Nuclear RNA Surveillance in \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e: Trf4p-dependent Polyadenylation of Nascent Hypomethylated tRNA and an Aberrant Form of 5S rRNA

1-Methyladenosine modification at position 58 of tRNA is catalyzed by a two-subunit methyltransferase composed of Trm6p and Trm61p in Saccharomyces cerevisiae. Initiator tRNA (tRNAiMet) lacking m1A58 (hypomethylated) is rendered unstable through the cooperative function of the poly(A) polymerases, Trf4p/Trf5p, and the nuclear exosome. We provide evidence that a catalytically active Trf4p poly(A) polymerase is required for polyadenylation of hypomethylated tRNAiMet in vivo. DNA sequence analysis of tRNAiMet cDNAs and Northern hybridizations of poly(A)+ RNA provide evidence that nascent pre-tRNAiMet transcripts are targeted for polyadenylation and degradation. We determined that a mutant U6 snRNA and an aberrant form of 5S rRNA are stabilized in the absence of Trf4p, supporting that Trf4p facilitated RNA surveillance is a global process that stretches beyond hypomethylated tRNAiMet. We conclude that an array of RNA polymerase III transcripts are targeted for Trf4p/ Trf5p-dependent polyadenylation and turnover to eliminate mutant and variant forms of normally stable RNAs

The GL_2 main conjecture for elliptic curves without complex multiplication

The main conjectures of Iwasawa theory provide the only general method known at present for studying the mysterious relationship between purely arithmetic problems and the special values of complex L-functions, typified by the conjecture of Birch and Swinnerton-Dyer and its generalizations. Our goal in the present paper is to develop algebraic techniques which enable us to formulate a precise version of such a main conjecture for motives over a large class of p-adic Lie extensions of number fields. The paper ends by formulating and briefly discussing the main conjecture for an elliptic curve E over the rationals Q over the field generated by the coordinates of its p-power division points, where p is a prime greater than 3 of good ordinary reduction for E.Comment: 39 page

FREE-RADICAL SCAVENGING ACTIVITY LEAF EXTRACT OF LITSEA LAEVIGATA GAMBLE

Objective: In the present study, antioxidant activity in the leaf of the pet-ether, chloroform, acetone and methanolic extracts from Litsea laevigata Gamble. Leaf was investigated by employing established in vitro studies. L. laevigata belongs to the Lauraceae family. Methods: The capability of the plant extract to act as hydrogen/electrons donor or scavenger of radicals were determined by in vitro antioxidant assays using 2,2-diphenyl-2-picrylhydrazyl free radical (DPPH.) scavenging, reducing power assay, superoxide radical (O2*-) scavenging activity, phosphomolybdenum assay, FRAP, ABT and metal chelating activity were performed to know the antioxidant potency of the plant extract of leaves of L. laevigata. Results: Results are evaluated higher in leaf extract of L. laevigata recorded total phenol, total flavonoid, and tannin. The present state of work was designed to evaluate the phytochemical, antioxidant in the plant leaf extracts of L. laevigata. The plant L. laevigata methanolic extract of leaf showed greater IC50 antioxidant activity of DPPH assay (5.264 µg/ml) and compare to other extract, higher phosphomolybdenum reduction (164.36 mg/g), better Reducing power activity leaf in methanol (0.711%), higher ferric reducing power (4060.66MmolFe(II)E/mg), and higher in superoxide radical scavenging activity in (78.12 mg/ml). However, the better metal chelating ability was shown by the water extracts of the leaf (5.145 EDTAE/100g) compared to other solvent extracts. Conclusion: The result indicates the total phenol and antioxidant activity potential of L. laevigata

Caste Discrimination at Marupakkam Novel

Caste is another name for the basic social control of society. Earlier there were classes by profession. Then he started doing business in succession. Then based on profession, caste emerged and developed. Man has reached a state of high and low. An upper caste is reduced to a lower caste. The purpose of this article is to explore this

Intend Of Viscous Dryers And The Use Of Plastic Waste On Viscous Floors

The primary purpose of the design of this road is to provide a smooth surface for passing vehicles as the wells are less inclined. That is why it is uncomfortable and causes a lot of confusion. Plastic waste and its disposal are major environmental hazards as they cause pollution and landslides. The use of plastic waste in bibulous mixtures will improve its properties and strength 1. In addition, it will also be a solution to remove various plastics and defects by means, such as holes, amplifiers, pipes etc. It is organized due to the combination of hot and mixed tar and can be used to repair the road. This will not only strengthen the road but also increase its durability. Titanium dioxide is used as a smoke detector that absorbs smoke from cars. This new technology will benefit the hot climate in India. It is economic and environmental. In this paper we talk about the nature of the soil to be considered when designing sidewalks, repairing sidewalks, making it easier to process and smoking plastic cigarettes

Software Test Automation with Robot Framework

Testing is a crucial activity in Software Development Process. It is to examine & modify source code. Effective Testing produces high quality software. To improve the quality and the efficiency of software testing, software automation test has been used widely during the software testing. This paper discusses the advantages of testing tools in software test automation, with the Robot framework

Nuclear Surveillance and Degradation of Hypomodified Initiator tRNA\u3csup\u3eMet\u3c/sup\u3e in \u3cem\u3eS. cerevisiae\u3c/em\u3e

