Inhibition of ribonuclease A by nucleoside–dibasic acid conjugates

We report the inhibition of the ribonucleolytic activity of ribonuclease A (RNase A) by nucleoside–dibasic acid conjugates for the first time. Agarose gel and precipitation assays show that the spacer length and the pK_a of the carboxylic group have an important role in the inhibitory capacity. Kinetic experiments indicate a competitive mode of inhibition with inhibition constant (K_i) value of 132 ± 3 μM for Oxa-aT. Docking studies revealed that the carboxylic group of the most active compounds is within hydrogen bonding distance of His-12, Lys-41 and His-119.     

Ticks Associated with Macquarie Island Penguins Carry Arboviruses from Four Genera

Macquarie Island, a small subantarctic island, is home to rockhopper, royal and king penguins, which are often infested with the globally distributed seabird tick, Ixodes uriae. A flavivirus, an orbivirus, a phlebovirus, and a nairovirus were isolated from these ticks and partial sequences obtained. The flavivirus was nearly identical to Gadgets Gully virus, isolated some 30 year previously, illustrating the remarkable genetic stability of this virus. The nearest relative to the orbivirus (for which we propose the name Sandy Bay virus) was the Scottish Broadhaven virus, and provided only the second available sequences from the Great Island orbivirus serogroup. The phlebovirus (for which we propose the name Catch-me-cave virus) and the previously isolated Precarious Point virus were distinct but related, with both showing homology with the Finnish Uukuniemi virus. These penguin viruses provided the second and third available sequences for the Uukuniemi group of phleboviruses. The nairovirus (for which we propose the name Finch Creek virus) was shown to be related to the North American Tillamook virus, the Asian Hazara virus and Nairobi sheep disease virus. Macquarie Island penguins thus harbour arboviruses from at least four of the seven arbovirus-containing genera, with related viruses often found in the northern hemisphere.     

Azadirachta indica (neem): a plant of multiple biological and pharmacological activities

Azadirachta indica, commonly called neem or ‘dogonyaro’ in Nigeria, is a plant that has found varied use in ecological, medicinal and agricultural sectors. Biological and pharmacological activities attributed to different parts and extracts of these plants include antiplasmodial, antitrypanosomal, antioxidant, anticancer, antibacterial, antiviral, larvicidal and fungicidal activities. Others include antiulcer, spermicidal, anthelminthic, antidiabetic, anti-implantation, immunomodulating, molluscicidal, nematicidal, immunocontraceptive, insecticidal, antifeedant and insect repellant effects. But toxicological activities such as allergic, genotoxic, cytogenetic and radiosensitizing effects have also been reported in humans and some economic animals, particularly, aquatic organisms, chicks and goats. Bioassay-guided studies and phytochemical analyses utilizing modern state-of-the-art techniques such as HPLC–MS, GC–MS, NMR and Infra Red spectroscopy have revealed that phytocompounds like azadirachtins, nimocinol, isomeldenin, azadirachtol (a tetranortriterpernoid), 2,3′-dehydrosalanol gedunin, nimbin, nimolicinol, odoratone, azadironolide, isoazadironolide, naheedin and mahmoodin are responsible for the varied biological, pharmacological and toxicological properties observed. In this paper, we review how a developing country like Nigeria can harness the numerous opportunities presented by the multi-biological and multi-pharmacological nature of A. indica to solve some of her myriad problems, including those in the agricultural, health and economic sectors.     

Deuterium-Resistant Algal Cell Line for D Labeling of Heterotrophs Expresses Enhanced Level of Hsp60 in D2O Medium

Fully deuterated components from autotrophic cell lysate are useful materials for labeling of heterotrophs with deuterium. To facilitate the faster production of deuterated algal lysate, we selected a mutant Chlorella strain that grows faster in heavy water than the wild type. The mutant DR-17 was found to have a higher level of Hsp60 and an elevated level of protein synthesis. We previously isolated a deuterium-resistant yeast cell line that was also found to express elevated level of Hsp70 (K. Unno, T. Kishido, M. Morioka, S. Okada, and N. Oku, Biol. Pharm. Bull. 26:799-802, 2003). This suggests that the overexpression of heat shock proteins is required to compensate for the deuterium isotope effect.     

ABI5-binding proteins (AFPs) alter transcription of ABA-induced genes via a variety of interactions with chromatin modifiers

Key message

Overexpression of ABI5/ABF binding proteins (AFPs) results in extreme ABA resistance of seeds via multiple mechanisms repressing ABA response, including interactions with histone deacetylases and the co-repressor TOPLESS.

Abstract

Several ABI5/ABF binding proteins (AFPs) inhibit ABA response, resulting in extreme ABA resistance in transgenic Arabidopsis overexpression lines, but their mechanism of action has remained obscure. By analogy to the related Novel Interactor of JAZ (NINJA) protein, it was suggested that the AFPs interact with the co-repressor TOPLESS to inhibit ABA-regulated gene expression. This study shows that the AFPs that inhibit ABA response have intrinsic repressor activity in a heterologous system, which does not depend on the domain involved in the interaction with TOPLESS. This domain is also not essential for repressing ABA response in transgenic plants, but does contribute to stronger ABA resistance. Additional interactions between some AFPs and histone deacetylase subunits were observed in yeast two-hybrid and bimolecular fluorescence assays, consistent with a more direct mechanism of AFP-mediated repression of gene expression. Chemical inhibition of histone deacetylase activity by trichostatin A suppressed AFP effects on a small fraction of the ABI5-regulated genes tested. Collectively, these results suggest that the AFPs participate in multiple mechanisms modulating ABA response, including both TOPLESS-dependent and -independent chromatin modification.

     

Reconciling food security and bioenergy: priorities for action

Understanding the complex interactions among food security, bioenergy sustainability, and resource management requires a focus on specific contextual problems and opportunities. The United Nations’ 2030 Sustainable Development Goals place a high priority on food and energy security; bioenergy plays an important role in achieving both goals. Effective food security programs begin by clearly defining the problem and asking, ‘What can be done to assist people at high risk?’ Simplistic global analyses, headlines, and cartoons that blame biofuels for food insecurity may reflect good intentions but mislead the public and policymakers because they obscure the main drivers of local food insecurity and ignore opportunities for bioenergy to contribute to solutions. Applying sustainability guidelines to bioenergy will help achieve near‐ and long‐term goals to eradicate hunger. Priorities for achieving successful synergies between bioenergy and food security include the following: (1) clarifying communications with clear and consistent terms, (2) recognizing that food and bioenergy need not compete for land and, instead, should be integrated to improve resource management, (3) investing in technology, rural extension, and innovations to build capacity and infrastructure, (4) promoting stable prices that incentivize local production, (5) adopting flex crops that can provide food along with other products and services to society, and (6) engaging stakeholders to identify and assess specific opportunities for biofuels to improve food security. Systematic monitoring and analysis to support adaptive management and continual improvement are essential elements to build synergies and help society equitably meet growing demands for both food and energy.