Project description:FAM134B is a reticulon-homology domain (RHD)-containing protein that participates in membrane-shaping of the endoplasmic reticulum (ER)8 13. It also functions as a mammalian ER-phagy receptor, mediating the fragmentation and selective degradation of ER sheets in multiple cell types8. However, little is known about the molecular and biophysical mechanisms that control and/or switch between these two FAM134B functions.
Project description:Over the past 15 years, hundreds of previously undiscovered bacterial small open reading frame (sORF)-encoded polypeptides (SEPs) of fewer than fifty amino acids have been identified, and biological functions have been ascribed to an increasing number of SEPs from intergenic regions and small RNAs. However, despite numbering in the dozens in Escherichia coli, and hundreds to thousands in humans, same-strand nested sORFs that overlap protein coding genes in alternative reading frames remain understudied. In order to provide insight into this enigmatic class of unannotated genes, we characterized GndA, a 36-amino acid, heat shock-regulated SEP encoded within the +2 reading frame of the gnd gene in E. coli K-12 MG1655. We show that GndA pulls down components of respiratory complex I (RCI) and is required for proper localization of a RCI subunit during heat shock. At high temperature GndA deletion (ΔGndA) cells exhibit perturbations in cell growth, NADH+/NAD ratio, and expression of a number of genes including several associated with oxidative stress. These findings suggest that GndA may function in maintenance of homeostasis during heat shock. Characterization of GndA therefore supports the nascent but growing consensus that functional, overlapping genes occur in genomes from viruses to humans.
Project description:Rheumatic heart disease (RHD) remains a major source of morbidity and mortality in developing countries. A deeper insight into the pathogenetic mechanisms underlying RHD could provide opportunities for drug repurposing, guide recommendations for secondary penicillin prophylaxis, and/or inform development of near-patient diagnostics. We performed quantitative proteomics using Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectrometry (SWATH-MS) to screen protein expression in 215 African patients with severe RHD, and 230 controls. A machine learning (ML) approach was applied to feature selection among the 366 proteins quantifiable in at least 40% of samples, using the Boruta wrapper algorithm. The case-control differences and contribution to AUC of the ROC for each of the 56 proteins identified by the Boruta algorithm were calculated by Logistic Regression adjusted for age, sex and BMI. Adiponectin, complement component C7 and fibulin-1, a component of heart valve matrix, were each higher in cases when compared with controls. Ficolin-3, a protein with calcium-independent lectin activity that activates the complement pathway, was lower in cases than controls. The top six biomarkers from the Boruta analyses conferred an AUC of 0.90 indicating excellent discriminatory capacity between RHD cases and controls.
