Tropheryma whipplei proteome - Analyses of new genomic, transcriptomic or proteomic data commonly result in trashing many unidentified data escaping the ‘canonical’ DNA-RNA-protein scheme
ABSTRACT: Analyses of new genomic, transcriptomic or proteomic data commonly result in trashing many unidentified data escaping the ‘canonical’ DNA-RNA-protein scheme. Testing systematic exchanges of nucleotides over long stretches produces inversed RNA pieces (here named “swinger” RNA) differing from their template DNA. These may explain some trashed data. Here analyses of genomic, transcriptomic and proteomic data of the pathogenic Tropheryma whipplei according to canonical genomic, transcriptomic and translational 'rules' resulted in trashing 58.9% of DNA, 37.7% RNA and about 85% of mass spectra (corresponding to peptides). In the trash, we found numerous DNA/RNA fragments compatible with “swinger” polymerization. Genomic sequences covered by «swinger» DNA and RNA are 3X more frequent than expected by chance and explained 12.4 and 20.8% of the rejected DNA and RNA sequences, respectively. As for peptides, several match with “swinger” RNAs, including some chimera, translated from both regular, and «swinger» transcripts, notably for ribosomal RNAs. Congruence of DNA, RNA and peptides resulting from the same swinging process suggest that systematic nucleotide exchanges increase coding potential, and may add to evolutionary diversification of bacterial populations.
Project description:The eukaryotic flagellum is a prominent organelle with conserved structure and diverse functions. Here we present a proteomic study of the flagella and pellicle of Euglena gracilis, a photosynthetic and highly adaptable protist, which employs its flagella for both locomotion and environmental sensing. The biochemically distinct flagella of this euglenozoan yields 1,684 protein groups, which challenges previous estimates on the protein composition of motile flagella across the eukaryotes.
Project description:Euglena gracilis is regarded as a flexible and adaptable free-living protist of considerable biotechnological interest. We carried out proteomic analysis of the E. gracilis purified chloroplast and mitochondrion. These data provide a new level of insight into functions and unique characteristics of these organelles and reveals the manner, in which these differ from its counterparts in other organisms.
Project description:During DNA replication, nucleosomes are rapidly assembled on newly synthesized DNA to restore chromatin organization. Asf1, a key histone H3-H4 chaperone required for this process, is phosphorylated by Tousled-Like Kinases (TLKs). Here, we identify TLK phosphorylation sites by mass spectrometry and dissect how phosphorylation impacts on human Asf1 function. The divergent C-terminal tail of Asf1a is phosphorylated at several sites and this is required for timely progression through S phase. Consistent with this, biochemical analysis of wild-type and phospho-mimetic Asf1a shows that phosphorylation enhances binding to histones and the downstream chaperones CAF-1 and HIRA. Moreover, we find that TLK phosphorylation of Asf1a is induced in cells experiencing deficiency of new histones and that TLK interaction with Asf1a involves its histone-binding pocket. We thus propose that TLK signaling promotes histone supply in S phase by targeting histone-free Asf1 and stimulating its ability to shuttle histones to sites of chromatin assembly.
Project description:The nuclear lamina has multiple functions, including maintaining nuclear structural integrity and differential gene expression. Correct spatial and temporal lamina assembly is essential to meet these and other roles. Recently, it emerged that multiple lamina systems exist that are likely products of independent origins, while all these systems share remarkably analogous functions. Several lamina proteins are known in trypanosomes, two of which, NUP-1 and NUP-2, are essential, coiled-coil proteins with a molecular mass 450 and 250 kDa, respectively. Sequence analysis indicates distinct quaternary structures when compared to the ~60 kDa lamin proteins of multiple lineages, including metazoa. To uncover organisational principles of the trypanosome lamina we generated NUP-1 deletion mutants (N=N-terminal domain; C= C-terminal domain; NC: fusion of the N- and C-terminal domain with entire repeat region deletedd))designed to identify domains of NUP-1 responsible for oligomerisation. We find that both N- and C-termini act as interaction domains and disruption of these interactions impacts additional components of the lamina, the nuclear envelope and nucleoporin TbNup98. By contrast there is remarkably little impact on transcription, crucially including silencing of telomeric variant surface glycoprotein genes. These data indicate that both terminal domains of NUP-1 have roles in assembling the trypanosome lamina and suggest an architecture distinct to the lamin system is based on a ‘hub and spoke’ configuration.
