Abiotic stress induces change in Cinnamoyl CoA Reductase (CCR) protein abundance and lignin deposition in developing seedlings of Leucaena leucocephala

Aboitic stress such as drought and salinity are class of major threats, which plants undergo through their lifetime. Lignin deposition is one of the responses to such abiotic stresses. The gene encoding Cinnamoyl CoA Reductase (CCR) is a key gene for lignin biosynthesis, which has been shown to be over-expressed under stress conditions. In the present study, developing seedlings of Leucaena leucocephala (Vernacular name: Subabul, White popinac) were treated with 1 % mannitol and 200 mM NaCl to mimic drought and salinity stress conditions, respectively. Enzyme linked immunosorbant assay (ELISA) based expression pattern of CCR protein was monitored coupled with Phlorogucinol/HCl activity staining of lignin in transverse sections of developing L. leucocephala seedlings under stress. Our result suggests a differential lignification pattern in developing root and stem under stress conditions. Increase in lignification was observed in mannitol treated stems and corresponding CCR protein accumulation was also higher than control and salt stress treated samples. On the contrary CCR protein was lower in NaCl treated stems and corresponding lignin deposition was also low. Developing root tissue showed a high level of CCR content and lignin deposition than stem samples under all conditions tested. Overall result suggested that lignin accumulation was not affected much in case of developing root however developing stems were significantly affected under drought and salinity stress condition.Keyword: Abiotic stress, Cinnamoyl CoA reductase, Developing seedlings, Leucaena leucocephala     

An immunological epitope selective for pathological monomer-misfolded SOD1 in ALS

Misfolding of Cu/Zn-superoxide dismutase (SOD1) is emerging as a mechanism underlying motor neuron degeneration in individuals with amyotrophic lateral sclerosis (ALS) who carry a mutant SOD1 gene (SOD1 ALS). Here we describe a structure-guided approach to developing an antibody that specifically recognizes monomer-misfolded forms of SOD1. We raised this antibody to an epitope that is normally buried in the SOD1 native homodimer interface. The SOD1 exposed dimer interface (SEDI) antibody recognizes only those SOD1 conformations in which the native dimer is disrupted or misfolded and thereby exposes the hydrophobic dimer interface. Using the SEDI antibody, we established the presence of monomer-misfolded SOD1 in three ALS mouse models, with G37R, G85R and G93A SOD1 mutations, and in a human individual with an A4V SOD1 mutation. Despite ubiquitous expression, misfolded SOD1 was found primarily within degenerating motor neurons. Misfolded SOD1 appeared before the onset of symptoms and decreased at the end stage of the disease, concomitant with motor neuron loss.     

Structural Differences between Pri-miRNA Paralogs Promote Alternative Drosha Cleavage and Expand Target Repertoires

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Growth‐associated protein 43 promotes thyroid cancer cell lines progression via epithelial‐mesenchymal transition

Thyroid cancer is maintaining at a high incidence level and its carcinogenesis is mainly affected by a complex gene interaction. By analysis of the next‐generation resequencing of paired papillary thyroid cancer (PTC) and adjacent thyroid tissues, we found that Growth Associated Protein 43 (GAP43), a phosphoprotein activated by protein kinase C, might be novel markers associated with PTC. However, its function in thyroid carcinoma has been poorly understood. We discovered that GAP43 was significantly overexpressed in thyroid carcinoma and these results were consistent with that in The Cancer Genome Atlas (TCGA) cohort. In addition, some clinicopathological features of GAP43 in TCGA database showed that up‐regulated GAP43 is significantly connected to lymph node metastasis (P < 0.001) and tumour size (P = 0.038). In vitro experiments, loss of function experiments was performed to investigate GAP43 in PTC cell lines (TPC‐1 and BCPAP). The results proved that GAP43 knockdown in PTC cell significantly decreased the function of cell proliferation, colony formation, migration, and invasion and induced cell apoptosis. Furthermore, we also indicated that GAP43 could modulate the expression of epithelial‐mesenchymal transition‐related proteins, which could influence invasion and migration. Put those results together, GAP43 is a gene which was associated with PTC and might be a potential therapeutic target.     

