A molecular perspective on terpene variation in Australian Myrtaceae

The terpenoid-dominated essential oils in Australian Myrtaceae mediate many ecological interactions and are important industrially. Of all the significant essential oil-producing families, Myrtaceae is the only one for which there is no molecular information on terpene biosynthesis. Here we summarise available knowledge on terpene biosynthesis and its relevance to the Myrtaceae to provide a foundation for ecological and genetic studies of chemical diversity. There are several steps in the terpene biosynthesis pathway that have potential for influencing the oil yield, profile and composition of leaf oils in Myrtaceae. The biochemical steps that influence oil yield in Myrtaceae probably occur in the steps of the pathway leading up to the synthesis of the terpene backbone. Qualitative differences in oil profiles are more likely to be due to variation in terpene synthases and terpene-modifying enzymes. Most of the information on molecular variation in terpene biosynthesis is based on the analysis of artificially derived mutants but Australian Myrtaceae can provide examples of the same mechanisms in an ecological context

Identification of an Antiviral Signaling Variant Demonstrates Immune Regulation Through Alternative Translation

Innate immune signaling pathways initiate host defenses against viral pathogens. Receptors specific for viral nucleic acids activate these pathways culminating in cell-to-cell communication and/or cell death. In mammals, this cell- to-cell communication is achieved through the production of interferons and pro- inflammatory cytokines, which activate antiviral defenses in uninfected neighboring cells and instruct adaptive immune responses. The production of these signaling molecules is essential for the defense against viral infection, but must also be tightly regulated to prevent unnecessary inflammation. As an antiviral defense, cell death is also an effective mechanism to limit viral replication and spread but comes with the cost of tissue damage and inflammation. Therefore, regulating these antiviral responses is critical for controlling the spread of infection as well as preventing unnecessary pathologies related to excessive signaling. Hundreds of genes are involved in controlling these immune responses and a wide variety of mechanisms are utilized to regulate them. One mechanism to regulate gene function is the generation of protein variants through alternative translation. While polycistronic transcripts are a common feature of bacterial and viral gene expression, the process of alternative translation as a means to regulate gene function is not a feature generally attributed to mammalian mRNA. This dissertation describes a novel regulator of antiviral signaling that is generated through alternative translation. Expression of the transcript encoding the antiviral adaptor protein, MAVS, results in the production of two proteins: the full-length MAVS adaptor and a truncated variant, miniMAVS. Production of these proteins is in part regulated by cis-acting elements that control translation initiation. Production of miniMAVS regulates antiviral signaling by limiting interferon production induced by full-length MAVS, whereas both MAVS variants positively regulate cell death. To identify other examples of alternative translation in mammalian cells a genome-wide ribosomal profiling technique was used to generate a candidate list of antiviral truncation variants. This dissertation therefore demonstrates that protein variants generated through alternative translation of polycistronic mRNAs can be an effective mechanism for immune regulation and may be more common than previously understood

Studies of Complexes of the Transition Metals IV. Cobalt Complex with Dithiomalonate

The cobalt (II) ion and the dithiolmalonate ion form a complex which is reasonably stable in aqueous solution and highly colored. Studies were conducted by means of spectrophotometric methods in the visible region. The composition of the complex and the overall formation constant were determined using the method of continuous variation of Job and successive dilutions of stoichiometric proportions of the ligand and metal. All measurements were made at room temperature with the solutions kept at a constant ionic strength of 0.1. The results indicate the composition of the complex to be that of three moles of ligand to one mole of cobalt. The formation constant obtained is lower than that of the cobalt dithioloxalate complex, indicating that the six membered ring is less stable than a similar five membered ring

Separating Instability from Aggregation Propensity in γS-Crystallin Variants

AbstractMolecular dynamics (MD) simulations, circular dichroism (CD), and dynamic light scattering (DLS) measurements were used to investigate the aggregation propensity of the eye-lens protein γS-crystallin. The wild-type protein was investigated along with the cataract-related G18V variant and the symmetry-related G106V variant. The MD simulations suggest that local sequence differences result in dramatic differences in dynamics and hydration between these two apparently similar point mutations. This finding is supported by the experimental measurements, which show that although both variants appear to be mostly folded at room temperature, both display increased aggregation propensity. Although the disease-related G18V variant is not the most strongly destabilized, it aggregates more readily than either the wild-type or the G106V variant. These results indicate that γS-crystallin provides an excellent model system for investigating the role of dynamics and hydration in aggregation by locally unfolded proteins

The Lantern Vol. 2, No. 1, December 1933

• Petition • Keep it Burning! • Jes\u27 Before Christmas • Noel: Translation from Theophile Gautier • A Young Jew Meets Jesus • Book Review: Little Man, What Now? • Book Review: Thunder and Dawn • Continuity • La Veille de Noel (Reflexions d\u27un Provincial) • Noel Sceptique par Jules LaFargue • Horizon • Winter Night • Linoleum Cutshttps://digitalcommons.ursinus.edu/lantern/1001/thumbnail.jp