Gut Microbes Egested during Bites of Infected Sand Flies Augment Severity of Leishmaniasis via Inflammasome-Derived IL-1β

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Context sequences of translation initiation codon in plants

In this survey of 5074 plant genes for their AUG context sequences, purines are present at the _3 and +4 positions in about 80% of the sequences. Although this observation is similar to the vertebrate consensus sequence, the number of plant mRNAs with purines at the _3 position is lower and at the +4 position is higher than reported for vertebrate mRNAs. Higher plants have an AC-rich consensus sequence, caA(A/C)aAUGGCg as a context of translation initiator codon. Between the two major groups of angiosperms, the context of the AUG codon in dicot mRNAs is aaA(A/C)aAUGGCu which is similar to the higher-plant consensus but monocot mRNAs have c(a/c)(A/G)(A/C)cAUGGCG as a consensus which exhibits an overall similarity with the vertebrate consensus. The experimental evidence regarding the importance of the AUG context in plants is discussed.     

Ontogenetic changes in growth and net photosynthetic rate of two peanut (Arachis hypogaea L.) cultivars

The ontogenetic changes in growth, and the diurnal changes in net photosynthetic rate (P_N) and stomatal conductance were studied in two peanut cultivars of different habit groups. Significant cultivar differences were noticed: the prostrate cv. M 13 was found superior to the erect cv. J 11 in all the parameters studied. Specific leaf mass and the rates of gross photosynthesis and respiration were higher in cv. M 13 than in cv. J 11. In vegetative phase, the maximum P_N was in cv. J 11, but in pod filling phase, it was in cv. M 13. The differences in growth and P_N of the cultivars were significant after the onset of reproductive sink. Therefore, the screening for higher P_N has to be made at the pod-filling phase, and between 09.00 and 10.00 of the day (at optimum temperature).     

Conserved sequence motifs in plant S-adenosyl-L-methionine-dependent methyltransferases

Plant S-adenosyl-L-methionine-dependent methyltransferases (SAM-Mtases) are the key enzymes in phenylpropanoid, flavonoid and many other metabolic pathways of biotechnological importance. Here we compiled the amino acid sequences of 56 SAM-Mtases from different plants and performed a computer analysis for the conserved sequence motifs that could possibly act as SAM-binding domains. To date, genes or cDNAs encoding at least ten distinct groups of SAM-Mtases that utilize SAM and a variety of substrates have been reported from higher plants. Three amino acid sequence motifs are conserved in most of these SAM-Mtases. In addition, many conserved domains have been discovered in each group of O-methyltransferases (OMTs) that methylate specific substrates and may act as sites for substrate specificity in each enzyme. Finally, a diagrammatic representation of the relationship between different OMTs is presented. These SAM-Mtase sequence signatures will be useful in the identification of SAM-Mtase motifs in the hitherto unidentified proteins as well as for designing primers in the isolation of new SAM-Mtases from plants.     

Molecular modeling,in silico screening and molecular dynamics of PfPRL-PTP of P. falciparum for identification of potential anti-malarials

Millions of deaths occur every year due to malaria. Growing resistance against existing drugs for treatment of malaria has exaggerated the problem further. There is an intense demand of identifying drug targets in malaria parasite. PfPRL-PTP protein is PRL group of phosphatase, and one of the interesting drug targets being involved in three important pathways of malaria parasite (secretion, phosphorylation, and prenylation). Therefore, in this study, we have modeled three-dimensional structure of PfPRL-PTP followed by validation of 3D structure using RAMPAGE, verify3D, and other structure validation tools. We could identify 12 potential inhibitory compounds using in silico screening of NCI library against PfPRL-PTP with Glide. The molecular dynamics simulation was also performed using GROMACS on PfPRL-PTP model alone and PfPRL-PTP-inhibitor complex. This study of identifying potential drug-like molecules would add up to the process of drug discovery against malaria parasite.     

Ultrastructural localization of ATPase activity in cotton fiber during elongation

Summary The ultrastructural distribution of potassium chloride stimulated adenosine triphosphatase activity was investigated in the outer integument of a linted cultivar of cotton and a lintless (naked seed) mutant from one day preanthesis to eight days postanthesis by using a heavy metal simultaneous capture reaction technique. No enzyme activity other than in mitochondria was observed in the lintless mutant. In the linted cultivar no ATP-specific enzyme activity was seen in non-elongating epidermal cells, subepidermal cells of the outer integuments or any controls. As fiber initials started elongating, enzyme activity gradually appeared on the tonoplasts of enlarging vacuoles. Heavier lead phosphate deposits were observed on the membrane of small vacuoles compared to the tonoplast. This activity continued at least to eight days postanthesis. The enzyme inhibitor, N,N-dicyclohexylcarbodiimide inhibited, while KCl stimulated, tonoplast ATPase activity. The gradual increase of ATPase activity on the tonoplast of expanding fibers, but not on the tonoplasts of non-fiber cells, suggests the active transport of osmotically active compounds, presumably potassium and malate, into the vacuoles of expanding fibers. Fusion of smaller vacuoles with the large central vacuole indicates that these structures contribute additional membrane components along with their enzyme activity to the tonoplast of expanding fibers. The occurrence of ATPase activity, of ER-derived vesicular structures, and the organized pattern of deposition of these structures on the tonoplast indicate ER-originated ATPase activity. This study supports the theory of osmoregulation in cotton fiber where ATPase provides the energy for active accumulation of osmotically active compounds, (K⁺, malate) into the vacuoles, thereby generating and maintaining the turgor pressure required for fiber expansion.Abbreviations ATPase Adenosine triphosphatase - DCCD N,N-Di-cyclohexylcarbodiimide - EM Electron microscope - ER Endoplasmic reticulum - GP -Glycerophosphate - LC Lead citrate - PEP-Case Phosphoenolpyruvate carboxylase - UA Uranyl acetate