Water Crystallisation of Model Sugar Solutions with Nanobubbles Produced from Dissolved Carbon Dioxide

This study was conducted to examine the influence of CO₂ nanobubbles on crystallisation behaviour of water during freezing of model sugar (2–5%w/v) solutions. CO₂ gas was dissolved at 0, 1000, and 2000-ppm concentrations before freezing. Carbonated sugar solutions in 50 mL plastic tubes were immersed in a pre-cooled (−15 °C) ethylene glycol bath and left to freeze at −15 °C for 90 min. When the temperature of the solutions reached 0 °C, ultrasound (US; 20 kHz) was emitted in the bath for 20 s duration through a metal horn transducer. The US wave applied in the ethylene glycol bath was expected to propagate to the sugar solutions in the tube and promote gas bubble formation from dissolved CO₂, which will trigger the ice nucleation. Obtained freezing curves were analysed for nucleation time and temperature, supercooling degree, and time taken for phase change. In general, the CO₂ gas promoted freezing of water, causing a noticeable shift in nucleation parameters. For example, nucleation time of 2000-ppm carbonated water coupled with sonication emission for 20 s (7.8 min) was much shorter than that of controls (pure water without any treatment = 19.1 min and US only = 14.3 min). The former initiated ice nucleation just below sub-zero temperature (−0.2 °C) whereas the onset temperature of controls (pure water without any treatment = −11.3 °C and the US only treatment = −10.3 °C). A similar effect was observed with different model sugar solutions. The current findings can be applied to refine the manufacturing process of ice-cream and frozen desserts by the food industries.

     

Analysis of 11,430 recombinant protein production experiments reveals that protein yield is tunable by synonymous codon changes of translation initiation sites

Recombinant protein production is a key process in generating proteins of interest in the pharmaceutical industry and biomedical research. However, about 50% of recombinant proteins fail to be expressed in a variety of host cells. Here we show that the accessibility of translation initiation sites modelled using the mRNA base-unpairing across the Boltzmann’s ensemble significantly outperforms alternative features. This approach accurately predicts the successes or failures of expression experiments, which utilised Escherichia coli cells to express 11,430 recombinant proteins from over 189 diverse species. On this basis, we develop TIsigner that uses simulated annealing to modify up to the first nine codons of mRNAs with synonymous substitutions. We show that accessibility captures the key propensity beyond the target region (initiation sites in this case), as a modest number of synonymous changes is sufficient to tune the recombinant protein expression levels. We build a stochastic simulation model and show that higher accessibility leads to higher protein production and slower cell growth, supporting the idea of protein cost, where cell growth is constrained by protein circuits during overexpression.     

RNA silencing suppressor activity of Velvet bean severe mosaic begomovirus DNA-A encoded proteins

Velvet bean severe mosaic virus (VbSMV) is a bipartite DNA virus infecting Mucuna pruriens (Velvet bean), belongs to the genus Begomovirus in the family Geminiviridae. Velvet bean is a medicinal plant of enormous medicinal value. In the present study, it was delineated that proteins encoded by VbSMV viz. AV2 (pre-coat protein), AC2 (TrAP), AV1 (coat protein) are suppressors of RNA silencing as identified through Agrobacterium co-infiltration assays using Nicotiana benthamiana as a host plant. AV2 showed strong suppressor activity whereas AC1 and AV1 were found to be weak suppressors. To the best of our knowledge, this is the first report on identification of suppressor of RNA silencing encoded by VbSMV infecting a medicinal plant.     

Increased localization of APP‐C99 in mitochondria‐associated ER membranes causes mitochondrial dysfunction in Alzheimer disease

In the amyloidogenic pathway associated with Alzheimer disease (AD), the amyloid precursor protein (APP) is cleaved by β‐secretase to generate a 99‐aa C‐terminal fragment (C99) that is then cleaved by γ‐secretase to generate the β‐amyloid (Aβ) found in senile plaques. In previous reports, we and others have shown that γ‐secretase activity is enriched in mitochondria‐associated endoplasmic reticulum (ER) membranes (MAM) and that ER–mitochondrial connectivity and MAM function are upregulated in AD. We now show that C99, in addition to its localization in endosomes, can also be found in MAM, where it is normally processed rapidly by γ‐secretase. In cell models of AD, however, the concentration of unprocessed C99 increases in MAM regions, resulting in elevated sphingolipid turnover and an altered lipid composition of both MAM and mitochondrial membranes. In turn, this change in mitochondrial membrane composition interferes with the proper assembly and activity of mitochondrial respiratory supercomplexes, thereby likely contributing to the bioenergetic defects characteristic of AD.