De novo transcriptome analysis of an imminent biofuel crop, Camelina sativa L. using Illumina GAIIX sequencing platform and identification of SSR markers.

Camelina sativa L. is an emerging biofuel crop with potential applications in industry, medicine, cosmetics and human nutrition. The crop is unexploited owing to very limited availability of transcriptome and genomic data. In order to analyse the various metabolic pathways, we performed de novo assembly of the transcriptome on Illumina GAIIX platform with paired end sequencing for obtaining short reads. The sequencing output generated a FastQ file size of 2.97 GB with 10.83 million reads having a maximum read length of 101 nucleotides. The number of contigs generated was 53,854 with maximum and minimum lengths of 10,086 and 200 nucleotides respectively. These trancripts were annotated using BLAST search against the Aracyc, Swiss-Prot, TrEMBL, gene ontology and clusters of orthologous groups (KOG) databases. The genes involved in lipid metabolism were studied and the transcription factors were identified. Sequence similarity studies of Camelina with the other related organisms indicated the close relatedness of Camelina with Arabidopsis. In addition, bioinformatics analysis revealed the presence of a total of 19,379 simple sequence repeats. This is the first report on Camelina sativa L., where the transcriptome of the entire plant, including seedlings, seed, root, leaves and stem was done. Our data established an excellent resource for gene discovery and provide useful information for functional and comparative genomic studies in this promising biofuel crop.

Molecular cloning and characterisation of metallothionein type 2a gene from Jatropha curcas L., a promising biofuel plant.

In the present study, we have cloned a gene encoding JcMT2a protein from Jatropha curcas L., a promising biofuel tree species. Full length sequence of JcMT2a gene was isolated using RACE PCR. Heterologous expression of JcMT2a in Escherichia coli and its purification has shown distinct bands corresponding to the GST and GST-fused JcMT2a protein. Significant tolerance was observed in E. coli cells expressing recombinant GST-JcMT2a for zinc, copper and cadmium metals compared to cells expressing GST alone. JcMT2a also restored Cu and Cd tolerance in the metal sensitive yeast mutants. Quantitative real time PCR showed a significant increase in JcMT2a transcripts with Cu and Cd in the leaf compared to root tissue. Our Scanning electron microscopy and energy dispersive X-ray spectroscopy analysis clearly demonstrates that J. curcas L. could be a potential candidate for phytoremediation to clean heavy metals from the environment, in addition to its non-edible oil seed yields for biodiesel production.

Persulfide formation on mitochondrial cysteine desulfurase: enzyme activation by a eukaryote-specific interacting protein and Fe-S cluster synthesis.

Cysteine desulfurases abstract sulfur from the substrate cysteine, generate a covalent persulfide on the active site cysteine of the enzyme, and then donate the persulfide sulfur to various recipients such as Fe-S clusters. In Saccharomyces cerevisiae, the Nfs1p protein is the only known cysteine desulfurase, and it forms a complex with Isd11p (Nfs1p·Isd11p). Both of these proteins are found primarily in mitochondria and both are essential for cell viability. In the present study we show, using the results of experiments with isolated mitochondria and purified proteins, that Isd11p is required for the cysteine desulfurase activity of Nfs1p. Whereas Nfs1p by itself was inactive, the Nfs1p·Isd11p complex formed persulfide and was active as a cysteine desulfurase. In the absence of Isd11p, Nfs1p was able to bind the substrate cysteine but failed to form a persulfide. Addition of Isd11p allowed Nfs1p with bound substrate to generate a covalent persulfide. We suggest that Isd11p induces an activating conformational change in Nfs1p to bring the bound substrate and the active site cysteine in proximity for persulfide formation. Thus mitochondrial Nfs1p is different from bacterial cysteine desulfurases that are active in the absence of accessory proteins. Isd11p may serve to regulate cysteine desulfurase activity in mitochondria.

Mutation in the Fe-S scaffold protein Isu bypasses frataxin deletion.