The tRNA m1A58 methyltransferase is composed of two subunits encoded by the essential genes TRM6 and TRM61 (formerly GCD10 and GCD14). The trm6-504 mutation results in a defective m1A methyltransferase (Mtase) and a temperature-sensitive growth phenotype that is attributable to the absence of m1A58 and consequential tRNAiMet instability. We used a genetic approach to identify the genes responsible for tRNAiMet degradation in trm6 cells. Three recessive extragenic mutations that suppress trm6-504 mutant phenotypes and restore hypomodified tRNAiMet to near normal levels were identified. The wild-type allele of one suppressor, DIS3/RRP44, encodes a 3′-5′ exoribonuclease and a member of the multisubunit exosome complex. We provide evidence that a functional nuclear exosome is required for the degradation of tRNAiMet lacking m1A58. A second suppressor gene encodes Trf4p, a DNA polymerase (pol σ) with poly(A) polymerase activity. Whereas deletion of TRF4 leads to stabilization of tRNAiMet, overexpression of Trf4p destabilizes the hypomodified tRNAiMet in trm6 cells. The hypomodified, but not wild-type, pre-tRNAiMet accumulates as a polyadenylated species, whose abundance and length distribution both increase upon Trf4p overexpression. These data indicate that a tRNA surveillance pathway exists in yeast that requires Trf4p and the exosome for polyadenylation and degradation of hypomodified pre-tRNAiMet

Qualitative analysis of interspecific hybrids of oil palm for bunch components and fatty acid composition

Elaeis oleifera or the American oil palm produces more liquid oil due to higher unsaturated fatty acid content compared to the commercial species Elaeis guineensis. However, due to erratic and poor yield, E. oleifera is not cultivated commercially. Interspecific hybrids are having the potentiality of combining yield and quality in the oil. Seven interspecific crosses were made involving six E. guineensis and five E. oleifera palms. These were evaluated for their bunch component and oil quality in terms of fatty acid composition along with control E. guineensis tenera (D X P) hybrids and E. oleifera parental palms. Bunch component analysis showed intermediate values for bunch weight as well as bunch related parameters including proportion of parthenocarpic fruits. However, the oil/mesocarp and oil/bunch were lower than those of the parents. Fatty acid composition showed intermediate value between the two parental species for all the fatty acids. Wide variability in fatty acid composition was found in progenies of two specific interspecific crosses. No correlation was observed between any two fatty acids. Out of seven interspecific crosses, three were found to be on par with the better performing E. oleifera parental palms with respect to fatty acids. Since performance of each palm is different, individual interspecific hybrid palm was assessed based on total unsaturated fatty acids and oleic acid content and 20 superior palms were selected, which could be employed for further back crossing programme to combine the quality of palm oil and yield

A STUDY ON QUANTITY OF Bt TOXIN IN Bt AND NBt COTTON RHIZOSPHERE

Genetically engineered plants and their residues may pose direct or indirect impacts on different ecosystem functions. The aim of this experiment was to determine the amount of Bt toxin (Cry 1 Ac δ endotoxin) present in the rhizosphere of Bt cotton during the crop period at regular intervals. Bt toxin was estimated from the rhizospheric soils of near isogenic Non Bt cotton crop for as a control. Cry 1 Ac δ endotoxin was estimated using Envirologix Quanti Kit plate (ELISA) method. The soil samples were collected in which Bt cotton was cultivating for more than ten years as monocrop, similarly Non Bt cotton fields where never cultivated transgenic crop were selected for this study. The quantity of the Cry 1Ac toxin levels in the rhizosphere of Bt cotton was estimated at different crop stages and it was 41.13 ppb at pre cultivation stage which is higher than that of Non Bt rhizosphere soil i.e.15.3 ppb. The toxin concentration increased gradually during different crop stages i.e 69.32 ppb, 95.24 ppb, 103.35 ppb at 30, 60,90 days crop stages respectively. It was decreased to 92.37 ppb at harvest stage and shown higher levels (173.24 ppb) at postharvest stage. But in case of Non Bt rhizosphere it is almost same at all the stages of crop. The results suggests that there is a significant difference between the Bt and Non Bt soils with respect to quantity of Cry toxin and there is also significant difference between different crop stages of Bt cotton with respect to Non Bt cotto

Mutation induced enhanced biosynthesis of lipase

The purpose of the present investigation is to enhance production of biomedically important enzyme lipase by subjecting the indigenous lipase producing strain Rhizopus sp. BTS-24 to improvement by natural selection and random mutagenesis (UV and N-methyl-N'-nitro-N-nitroso guanidine, NTG). The isolation of mutants and the lipolytic activity of selected mutants were described. The best natural selectant BTNS12 showed 110% higher lipase activity than the wild strain (BTS-24). The lipase yield of the best UV mutant BTUV3 was 164% higher than the parent strain (BTNS12) and 180% times higher than the wild strain (BTS-24). Also, the lipase yield of the best NTG mutant BTNT2 was 133 % higher than the parent strain (BTUV3) and 232% higher than the wild strain (BTS-24). The results indicated that UV and NTG were effective mutagenic agents for strain improvement of Rhizopus sp. BTS-24 for enhanced lipase productivity. Key Words: Lipase, Rhizopus, UV, NTG. African Journal of Biotechnology Vol.3(11) 2004: 618-62