A recent publication in Analytical Chemistry by Trenton Peters-Clarke et.al explores the promise of modified oligonucleotides for drug development, with small interfering RNAs (siRNA) and microRNAs gaining traction in the therapeutic market. Mass spectrometry (MS)-based analysis offers many benefits for characterizing modified nucleic acids. Negative electron transfer dissociation (NETD) has proven valuable in sequencing oligonucleotide anions, particularly because it can retain modifications while generating sequence-informative fragments.
In a paper titled Acetyl-CoA Flux Regulates the Proteome and Acetyl-Proteome to Maintain Intracellular Metabolic Crosstalk, Inca Dieterich et al. of Prof Luigi Puglielli’s lab investigated two models of AT-1 dysregulation and altered acetyl-CoA flux: AT-1S113R/+ mice, a model of AT-1 haploin sufficiency, and AT-1 sTg mice, a model of AT-1 overexpression. The animals display distinct metabolic adaptation across intracellular compartments, including reprogramming of lipid metabolism and mitochondria bioenergetics. Our results suggest that AT-1 acts as an important metabolic regulator that maintains acetyl-CoA homeostasis by promoting functional crosstalk between different intracellular organelles.
Capillary zone electrophoresis-tandem mass spectrometry is recognized as an efficient approach for top-down proteomics because of its high-capacity separation and highly sensitive detection of proteoforms. However, the commonly used collision-based methods often don’t provide the extensive fragmentation needed for thorough characterization of proteoforms. Activated ion electron transfer dissociation (AI-ETD), which combines infrared photoactivation with ETD, has shown better performance for proteoform fragmentation than other methods.
Bacterial biofilms are everywhere in nature and play an important role in many clinical, industrial, and ecological settings. Although much is known about the transcriptional regulatory networks that control biofilm formation in model bacteria such as Bacillus subtilis, very little is known about the role of metabolism in this process. To address this important knowledge gap, this study used a time-resolved analysis of the metabolic changes associated with bacterial biofilm development in B. subtilis by combining metabolomic, transcriptomic, and proteomic analyses. This report serves as a unique resource for future studies and will be relevant to future research in microbial physiology and metabolism. The full publication can be found here.
Polo-like kinase 1 has hundreds of substrates and multiple functions that operate within the ∼60 min of mitosis. This paper describes a chemical-genetic system that allows particular substrates to be “toggled” into or out of chemical control using engineered phosphoacceptor selectivity. Kif2b, a known substrate of Plk1 that regulates chromosome alignment was evaluated. Toggling Ser to Thr on Kif2b places these phosphorylation sites under reversible chemical control. Thus, it is demonstrated the ability to chemically control a single substrate by a genetic Ser/Thr toggle.
Specifically, in order to understand how oncogenes remodel isogenic cells, researchers conducted quantitative proteomics on N-linked glycoproteins. Here, researchers observed how a large number of surface proteins were changed in isogenic breast epithelial cell lines to express oncogenes.
In addition to looking at surfaceome data with applied glycoproteoics, researchers also applied activated ion electron transfer dissociation (AI-ETD). Here. researchers found changes to the glycoproteome, as induced by the oncogenes.
Researchers said that these studies could help illustrate how specific oncogenes can remodel both the surfaceome and the glycoproteome in cells. Additionally, this research can help in the production of further cancer antibody drug discovery research.
Two independent conditions are associated with worse outcomes in patients with chronic pulmonary diseases; the retention of a high amount of Co2 (also called “hypercapnia”) and skeletal muscle wasting (also associated with worse outcomes in acute pulmonary disease). Due to the current lack of research on the role of high CO2 levels in regulating skeletal muscle anabolism, researchers sought to investigate the role of high CO2 levels in weakening skeletal muscle protein synthesis in both patients and mice.
Researchers found that locomotor muscles from patients with chronic CO2 retention had decreased ribosomal gene expression in comparison to patients who did not retain CO2 to the same extent. Additionally, researchers found that mice in a high-CO2 environment had downregulated ribosomal biogenesis in their skeletal muscles, as well as decreased protein synthesis.
Evidently, researchers found that there was an impact of high CO2 levels on skeletal muscle synthesis and anabolism. Researchers suggested future studies focusing on ribosomal biogensis and protein synthesis to counteract the impacts of high CO2 on skeletal muscles.
MS-Helios is an easy-to-use command line tool which works to solve the challenge of data analysis and visualization in the face of high-resolution mass spectrometery.
Though high-resolution mass spectrometry can identify hundreds of metabolites and thousands of proteins, this can make data analysis and visualization hard to do.
MS-Helios is a solution, allowing for compact data representation and reduced dimensionality. This tool also allows non-experts and experts alike to generate data and configuration files and publish high-quality, circular plots with Circos.
This software is available for download here. The manuscript for MS-Helios can be viewed here.
Hose et al (2020) researched the genetic basis of aneuploidy tolerance in wild yeast in a recent edition of Elife.
Aneuploidy, or the abnormal chromosome numbers in a cell, is a harmful condition in developmental stages of wild yeast, yet is also common in plant cancers and pathogenic fungi. It is interesting to note that aneuploidy tolerance varies; for instance, researchers found that some wild isolates of baker’s yeast can tolerate chromosome amplification, while laboratory strains cannot.
To study the genetic basis of how well wild yeast can tolerate aneuploidy, researchers mapped the genetic basis to Ssd1, an RNA-binding translational regulator that functions in wild strains but is defective in a laboratory strain “W303.”
Researchers found that aneuploidy tolerance is enabled via a role for Ssd1 in mitochondrial physiology, such as binding and regulating nuclear-encoded mitochondrial mRNAs.
Patients with chronic obstructive pulmonary disease (COPD), a disease that is characterized by obstructed airflow to the lungs and is associated with long-term exposure to cigarette smoke, often also develop skeletal muscle dysfunction. Overall, the comorbidity of COPD and skeletal muscle dysfunction is associated with outcomes such as poor health and mortality.
While some research has suggested that skeletal muscle dysfunction may be the result of COPD-related conditions, such as protein degradation and metabolic disruption, there is still poor understanding on what mechanisms would regulate these processes, as there is little to no research on a validated animal model of pulmonary emphysema. Therefore, Balnis et al (2020) sought to use such a model based on inducible UL-13-driven pulmonary emphysema (IL-13TG) to study the mechanisms of skeletal muscle dysfunction.
Using a transgenic mouse model, researchers found that the skeletal muscles of emphysematous mice are similar to those developed by human patients with COPD. For instance, both groups develop muscular atrophy and have decreased oxygen consumption. Within skeletal muscles, both groups also had downregulated ATP binding and bioenergetics.
Researchers concluded that transgenic animal models of COPD are useful to understand skeletal-muscle dysfunction in humans.
