Project description:SARS-CoV-2 proteins orchestrate complex mechanisms that underlie SARS-CoV-2 infection and COVID-19 causing pathogenic processes. Here we have exhaustively defined human proteins in spatial proximity (proximal interaction network) of 27/28 SARS-CoV-2 proteins in human cells by proximity-dependent biotinylation (BioID)-based approach. We report 10,185 high-confidence virus-host PPI involving 2,592 unique cellular targets.
Project description:In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 has been linked to neurodegenerative diseases including Parkinson’s as well as cardiovascular diseases and cancer. Here, we developed nanobodies (Nbs) for proteomics, advanced microscopy and live cell imaging of Drp1. To specifically enrich endogenous Drp1 with interacting proteins for proteomics, we functionalized high-affinity Nbs as capture matrices. Considering the wide range of research applications, the presented Nb toolset will open up new possibilities for advanced functional studies of Drp1 in disease-relevant models.
Project description:Repair of DNA double-strand breaks (DSBs) by non-homologous end-joining is critical for neural development, and brain cells frequently contain somatic genomic variations that might involve DSB intermediates. We now use an unbiased, high-throughput approach to identify genomic regions harboring recurrent DSBs in primary neural stem/progenitor cells (NSPCs). We identify 27 recurrent DSB clusters (RDCs) and, remarkably, all occur within gene bodies. Most of these NSPC RDCs were detected only upon mild, aphidicolin-induced replication stress, providing a nucleotide-resolution view of replication-associated genomic fragile sites. The vast majority of RDCs occur in long, transcribed, and late-replicating genes. Moreover, almost 90% of identified RDC-containing genes are involved in synapse function and/or neural cell adhesion, with a substantial fraction also implicated in tumor suppression and/or mental disorders. Our characterization of NSPC RDCs reveals a basis of gene fragility and suggests potential impacts of DNA breaks on neurodevelopment and neural functions. We performed high-throughput, genome-wide, translocation sequencing (HTGTS) and GRO-seq in primary mouse neural stem/progenitor cells of the indicated genotypes.
Project description:Drosophila Insulator proteins mediate long-range chromosomal interactions. ChIP-seq revealed that binding of insulator proteins to some specific DNA sites was regulated by poly(ADP-ribosyl)ation in S2 cells. Three insulator sites regulated by poly(ADP-ribosyl)ation were used as baits to map their distant interacting sites using 4C assay in control S2 cells. Mapping the chromosomal interactions of three specific insulator binding sites with 4C assay in control S2 cells.
Project description:The treatment of colorectal cancer (CRC) is an unmet medical need in absence of early diagnosis. Here, upon characterizing cancer-specific transposable element-driven transpochimeric gene transcripts (TcGTs) produced by this tumor, we found that expression of the hominid-restricted retrogene POU5F1B through aberrant activation of a primate-specific endogenous retroviral promoter is a strong negative prognostic CRC biomarker. Correlating this observation, we could demonstrate that POU5F1B fosters the proliferation and metastatic potential of CRC cells. We further determined that POU5F1B, in spite of its phylogenetic relationship with the POU5F1/OCT4 transcription factor, is a membrane-enriched protein that associates with protein kinases and known targets or interactors as well as with cytoskeleton-related molecules, and induces intracellular signaling events and the release of trans-acting factors involved in cell growth and cell adhesion. As POU5F1B is an apparently non-essential gene only lowly expressed in normal tissues, and as POU5F1B-containing TcGTs are detected in other tumors besides CRC, our data provide interesting leads for the development of cancer therapies.
Project description:N-terminal proteoforms stem from the same gene but differ at their N-terminus, and most of these are found to be truncated, though some are N-terminally extended caused by ribosomes starting translation from codons in the annotated 5’UTR, and/or carry modified N-termini different from those of the canonical protein. Biological functions of N-terminal proteoforms are emerging, however, it remains unknown to what extend N-terminal proteoforms further expand the functional complexity. To address this in a more global manner, we mapped the interactomes of several pairs of N-terminal proteoforms and their canonical counterparts. For this, we first generated an in-depth catalogue of N-terminal proteoforms in the cytosol of HEK293T cells. From which 20 pairs of canonical protein and N-terminal proteoform(s) were selected. Protein-protein interaction profiling was done with Virotrap. Virotrap was selected as this methods avoids lysis before the isolation of the complexes and allows the detection of weak and cytosolic proteins as well. Our analysis of these pairs revealed that the overlap of the interactomes for both proteoforms is in general high, showing their functional relation. However, for all pairs tested we do report differences as well. We show that N-terminal proteoforms can be engaged in new/different interactions and as well can lose several interactions compared to the canonical protein.
Project description:The human lysosomal polypeptide ABC transporter TAPL (ABC subfamily B member 9, ABCB9) transports 6–59 amino-acids-long polypeptides from the cytosol into lysosomes. The subcellular localization of TAPL depends solely on its N-terminal transmembrane domain TMD0, which lacks conventional targeting sequences. However, the intracellular route and the molecular mechanisms that control TAPL localization remain unclear. Here, we delineated the route of TAPL to lysosomes and investigated the determinants of single trafficking steps. By synchronizing trafficking events by retention using selective hooks (RUSH) assay and visualizing individual intermediate steps through immunostaining and confocal microscopy, we demonstrate that TAPL takes the direct route to lysosomes. We further identified conserved charged residues within TMD0 transmembrane helices that are essential for individual steps of lysosomal targeting. Substitutions of these residues retained TAPL in the endoplasmic reticulum (ER) or Golgi. We also observed that for release from the ER, a salt bridge between Asp-17 and Arg-57 is essential. An interactome analysis revealed that Yip1-interacting factor homolog B, membrane-trafficking protein (YIF1B) interacts with TAPL. We also found that YIF1B is involved in ER-to-Golgi trafficking and interacts with TMD0 of TAPL via its transmembrane domain and that this interaction strongly depends on the newly identified salt bridge within TMD0. These results expand our knowledge about lysosomal trafficking of TAPL and the general function of extra transmembrane domains of ABC transporters.
Project description:This study aimed to evaluate the cost-effective and genome-wide cell-free reduced representation bisulfite sequencing (cfRRBS) method combined with computational deconvolution for effective disease monitoring in patients with esophageal adenocarcinoma (EAC). cfDNA methylation profiling with cfRRBS was performed on 162 blood plasma samples from 33 EAC cancer patients and 28 blood plasma samples from 20 healthy donors. In addition, for reproducibility testing purposes of the method, 9 plasma samples were re-prepped (library was re-made) and re-sequenced once (n=9) or twice (n=1). As a reference for the data deconvolution cfRRBS was performed on 7 EAC tumor tissue (FFPE) samples.