Structural and functional analysis of a chloroplast transit peptide : interactions with the chloroplast translocation apparatus

Protein targeting into organelles is a central cellular process that occurs in allliving organisms. Proper cellular targeting is essential for the functioning of most proteins within a cell, yet the mechanism by which this process is mediated is not clearly understood. Plastids from plants provide an excellent model system for studying protein targeting as they are semi-autonomous organelles with a wide variety of structural and functional diversity. Although, plastids have their own genome they strongly rely on imported proteins that are encoded in the nuclear genome and translated in the cytoplasm. The proteins synthesized in the cytoplasm have an N-terminal extension called the transit peptide, which is considered to be necessary and sufficient for the import of proteins into plastids. Binding of precursors to the plastid surface probably involves both proteins and lipids of the envelope membrane. Several proteins in the outer and inner membrane of chloroplasts have been identified as components of the chloroplast translocation machinery. These proteins form the Toe (Iranslocon at the QUter-envelope-membrane of £.hloroplasts) components and the Tic CTranslocon at the inner-envelope-membrane of £.hloroplasts) components

Structural and functional analysis of a chloroplast transit peptide : interactions with the chloroplast translocation apparatus

Protein targeting into organelles is a central cellular process that occurs in allliving organisms. Proper cellular targeting is essential for the functioning of most proteins within a cell, yet the mechanism by which this process is mediated is not clearly understood. Plastids from plants provide an excellent model system for studying protein targeting as they are semi-autonomous organelles with a wide variety of structural and functional diversity. Although, plastids have their own genome they strongly rely on imported proteins that are encoded in the nuclear genome and translated in the cytoplasm. The proteins synthesized in the cytoplasm have an N-terminal extension called the transit peptide, which is considered to be necessary and sufficient for the import of proteins into plastids. Binding of precursors to the plastid surface probably involves both proteins and lipids of the envelope membrane. Several proteins in the outer and inner membrane of chloroplasts have been identified as components of the chloroplast translocation machinery. These proteins form the Toe (Iranslocon at the QUter-envelope-membrane of £.hloroplasts) components and the Tic CTranslocon at the inner-envelope-membrane of £.hloroplasts) components

Optimal Reasoning of Opposing Non-functional Requirements based on Game Theory

Goal-Oriented Requirement Engineering is a modeling technique that represents software system requirements using goals as goal models. In a competitive environment, these requirements may have opposing objectives. Therefore, there is a requirement for a goal reasoning method, which offers an alternative design option that achieves the opposing objectives of inter-dependent actors. In this paper, a multi-objective zero-sum game theory-based approach is applied for choosing an optimum strategy for dependent actors in the i* goal model. By integrating Java with IBM CPLEX optimisation tool, a simulation model based on the proposed method was developed. A successful evaluation was performed on case studies from the existing literature. Results indicate that the developed simulation model helps users to choose an optimal design option feasible in real-time competitive environments

AHP based Optimal Reasoning of Non-functional Requirements in the i∗ Goal Model

Goal-Oriented Requirements Engineering (GORE) has been found to be a valuable tool in the early stages of requirements engineering. GORE plays a vital role in requirements analysis like alternative design/ goal selection during decision-making. The decision-making process of alternative design/ goal selection is performed to assess the practicability and value of alternative approaches towards quality goals. Majority of the GORE models manage alternative selection based on qualitative approach, which is extremely coarse-grained, making it impossible for separating two alternatives. A few works are based on quantitative alternative selection, yet this does not provide a consistent judgement on decision-making. In this paper, Analytic Hierarchy Process (AHP) is modified to deal with the evaluation of selecting the alternative strategies of inter-dependent actors of i∗ goal model. The proposed approach calculates the contribution degrees of alternatives to the fulfilment of top softgoals. It is then integrated with the normalized relative priority values of top softgoals. The result of integration helps to evaluate the alternative options based on the requirements problem against each other. To clarify the proposed approach, a simple telemedicine system is considered in this paper

Novel natural withanolides induce apoptosis and inhibit migration of neuroblastoma cells through down regulation of N-myc and suppression of Akt/mTOR/NF-κB activation

Despite recent advances in intensive chemotherapy treatments, long-term success is achieved in less than 30% of children with high-risk neuroblastoma (NB). Key regulatory pathways including the PI3K/Akt, mTOR and NF-κB are implicated in the pathogenesis of NB. Although drugs targeting these individual pathways are in clinical trials, they are not effective due to the activation of compensatory mechanisms. We have previously reported that natural novel withanolides from Physalis longifolia can potently inhibit these key regulatory pathways simultaneously. In the present study, we examined the efficacy and mechanisms through which novel withanolides and their acetate derivatives (WGA-TA and WGB-DA) from P.longifolia kill NB cells. The results from the study demonstrated that our novel acetate derivatives are highly effective in inhibiting the proliferation, shifting the cell cycle and inducing apoptosis in a dose dependent manner. Analysis of oncogenic pathway proteins targeted by withanolides indicated induction of heat shock response due to oxidative stress. Dose dependent decrease in clients of HSP90 chaperone function due to suppression of Akt, mTOR, and NF-κB pathways led to decrease in the expressions of target genes such as cyclin D1, N-myc and Survivin. Additionally, there was a dose dependent attenuation of the migration and invasion of NB cells. Furthermore, the lead compound WGA-TA showed significant reduction in tumor growth of NB xenografts. Taken together, these results suggest that withanolides are an effective therapeutic option against NBs

