Isolation of new nonconditional Saccharomyces cerevisiae mutants defective in asparagine-linked glycosylation

We describe the isolation and partial characterization of Saccharomycescerevisiae nonconditional mutants that show defects in N-glycosylationof proteins. The selection method is based on the reductionof affinity for the ion exchanger QAE-Sephadex as a consequenceof the decrease in the negative charge of the cell surface.This characteristic reflects a decrease in the incorporationof mannosyl-phosphate units into the N-linked oligosaccharidesof the mannoproteins. The mutants exhibit low affinity for thebasic dye alcian blue and for that reason we have called themldb (low dye binding) mutants. Eight of the complementationgroups seem to be new as shown by complementation studies withpreviously isolated mutants of similar phenotype. Four of thegroups showed a significant reduction in the number and/or sizeof the N-linked oligosaccharides attached to secreted invertase.We have analyzed the N-linked oligosaccharides of ldb1 and ldb2,the mutants that show the most drastic reduction in the affinityfor the alcian blue dye. In both cases, the purified endo H-releasedoligosaccharides from the mannoproteins lacked detectable amountsof phosphate groups as shown by ion exchange chromatographyand the ¹H NMR spectra. In addition, ldb1 synthesizes a truncatedand unbranched outer chain lacking any     

Role of manuring in control of root-rot of guar (Cyamopsis psoralioides dc.) and wilt of gram (Cicer arietinum L.) caused by sclerotium rolfsii Sacc.

Summary Root-rot of guar (Cyamopsis psoralioides DC.) and wilt of gram (Cicer arietinum L.) caused bySclerotium rolfsii Sacc. are important diseases in the province of Uttar Pradesh in India. The two diseases were significantly reduced by manuring the garden soil with municipal farm manure (compost). Disease incidence in root-rot of guar was 71.9 % in the untreated garden soil. When the soil was mixed with double the amount of compost, only 54.7 % root-rot was observed. Similarly, 82.1 % wilt was noticed in gram in untreated garden soil and addition of compost in 1:1 ratio (soil:compost) significantly reduced the disease to 64.3 %. Heavy manuring is recommended for controlling the two diseases to a considerable extent.A part of Ph. D. thesis submitted by the senior author to Agra University, Agra, India.     

Effect of diazinon in male rats. Histopathological and biochemical studies.

Mild structural and functional changes were observed in liver and testes of rats after a single intraperitoneal administration of diazinon (21.6 mg/kg). Kidney, however, showed no pathological lesion. Attempts are made to correlate the pathological changes in these organs with the activity of succinic dehydrogenase, adenosine triphosphatase and alkaline phosphatase.     

Plant RABs: Role in Development and in Abiotic and Biotic Stress Responses

Endosomal trafficking plays an integral role in various eukaryotic cellular activities and is vital for higher-order functions in multicellular organisms. RAB GTPases are important proteins that influence various aspects of membrane traffic, which consequently influence many cellular functions and responses. Compared to yeast and mammals, plants have evolved a unique set of plant-specific RABs that play a significant role in their development. RABs form the largest family of small guanosine triphosphate (GTP)-binding proteins, and are divided into eight sub-families named RAB1, RAB2, RAB5, RAB6, RAB7, RAB8, RAB11 and RAB18. Recent studies on different species suggest that RAB proteins play crucial roles in intracellular trafficking and cytokinesis, in autophagy, plant microbe interactions and in biotic and abiotic stress responses. This review recaptures and summarizes the roles of RABs in plant cell functions and in enhancing plant survival under stress conditions.     

Enhancing the production of scopoletin and quercetin 3-O-β-d-glucoside from cell suspension cultures of Tilia americana var. mexicana by modulating the copper and nitrate concentrations

Plant Cell, Tissue and Organ Culture (PCTOC) - The aerial tissues of Tilia americana var. mexicana produce compounds with anxiolytic activity, such as quercetin 3-O-β-d-glucoside and...     

Poly(ε-L-lysine): Synthesis and conformation

The synthesis of poly(ε-L -lysine) is described. This is a poly(ε-amino acid) in which the ε-amino group of lysine is condensed with the α-carboxyl group to produce a chain backbone that is a variant of the usual one seen in proteins and the side chain is the α-amino group. Conformational studies of poly(ε-L -lysine) and its t-butyloxycarbonyl derivative suggest the likelihood of a chain order that is formally similar to the antiparallel pleated-sheet conformation of proteins.