Sodium nitroprusside enhances callus induction and shoot regeneration in high value medicinal plant Canscora diffusa

Plant Cell, Tissue and Organ Culture (PCTOC) - In different countries, mostly in EU, rules for strawberry nursery propagation impose the use of micropropagation only to produce stock virus free...     

Synergistic effect of two β globin gene cluster mutations leading to the hereditary persistence of fetal hemoglobin (HPFH) phenotype

Co-inheritance of gamma and beta globin gene mutations in a compound heterozygous state is rare but of clinical interest as it provides an important data on understanding the HbF expression. Hematological analysis was carried out (Sysmex KX-21). F-cells were enumerated using flow cytometry. Beta globin gene was analysed by CRDB technique and by DNA sequencing. Gamma globin promoter region was sequenced and expression studies were carried out using real time Taqman assay. We report a family, where two inherited defects of the β globin gene cluster segregate. The proband and her sibling were compound heterozygotes for a novel ^Gγ promoter mutation and the 619 bp deletion a common Indian β thalassemia mutation. Molecular characterization revealed that the father (HbA₂ 5.1%, HbF 5.4%), proband (HbA₂ 3.6%, HbF 31.7%) and her brother (HbA₂ 3.9%, HbF 23.6%) were heterozygous for the 619 bp deletion. The mother (HbA₂ 2.1%, HbF 3.4%) had a normal β globin gene. As both the children showed high HbF levels, the γ globin gene work up was carried out. The ^Gγ-globin gene promoter analysis revealed that the mother and the two children were heterozygous for a 5 bp deletion -ATAAG (-533 to -529) that resides in the GATA binding site. These findings suggest that the 5 bp deletion in the ^Gγ globin promoter has a functional role in silencing the γ-globin gene expression in adults by disrupting GATA-1 binding and the associated repressor complex and results in the up-regulation of gamma globin gene expression. When co-inherited with β -thalassemia trait it leads to a phenotype of HPFH.     

FUS contributes to mTOR-dependent inhibition of translation

The amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD)–linked RNA-binding protein called FUS (fused in sarcoma) has been implicated in several aspects of RNA regulation, including mRNA translation. The mechanism by which FUS affects the translation of polyribosomes has not been established. Here we show that FUS can associate with stalled polyribosomes and that this association is sensitive to mTOR (mammalian target of rapamycin) kinase activity. Specifically, we show that FUS association with polyribosomes is increased by Torin1 treatment or when cells are cultured in nutrient-deficient media, but not when cells are treated with rapamycin, the allosteric inhibitor of mTORC1. Moreover, we report that FUS is necessary for efficient stalling of translation because deficient cells are refractory to the inhibition of mTOR-dependent signaling by Torin1. We also show that ALS-linked FUS mutants R521G and P525L associate abundantly with polyribosomes and decrease global protein synthesis. Importantly, the inhibitory effect on translation by FUS is impaired by mutations that reduce its RNA-binding affinity. These findings demonstrate that FUS is an important RNA-binding protein that mediates translational repression through mTOR-dependent signaling and that ALS-linked FUS mutants can cause a toxic gain of function in the cytoplasm by repressing the translation of mRNA at polyribosomes.     

Spectroscopical identification of residues of subunit G of the yeast V-ATPase in its connection with subunit E

A critical point in the V₁ sector and entire V₁V_O complex is the interaction of stalk subunits G (Vma10p) and E (Vma4p). Previous work, using precipitation assays, has shown that both subunits form a complex. In this work, we have analysed the N-terminal segment of subunit G (G_1–59) of the V₁V_O ATPase from Saccharomyces cerevisiae by using nuclear magnetic resonance (NMR) spectroscopy. Analyses of ¹H-¹⁵N heteronuclear single quantum coherence (HSQC) spectra of G_1–59 in the absence and presence of the N-terminal peptides E_1–18 and E_18–38 as well as the produced and purified C-terminal segment (E_39–233) shows specific interactions only with the peptide fragment E_18–38. The binding of this peptide occurs via the residues M₁, V₂, S₃, and K₅ as well for V₂₂, S₂₃, K₂₄, A₂₅ and R₂₆ of G_1–59. The specific E_18–38/G_1–59 binding has been confirmed by fluorescence correlation spectroscopy data. The E_18–38 peptide has been studied by CD spectroscopy and NMR. The 3D structure of this peptide adopts a stable helix-hinge-helix formation in solution. A model structure of the E_18–38/G_1–59 complex reveals the orientation of E_18–38 relative to G_1–59 via salt-bridges of the polar residues and van der Waals forces at the very N-terminus of both segments.     

Impediment to growth and yeast-to-hyphae transition in Candida albicans by copper oxide nanoparticles

Abstract

The effects of two prominent copper oxide nanoparticles (CuO-NP and Cu₂O-NP), with the oxidation state of Cu⁺⁺ (cupric) and Cu⁺ (cuprous), on Candida albicans were evaluated. CuO-NP and Cu₂O-NP were synthesized and characterized by XRD, FESEM, HR-TEM and Zeta potential. At sub-MIC (50?µg ml^?1), both cupric and cuprous oxide NPs prevented yeast-to-hyphae switching and wrinkling behaviour in C. albicans. The mechanism for the antifungal action of the two NPs differed; CuO-NP significantly elicited reactive oxygen species, whereas membrane damage was more pronounced with Cu₂O-NP. Real time PCR analysis revealed that CuO-NP suppressed the morphological switching of yeast-to-hyphae by down-regulating cph1, hst7 and ras1 and by up-regulation of the negative regulator tup1. In comparison, Cu₂O-NP resulted in down-regulation of ras1 and up-regulation of the negative regulators nrg1 and tup1. Between the two NPs, CuO exhibited increased antifungal activity due to its stable oxidation state (Cu⁺⁺) and its smaller dimensions compared with Cu₂O-NP.     

The shrubs of the Western Ghats (South India): floristics and status

Abstract. This study examines the understorey shrub community in a wet evergreen forest of South India. The shrub community in the evergreen forests of the Western Ghats, Eastern Ghats, Sri Lanka, South-east Asia, Neotropics, Africa and Madagascar are compared. The shrub community is richer in the Old World Tropics as compared to the Neotropics. The common families in the Old World Tropics are: Rubiaceae, Acanthaceae, Euphorbiaceae, Myrsinaceae and Annonaceae. The number of families constituting the understorey shrub community falls from forty-six (Western Ghats) to thirteen (Central Amazon). The study concludes that the evergreen forests in the Western Ghats probably have the richest understorey shrub community.
Résumé. L'étude concerne la communauté d'arbustes de sous-bois d'une forêt sempervirente du Sud de l'lnde. Les communautés d'arbustes dans les forèts sempervirentes des Ghâts Occidentaux, des Ghâts Orientaux, du Sri Lanka, du Sud-Est Asie, des Néotropiques, de l'Afrique et de Madagascar sont comparées. La communauté d'arbustes est plus riche dans le Vieux Monde Tropical que dans les Néotropiques. Les families communes dans le Vieux Monde Tropical sont; Rubiaceae, Acanthaceae, Euphorbiaceae, Myrsinaceae et Annonaceae. Le nombre de families constituant la communauté d'arbustes de sous-bois varie de 46 (Ghâts Occidentaux) à 13 (Amazonie Centrale). L'étude conclue que les forêts sempervierentes des Ghàts Occidentaux ont probablement la plus riche communauté d'arbustes de sois-bois.
Mots clés. Communauté d'arbustes de sous-bois, forêts sempervirentes, Ghâts Occidentaux, endémisme, Inde.