MatR, a highly conserved, essential mitochondrial protein, functions in the processing and maturation of various pre-RNAs in plant mitochondria, as revealed by

NADP-dependent (Nicotinamide Adénine Dinucléotide Phosphate-dependent) isocitrate dehydrogenases (NADP-ICDH) are metabolic enzymes involved in 2-oxoglutarate biosynthesis, but they also supply cells with NADPH. Different NADP-ICDH genes are found in Arabidopsis among which a single gene encodes for a cytosolic ICDH (cICDH) isoform. Here, we show that cICDH is susceptible to oxidation and that several cysteine (Cys) residues are prone to S-nitrosylation upon nitrosoglutathione (GSNO) treatment. Moreover, we identified a single S-glutathionylated cysteine Cys363 by mass-spectrometry analyses. Modeling analyses suggest that Cys363 is not located in the close proximity of the cICDH active site. In addition, mutation of Cys363 consistently does not modify the activity of cICDH. However, it does affect the sensitivity of the enzyme to GSNO, indicating that S-glutathionylation of Cys363 is involved in the inhibition of cICDH activity upon GSNO treatments. We also show that glutaredoxin are able to rescue the GSNO-dependent inhibition of cICDH activity, suggesting that they act as a deglutathionylation system in vitro. The glutaredoxin system, conversely to the thioredoxin system, is able to remove S-nitrosothiol adducts from cICDH. Finally, NADP-ICDH activities were decreased both in a catalase2 mutant and in mutants affected in thiol reduction systems, suggesting a role of the thiol reduction systems to protect NADP-ICDH activities in planta. In line with our observations in Arabidopsis, we found that the human recombinant NADP-ICDH activity is also sensitive to oxidation in vitro, suggesting that this redox mechanism might be shared by other ICDH isoforms.

We address here organellar genetic regulation and intercompartment genome coordination. We developed earlier a strategy relying on a tRNA-like shuttle to mediate import of nuclear transgene-encoded custom RNAs into mitochondria in plants. In the present work, we used this strategy to drive trans-cleaving hammerhead ribozymes into the organelles, to knock down specific mitochondrial RNAs and analyze the regulatory impact. In a similar approach, the tRNA mimic was used to import into mitochondria in Arabidopsis thaliana the orf77, an RNA associated with cytoplasmic male sterility in maize and possessing sequence identities with the atp9 mitochondrial RNA. In both cases, inducible expression of the transgenes allowed to characterise early regulation and signaling responses triggered by these respective manipulations of the organellar transcriptome. The results imply that the mitochondrial transcriptome is tightly controlled by a “buffering” mechanism at the early and intermediate stages of plant development, a control that is released at later stages. On the other hand, high throughput analyses showed that knocking down a specific mitochondrial mRNA triggered a retrograde signaling and an anterograde nuclear transcriptome response involving a series of transcription factor genes and small RNAs. Our results strongly support transcriptome coordination mechanisms within the organelles and between the organelles and the nucleus.

Recent outbreak of Coronavirus Disease 2019 (COVID-19) caused by a novel ‘SARS-CoV-2’ virus resulted public health emergencies across the world. An effective vaccine to cure this virus is not yet available, thus requires concerted efforts at various scales. In this study, we employed Computer Aided Drug Design (CADD) based approach to identify the drug-like compounds - inhibiting the replication of main protease (M^pro) of SARS-CoV-2. Our database search using online tool “ZINC pharmer” retrieved ~1500 compounds based on pharmacophore features. Lipinski’s rule was applied to further evaluate the drug-like compounds, followed by molecular docking-based screening, and the selection of screening ligand complex with M^pro based on S-score (higher than reference inhibitor) and root-mean-square deviation (RMSD) value (less than reference inhibitor) using Molecular Operating Environment (MOE) system. Resultantly, ~200 compounds were identified having strong interaction with M^pro of SARS-CoV-2. After evaluating their binding energy using the MOE LigX algorithm, three compounds (ZINC20291569, ZINC90403206, ZINC95480156) were identified that showed highest binding energy with M^pro of SARS-CoV-2 and strong inhibition effect than the reference inhibitor. It is suggested that these candidate “drug-like compounds” have greater potential to stop the replication of SARS-CoV-2, hence might lead to the cure of COVID-19.

Background: Sheath or gelling saliva, secreted during feeding by aphids, is a hard material that supports the piercing mouthparts and remains in the plant after feeding. Solidification or gelling of the saliva might be due to the composition of amino acids in the constituent proteins, many of which probably interact with plant defenses. Objective: The complete complement of proteins in the gelling saliva are still unknown, although one sheath protein (SHP) has previously been identified as a potential candidate protein to control aphid feeding, but its structure and its physiochemical role remains obscure. The current study provides structural information and biochemical properties of the aphid sheath protein. Methods: Sheath protein encoding gene was amplified from cDNA of the pea aphid (Acyrthosiphon pisum) through PCR using specific gene primers. Sequence was in silico characterized by using EXPASY, Berkeley Drosophila Genome Project (BDGP) Neural Network Promoter Prediction, BioEdit, Mega7, ProtParam, Phyre server, 3D LigandSite SMART, MEME and GSDS programs, available online. Results: BLASTp results showed that the sequenced gene was identical (100%) to the sequence from Acyrthosiphon pisum, with 87% identity to Metpolophium dirhodum and 84% identity to Sitobion avenae. Phylogenetically monocot feeders such as M. dirhodum and S. avenae are in a sister taxa to dicot feeders. In silico analysis of the sequence revealed that sheath protein has a molecular weight of 144 kDa and 50% of the protein is composed of only six amino acids, i.e., threonine, serine, aspartic acid, glutamic acid, isoleucine and tyrosine. The computed IP value revealed that sheath protein is acidic in nature. Ligand binding sites for sheath protein were predicted on residues 1123 and 1125 (isoleucine and glutamine, respectively). Metallic heterogens are also present in sheath protein that are iron, zinc and magnesium, respectively. Conclusion: It is conceivable that variation in the salivary gene sequences may reveal important biological information of relevance to the insect-plant interaction. Further exploration of insect salivary proteins, their composition and structure will provide powerful information, especially when these proteins are interacting with plant proteins, and specific information about the sheath protein, which is interacting with plants at a molecular/cellular level, will be important to progress strategies aimed specifically against sucking pests such as aphids.

Coronavirus that is also known as COVID-19 disease is produced by SARSCoV-2. This causative agent is highly contagious and can cause potentially fatal pneumonia worldwide with serious public health concerns. In the beginning among infected individuals, most of them were those who were mainly shown to the wet animal market in a big city of China known as Wuhan. So, it was suggested that this was almost certainly the zoonotic source of COVID-19illness. The transitional source of origin and their mode of transmission to humans were not known obviously. Conversely, from human to human rapidly transformation have been confirmed generally. Currently, there is no availability of FDA approved clinically antiviral drugs and/or vaccines to be used against the COVID-19. Afterward, SARS-CoV and MERS-CoV, the occurrence of SARS-CoV-2 has been manifested as the third sketch of an enormously pathogenic coronavirus into human population globally. In this review, we provide a brief overview of the history of COVID-19 in Pakistan up-to 18th weeks after beginning, current situation, epidemiology, and its impact on the human population. Moreover, we focused on physiological variation during the incubation period, genome analysis of SARS-CoV2, supportive treatment approaches, and safety measures in the Pakistani population, which may be supportive for combating the risk of COVID-19 epidemic. We also reviewed the future approaches for the development of therapeutic interventions and vaccines to cope with the COVID-19 epidemic.