Project description:Conversion of monocytes to osteoclasts is a unique terminal differentiation process within the hematopoietic system involving differentiation and massive cell fusion. Here we focused on DNA methylation changes during osteoclastogenesis. Hypermethylation and hypomethylation changes took place in several thousand genes, including all relevant functional categories in osteoclast differentiation and function. Comparison between the DNA methylation levels of CD14+ monocytes and derived osteoclast from 3 female donors. Bisulphite converted DNA from the 6 samples was hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:Autoimmune rheumatic diseases are complex disorders, whose etiopathology is attributed to a crosstalk between genetic predisposition and environmental factors. Both variants of autoimmune susceptibility genes and environment are involved in the generation of aberrant epigenetic profiles in a cell-specific manner, which ultimately result in dysregulation of expression. Furthermore, changes in miRNA expression profiles also cause gene dysregulation associated with aberrant phenotypes. In rheumatoid arthritis, several cell types are involved in the destruction of the joints, synovial fibroblasts being among the most important. In this study we performed DNA methylation and miRNA expression screening of a set of rheumatoid arthritis synovial fibroblasts and compared the results with those obtained from osteoarthritis patients with a normal phenotype. DNA methylation screening allowed us to identify changes in novel key target genes like IL6R, CAPN8 and DPP4, as well as several HOX genes. A significant proportion of genes undergoing DNA methylation changes were inversely correlated with expression. miRNA screening revealed the existence of subsets of miRNAs that underwent changes in expression. Integrated analysis highlighted sets of miRNAs that are controlled by DNA methylation, and genes that are regulated by DNA methylation and are targeted by miRNAs with a potential use as clinical markers. Our study enabled the identification of novel dysregulated targets in rheumatoid arthritis synovial fibroblasts and generated a new workflow for the integrated analysis of miRNA and epigenetic control. Comparison between the DNA methylation levels of synovial fibroblasts isolated from 6 Osteoarthritis and 6 Rheumatoid arthritis patients isolated from synovial tissues at the time of joint replacement. Bisulphite converted DNA from the 12 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:In endolysosomal networks, two hetero-hexameric tethers called HOPS and CORVET are found widely throughout eukaryotes. The ciliate Tetrahymena thermophila is a unicellular organism with elaborate endolysosomal pathways. Curiously, Tetrahymena and related protozoa have lost HOPS. Tetrahymena encodes multiple paralogs of most CORVET subunits, assembled into six distinct hexameric complexes, including a distinct Vps8 subunit. Here we analyze the composition of these complexes immunoisolated by affinity capture using the Vps8-FLAG paralogs as bait.
Project description:Addressing the functionality of predicted genes remains an enormous challenge in the post-genomic era. A prime example of genes lacking functional assignments are the poorly conserved, early expressed genes of lytic bacteriophages, whose products are involved in the subversion of the host metabolism. In this study, we focused on the composition of important macromolecular complexes of Pseudomonas aeruginosa involved in transcription, DNA replication, fatty acid biosynthesis, RNA regulation, energy metabolism and cell division, during infection with members of seven distinct clades of lytic phages. Using affinity purifications of these host protein complexes coupled to mass spectrometric analyses, 37 host complex-associated phage proteins could be identified. Importantly, eight of these show an inhibitory effect on bacterial growth upon episomal expression, suggesting that these phage proteins are potentially involved in hijacking the host complexes. Using complementary protein-protein interaction assays, we further mapped the inhibitory interaction of gp12 of phage 14-1 to the α subunit of the RNA polymerase. Together, our data demonstrate the powerful use of interactomics to unravel the biological role of hypothetical phage proteins, which constitute an enormous untapped source of novel antibacterial proteins.
Project description:Large amounts of carbon sequestered in permafrost are becoming available for microbial degradation. We investigated 1,529 microbial metagenome-assembled genomes recovered from our site to understand carbon processing in this environment. Metabolic reconstruction, supported by metatranscriptomic and metaproteomic data, revealed key populations involved in organic matter degradation, including bacteria encoding a pathway for xylose degradation only previously identified in fungi.
Project description:We sequenced and assembled a detailed transcriptome and draft genome for E. gracilis Z1. To improve annotation and investigate gene expression in E. gracilis, where most transcripts are also trans-spliced, we conducted comparative proteomic and transcriptomic analysis between light and dark-adapted E. gracilis. The analysis revealed that alterations to protein abundance are controlled post-transcriptionally, surprisingly similar to trypanosomatids.