GC standard sample addition method and IR. Among which benzyl alcohol, translinalooloxide (furanoid), cis-linalooloxide (fuconoid), 3,7-dimeihy-l,5, 7-octatrien-3-ol, β-phenylethanol, translinalooloxide (pyranoid), geraniol, indole, eisjasmone, pasmine laetone, nerolidol and mthyl jasmonate are the typical character the aroma constituents. Consequently the aroma is varied by different varieties of the tea, different regions of their growth and different processing.     

绿茶对人胃癌细胞株中p21,p53蛋白表达的影响

应用免疫细胞化学方法检测ＳＧＣ—７９０１胃癌细胞株中ｐ２１、ｐ５３蛋白的表达,以探讨绿茶的抗癌作用机理。结果表明：绿茶提取物明显抑制ＳＧＣ—７９０１胃癌细胞株中ｐ２１ｒａｓ、ｐ５３蛋白的表达,并有剂量效应。提示绿茶对ｐ２１、ｐ５３基因突变可能有修复作用     

<Emphasis Type="Italic">Ilex Vomitoria</Emphasis> Ait. (Yaupon): A Native North American Source of a Caffeinated and Antioxidant-Rich Tea

Ilex Vomitoria Ait. (Yaupon): A Native North American Source of a Caffeinated and Antioxidant-Rich Tea. Yaupon holly (Ilex vomitoria Ait.) is a caffeine-containing shrub native to the southeastern United States where its leaves and twigs were traditionally used to prepare a stimulating and healthful beverage by Amerindians and more recent colonists. For a variety of mostly socioeconomic and cultural reasons, widespread consumption of yaupon tea ceased by the late 19th century, but the species is widely used in ornamental horticulture. Given the environmental damage associated with other caffeine crops, we believe that disuse of this species is unfortunate, and we report on traits that consumers may consider valuable. We found that total foliar biomass, caffeine, and antioxidant production all increased with nitrogen fertilization in one common ornamental yaupon cultivar, ‘Nana.’ Increasing light availability was associated with increased antioxidant activity but not with the decreased caffeine production predicted by the carbon/nutrient balance hypothesis for secondary metabolite production. We also found the highest caffeine concentrations in another yaupon cultivar, ‘Pendula,’ but suggest that the wide range of chemical variation offered by wild-type yaupon populations renders them more suitable as sources for the development of high caffeine-producing varieties. The results of this study suggest that yaupon is a viable caffeine alternative for North Americans living within its range on the southeastern coastal plain.     

Tea and health: the underlying mechanisms

Detailed multidisciplinary research on the effect of tea and the associated tea polyphenols has led to major advances on the underlying mechanisms. In most studies, green and black tea have similar effects, four of which are reviewed in this paper. 1) Tea polyphenols are powerful antioxidants that may play a role in lowering the oxidation of LDL-cholesterol, with a consequent decreased risk of heart disease, and also diminish the formation of oxidized metabolites of DNA, with an associated lower risk of specific types of cancer. 2) Tea and tea polyphenols selectively induce Phase I and Phase II metabolic enzymes that increase the formation and excretion of detoxified metabolites of carcinogens. 3) Tea lowers the rate of cell replication and thus the growth and development of neoplasms. 4) Tea modifies the intestinal microflora, reducing undesirable bacteria and increasing beneficial bacteria. The accumulated knowledge suggests that regular tea intake by humans might provide an approach to decrease the incidence of and mortality from major chronic diseases.     

小儿感冒茶的薄层鉴别和定量测定研究

目的为制定小儿感冒茶(山银花、板蓝根、重楼)的质量控制方法。方法用TCL鉴别山银花、板蓝根、重楼。用高效液相色谱法测定小儿感冒茶中绿原酸的含量。结果通过方法学考察,绿原酸检测浓度在0.244~1.952μg范围内与峰面积积分值呈良好的线性关系,加样回收率为99.22%,RSD%=0.92(n=2)。结论实验应用方法简便准确、重现性好、精密度高。所建质量标准可用于小儿感冒茶的质量控制。     

都匀毛尖茶的应用历史与研究现状

都匀毛尖茶具有悠久的应用历史和独特品质及品牌价值,然而现代研究较少。本文对都匀毛尖茶(Duyun Maojian Tea)的发展历史、应用现状、生产工艺、化学成分和栽培育种等方面进行了较全面的综述,为都匀毛尖茶的进一步深入研究和开发提供参考。