Molecular analyses of Toxoplasma gondii calmodulin-like domain protein kinase isoform 3

Ca²⁺ signaling is thought to play an important role in Toxoplasma gondii motility, including invasion of and egress from host cells. Recently, it has been reported that phosphorylation of the glideosome apparatus components of T. gondii occurs during invasion. To elucidate the role of T. gondii calmodulin-like domain protein kinase in the signaling pathway that bridges Ca²⁺ stimulation and motility, we characterized T. gondii calmodulin-like domain protein kinase isoform 3 (TgCDPKif3). TgCDPKif3 is homologous to Plasmodium falciparum calcium-dependent protein kinase 1, which has been reported to phosphorylate P. falciparum glideosome components. TgCDPKif3 was purified as a fusion protein that was labeled with [γ-³²P]ATP, and the label was subsequently removed by phosphatase treatment. Phosphorylation was eliminated when the putative catalytic lysine residue of TgCDPKif3 was replaced with alanine. TgCDPKif3 phosphorylated Histone II_AS as a representative substrate in a Ca²⁺-dependent manner at a high Ca²⁺ concentration. TgCDPKif3 was localized to the apical ends of tachyzoites. TgCDPKif3 showed the translocation between intra- and extracellular tachyzoites. TgCDPKif3 could phosphorylate T. gondii aldolase 1 (TgALD1) in vitro. The interaction between TgCDPKif3 and TgALD1 was confirmed by the co-immunoprecipitation assay in mammal cells. We suggested that TgCDPKif3 could participate in the motility of T. gondii through the phosphorylation of glideosome complex member.     

DnaJs,the critical drivers of Hsp70s: genome-wide screening,characterization and expression of DnaJ family genes in Sorghum bicolor

Molecular Biology Reports - The DnaJ/Hsp40s, are important components in the chaperone machine, and play pivotal roles in plant growth, development and stress tolerance. Sorghum, the semi-arid...     

Overexpression of [delta]-Pyrroline-5-Carboxylate Synthetase Increases Proline Production and Confers Osmotolerance in Transgenic Plants

Proline (Pro) accumulation has been correlated with tolerance to drought and salinity stresses in plants. Therefore, overproduction of Pro in plants may lead to increased tolerance against these abiotic stresses. To test this possibility, we overexpressed in tobacco the mothbean [delta]-pyrroline-5-carboxylate synthetase, a bifunctional enzyme able to catalyze the conversion of glutamate to [delta]-pyrroline-5-carboxylate, which is then reduced to Pro. The transgenic plants produced a high level of the enzyme and synthesized 10- to 18-fold more Pro than control plants. These results suggest that activity of the first enzyme of the pathway is the rate-limiting factor in Pro synthesis. Exogenous supply of nitrogen further enhanced Pro production. The osmotic potentials of leaf sap from transgenic plants were less decreased under water-stress conditions compared to those of control plants. Overproduction of Pro also enhanced root biomass and flower development in transgenic plants under drought-stress conditions. These data demonstrated that Pro acts as an osmoprotectant and that overproduction of Pro results in the increased tolerance to osmotic stress in plants.     

Optimization of a <Emphasis Type="Italic">Bacopa monnieri</Emphasis>-based genetic transformation model for testing the expression efficiency of pathway gene constructs of medicinal crops

A fast regenerating Agrobacterium tumefaciens-mediated transformation protocol for Bacopa monnieri (L.) Wettst. was developed as a model system for heterologous expression of terpenoid indole alkaloid pathway genes from Catharanthus roseus (L.) G. Don. The direct regeneration of shoots from leaf explants co-cultured with A. tumefaciens resulted in the integration of a tryptophan decarboxylase (tdc) and strictosidine synthase (str) cassette (<hpt-<Tdc2-<Str-gus>) in the regenerated progeny. The highest transformation efficiency (83.88%) was achieved when leaf explants were infected on the adaxial laminar surface by manual pricking with 48- to 72-h-old suspensions (OD₆₀₀ = 0.5–0.6) of A. tumefaciens strain LBA1119 (carrying the binary vector pMOG22). The heterologous expression of tryptophan decarboxylase and strictosidine synthase genes that are otherwise not present in B. monnieri plants was confirmed through semi-quantitative PCR and metabolite quantification assays. The entire protocol duration from co-cultivation through regeneration of transgenic plants to their establishment in the glass house took 40–45 d. The developed B. monnieri model can be used to test expression cassettes carrying genes for plant secondary metabolic pathway engineering, especially those genes that are expressed in differentiated cell, tissue, or organs.     

Improved activity and stability of Rhizopus oryzae lipase via immobilization for citronellol ester synthesis in supercritical carbon dioxide

In present work, Rhizopus oryzae lipase immobilized on a film prepared using blend of hydroxylpropyl methyl cellulose (HPMC) and polyvinyl alcohol (PVA) was investigated for synthesis of citronellol esters with supercritical carbon dioxide (Sc-CO₂) as a reaction medium. The transesterification reaction was optimized for various reaction parameters like effect of molar ratio, acyl donor, time, temperature, enzyme concentration, effect of pressure and co-solvent to achieve the maximum yield of desired product. The results obtained signify remarkable increment (about eightfold) in the yield of citronellol acetate (91%) as compared to that of free lipase (11%) in Sc-CO₂. The developed biocatalytic methodology provides a substantial advantage of low biocatalyst loading (1.5%, w/v), lower reaction temperature (45 °C) and lower pressure (8 MPa) as compared to previous reports. The immobilization method has significantly enhanced the operational stability of lipase for ester synthesis under Sc-CO₂ conditions. The developed methodology was successfully applied for synthesis of three different industrially important citronellol esters namely citronellol acetate (91%), citronellol butyrate (98%), citronellol laurate (99%) with excellent yields using vinyl esters as acyl donor under Sc-CO₂ conditions. In addition, the immobilized biocatalyst was effectively recycled for three consecutive recycles.     

Dendrobium tamenglongense sp. nov. (Orchidaceae) from Manipur,India

Dendrobium tamenglongense R. Kishor, Y. N. Devi, H. B. Sharma, J. Tongbram & S. P. Vij sp. nov. from Manipur, India is described and illustrated as a new species. The new species differs from D. jaintianum in having larger and glabrous leaves with acute apices, green sepal apices, a 1–3‐flowered inflorescence, smaller and non‐fragrant flowers and a 3‐lobed labellum with fimbriate midlobe.     

The history of the discovery of blood circulation: unrecognized contributions of Ayurveda masters

Ayurveda, the native healthcare system of India, is a rich resource of well-documented ancient medical knowledge. Although the roots of this knowledge date back to the Vedic and post-Vedic eras, it is generally believed that a dedicated branch for healthcare was gradually established approximately between 400 BCE and 200 CE. Probably because the language of documentation of these early textbooks is in Sanskrit, a language that is not in day-to-day use among the general population even in India, many significant contributions of Ayurveda have remained unrecognized in the literature related to the history of medicine. In this communication, the discovery of blood circulation has been taken up as a case, and a few important references from the representative Ayurveda compendia that hint at a preliminary understanding of the cardiovascular system as a "closed circuit" and the heart acting as a pump have been reviewed. The central argument of this review is that these contributions from Ayurveda too must be recorded and credited when reviewing the milestones in the history of medicine, as Ayurveda can still possibly guide various streams of the current sciences, if revisited with this spirit.