Frataxin is a conserved mitochondrial protein deficient in patients with Friedreich's ataxia. Frataxin has been implicated in control of iron homoeostasis and Fe-S cluster assembly. In yeast or human mitochondria, frataxin interacts with components of the Fe-S cluster synthesis machinery, including the cysteine desulfurase Nfs1, accessory protein Isd11 and scaffold protein Isu. In the present paper, we report that a single amino acid substitution (methionine to isoleucine) at position 107 in the mature form of Isu1 restored many deficient functions in Δyfh1 or frataxin-depleted yeast cells. Iron homoeostasis was improved such that soluble/usable mitochondrial iron was increased and accumulation of insoluble/non-usable iron within mitochondria was largely prevented. Cytochromes were returned to normal and haem synthesis was restored. In mitochondria carrying the mutant Isu1 and no frataxin, Fe-S cluster enzyme activities were improved. The efficiency of new Fe-S cluster synthesis in isolated mitochondria was markedly increased compared with frataxin-negative cells, although the response to added iron was minimal. The M107I substitution in the highly conserved Isu scaffold protein is typically found in bacterial orthologues, suggesting that a unique feature of the bacterial Fe-S cluster machinery may be involved. The mechanism by which the mutant Isu bypasses the absence of frataxin remains to be determined, but could be related to direct effects on Fe-S cluster assembly and/or indirect effects on mitochondrial iron availability.

Antimicrobial, anticoagulant and antiplatelet activities of green synthesized silver nanoparticles using Selaginella (Sanjeevini) plant extract.

The recent study deals with the synthesis and characterization of silver nanoparticles bounded to Selaginella bryopteris (Sanjeevini) Plant extract (SPE) as reducing and capping agents. Selaginella bryopteris plant extract silver nanoparticles (SPE@Ag-NPs) was characterized by PXRD, UV-Vis., FESEM, TEM and EDX. The highly stable SPE@Ag-NPs was found promising as antibacterial and antifungal agents when tested against human pathogens S. aureus, E. coli, and A. niger respectively. Furthermore, SPE@Ag-NPs found to show anticoagulant property by enhancing the clotting time of citrated human PRP as well as PPP from the control 160 s to 220 s and 160 s to 284 s respectively. However, SPE@Ag-NPs exhibited mild antiplatelet activity by inhibiting specifically agonist ADP induced platelet aggregation of about 23% at the concentration of 30 µg. Fascinating, SPE@Ag-NPs did not alter the agonist epinephrine-induced platelet function even at the increased dose. Interestingly, SPE@Ag-NPs did not induce edema and hemorrhage in the experimental mice and also did not hydrolyze RBC cells suggesting its nontoxic property. In conclusion, SPE@Ag-NPs was non-toxic and found to exhibit antibacterial, antifungal, anticoagulant and antiplatelet properties. Thus, SPE@Ag-NPs would be a better candidate in the biomedical field especially to treat thrombotic disorders.

Nuclear Factor Kappa B: A Potential Target to Persecute Head and Neck Cancer.

Despite the consistent and significant advancements made in the treatment of head and neck cancer (HNSCC), it remains one of the most devastating cancers globally killing approximately 350,000 people every year. Both clinical and basic research revealed that the transcription factor NF-κB, is constitutively expressed in HNSCC and this persistent expression of NF-κB is the root cause of this disease resulting in cancer cell proliferation, survival, invasion, metastases and poor survival of patients. Activation of NF-κB is pragmatic in most of the premalignant dysplastic lesions indicating it as an early episode in malignant transformation of this disease. Therefore, therapies designed to inhibit or block the activity of NF-κB, would result in downregulation of key cellular processes involved in tumor growth and its dissemination to metastatic sites. In addition, substantial evidences have revealed that NF-κB plays an indispensable role in the development of both chemo and radiation resistance in HNSCC which is identified to be a primary cause for the failure of therapies. This shows the potential of targeting NF- κB in developing therapies against this disease. This review summarises the role of NF-κB in the development of HNSCC and the potential of using NF-κB as a target to develop novel highly effective therapies for this disease.

Specific Targeting of Akt Kinase Isoforms: Taking the Precise Path for Prevention and Treatment of Cancer.

Akt kinase is a serine threonine kinase that exists in three isoforms, located in different chromosomes and has distinct sites of expression which orchestrates diverse cellular processes required for normal functioning of the cell. Though, these Akt isoforms have some overlapping actions, but they also have specific roles and interestingly, sometimes they even perform contrasting functions. There are various alterations such as amplification, overexpression, mutation, etc. associated with these isoforms which have great implications in the development of cancer. Moreover, these alterations also induce chemo and radio resistance in cancer cells that impede the existing treatment modules. Furthermore, many reports have shown their potential as efficient prognostic biomarkers. Although, many studies have discussed the implications of Akt kinase proteins in different cancers but in-depth analysis of isoform- specific involvement is least examined and hence demands more attention. This review discusses the divergent roles of Akt isoforms comprehensively in different cancers and finding their immense prospects as potential targets for cancer prevention and treatment.