Effect of scheduling of drip irrigation on growth, yield and water use efficiency of turmeric (Curcuma longa L.) var. CO 2

Field experiments were conducted during 2012–13 and 2013–14 at Horticulture College and Research Institute, Coimbatore (Tamil Nadu) on black clay loam soil to study the effect of scheduling of drip irrigation on the growth, yield and water use efficiency of turmeric (cv. CO 2). The experiment included two intervals and three levels of irrigation with surface irrigation as control. Significantly higher rhizome yield was recorded in one day interval of irrigation at 80% PE (T2) (42.79 t ha-1) which was on par with two days interval of irrigation at 80% PE (T3) (42.51 t ha-1). Significantly higher number of leaves, leaf area, number of tillers, plant height and dry matter production were recorded in T2 and T3 compared to flood irrigation. Both one day and two days interval of irrigation and 40% PE recorded significantly higher WUE. The intervals and levels of irrigation were significantly superior for WUE, compared to surface irrigation. &nbsp

Role of sintering temperature dependent crystallization of bioactive glasses on erythrocyte and cytocompatibility

Bioglass (BG) was prepared by sol-gel method and the role of sintering temperatures (600, 700 and 800 °C) on crystalline phase changes, bioactivity, erythrocyte and MG-63 cell line compatibility was investigated. Increase in sintering temperature from 600 to 800 °C led to the secondary phase formation that was confirmed through structural analysis. Micrographics revealed the formation of nanorods (700 °C) and nanoflake like (800 °C) morphologies. Biocompatibility assay showed that, BG sintered at 600 °C had optimal biocompatibility while better mechanical property was noted at 700 °C. Altogether, the study demonstrated that increasing the sintering temperature will result in increased crystallinity which in turn resulted in the optimal biomineralization but decreased the biocompatibility. Hence, we demonstrated the importance of temperature during the processing of BG for various applications, as it affects many properties including bioactivity and compatibility

Combination Treatment of Withalongolide a Triacetate with Cisplatin Induces Apoptosis by Targeting Translational Initiation, Migration, and Epithelial to Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma

Treatment regimens for head and neck squamous cell carcinoma (HNSCC) typically include cisplatin and radiotherapy and are limited by toxicities. We have identified naturally derived withalongolide A triacetate (WGA-TA) from Physalis longifolia as a lead compound for targeting HNSCC. We hypothesized that combining WGA-TA with cisplatin may allow for lower, less toxic cisplatin doses. HNSCC cell lines were treated with WGA-TA and cisplatin. After treatment with the drugs, the cell viability was determined by MTS assay. The combination index was calculated using CompuSyn. The expression of proteins involved in the targeting of translational initiation complex, epithelial to mesenchymal transition (EMT), and apoptosis were measured by western blot. Invasion and migration were measured using the Boyden-chamber assay. Treatment of MDA-1986 and UMSCC-22B cell lines with either WGA-TA or cisplatin alone for 72 h resulted in a dose dependent decrease in cell viability. Cisplatin in combination with WGA-TA resulted in significant synergistic cell death starting from 1.25 μM cisplatin. Combination treatment with WGA-TA resulted in lower cisplatin dosing while maintaining the downregulation of translational initiation complex proteins, the induction of apoptosis, and the blockade of migration, invasion, and EMT transition. These results suggest that combining a low concentration of cisplatin with WGA-TA may provide a safer, more effective therapeutic option for HNSCC that warrants translational validation

Synthesis and Biological Evaluation of Novobiocin Core Analogues as Hsp90 Inhibitors

Development of heat shock protein 90 (Hsp90) C‐terminal inhibitors has emerged as an exciting strategy for the treatment of cancer. Previous efforts have focused on modifications to the natural products novobiocin and coumermycin. Moreover, variations in both the sugar and amide moieties have been extensively studied, whereas replacements for the coumarin core have received less attention. Herein, 24 cores were synthesized with varying distances and angles between the sugar and amide moieties. Compounds that exhibited good anti‐proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity, were those that placed the sugar and amide moieties between 7.7 and 12.1 Å apart along with angles of 180°.Angle of attack: The distance and angle between the N‐methylpiperidine and the biaryl side chain was analyzed in an effort to develop more potent Hsp90 C‐terminal inhibitors. Compounds that exhibited good anti‐proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity were those that placed the sugar and amide moieties between 7.7 and 12.1 Å apart along with angles of 180°.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136281/1/chem201504955_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136281/2/chem201504955.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136281/3/chem201504955-sup-0001-misc_information.pd