Project description:Attachment of the ubiquitin (UB) peptide to proteins via the E1-E2-E3 enzymatic machinery regulates diverse biological pathways, yet identification of the substrates of E3 UB ligases remains a challenge. We overcame this challenge by constructing an “orthogonal UB transfer (OUT) cascade with yeast E3 Rsp5 to enable the exclusive delivery of an engineered UB (xUB) to Rsp5 and its substrate proteins. The OUT screen uncovered new Rsp5 substrates in yeast, such as Pal1 and Pal2 that are partners of endocytic protein Ede1, and chaperones Hsp70-Ssb, Hsp82, and Hsp104 that counteract protein misfolding and control self-perpetuating amyloid aggregates (prions), resembling those involved in human amyloid diseases. We showed that prion formation and effect of Hsp104 on prion propagation are modulated by Rsp5. Overall, our work demonstrates the capacity of OUT to deconvolute the complex E3-substrate relationships in crucial biological processes such as endocytosis and protein assembly disorders through protein ubiquitination.
Project description:The RNA-binding protein Argonaute 2 (AGO2) is a key effector of RNA-silencing pathways It exerts a pivotal role in microRNA maturation and activity, and can modulate chromatin remodeling, transcriptional gene regulation and RNA splicing. The Estrogen Receptor beta (ERβ) is endowed with oncosuppressive activities, antagonizing hormone-induced carcinogenesis and inhibiting growth and oncogenic functions in luminal-like breast cancers (BCs), where its expression correlates with a better prognosis of the disease. Applying interaction proteomics coupled to mass spectrometry (MS) to characterize nuclear factors cooperating with ERβ in gene regulation, we identify AGO2 as a novel partner of ERβ in human BC cells. ERβ-AGO2 association was confirmed in vitro and in vivo both in the nucleus and in cytoplasm and is shown to be RNA-mediated. ChIP-Seq demonstrates AGO2 association to a large number of ERβ binding sites, and total and nascent RNA-Seq in ERβ+ vs ERβ- cells, and before and after AGO2 knock-down in ERβ+ cells, reveals a widespread involvement of this factor in ERβ-mediated regulation of gene transcription rate and RNA splicing. Moreover, isolation and sequencing by RIP-Seq of ERβ-associated long and small RNAs in the cytoplasm suggests involvement of the nuclear receptor in RISC loading, indicating that it may able to control directly also mRNA translation efficiency and stability.These results demonstrate that AGO2 can act as a pleiotropic functional partner of ERβ, indicating that both factors are endowed with multiple roles in the control of key cellular functions
Project description:To examine the protein composition of germ granules subcompartments of C. elegans, while ensuring their physiological integrity, we utilized TurboID-based proximity biotin labeling techniques to idedtify the protein components of P granules, Z granules and Mutator foci in the germline of C.elegans.
Project description:The RNA-binding protein Trim71/Lin41 is a phylogenetically conserved developmental regulator that functions in mammalian stem cell reprogramming, brain development and cancer. Trim71 recognizes target mRNAs through hairpin motifs and silences them through molecular mechanisms that await identification. Deposited data are mass spectrometry data from immunoprecipitation experiments with endogenously tagged Trim71, Ago2, and Tnrc6a. Experiments are carried out in mouse embryonic stem cells (mESCs) and uncover reciprocal interactions of Trim71, Ago2, and Tnrc6a. Trim71 protein interactions are largely independent of Ago2 levels, but strongly depend on the presence of RNA. A second set of experiments is mass spectrometry data from immunoprecipitation experiments in mESCs overexpressing a tagged peptide derived from Homo sapiens TNRC6B (‘FLAG-HA::T6BWT::Cherry’), that is known to block the Tnrc6-Ago2 interaction. We show that a wild-type version strongly binds Ago1 and Ago2, but not Trim71, while a mutant version binds neither Ago1, 2, nor Trim71.
Project description:The RNA-binding protein Trim71/Lin41 is a phylogenetically conserved developmental regulator that functions in mammalian stem cell reprogramming, brain development and cancer. Trim71 recognizes target mRNAs through hairpin motifs and silences them through molecular mechanisms that await identification. Deposited data are mass spectrometry data from immunoprecipitation experiments with endogenously tagged Tnrc6a. Experiments are carried out in mouse embryonic stem cells (mESCs) in the presence and absence of RNase A.
Project description:Cerebral organoids â three-dimensional cultures of human cerebral tissue derived from pluripotent stem cells â have emerged as models of human cortical development. However, the extent to which in vitro organoid systems recapitulate neural progenitor cell proliferation and neuronal differentiation programs observed in vivo remains unclear. Here we use single-cell RNA sequencing (scRNA-seq) to dissect and compare cell composition and progenitor-to-neuron lineage relationships in human cerebral organoids and fetal neocortex. Covariation network analysis using the fetal neocortex data reveals known and novel interactions among genes central to neural progenitor proliferation and neuronal differentiation. In the organoid, we detect diverse progenitors and differentiated cell types of neuronal and mesenchymal lineages, and identify cells that derived from regions resembling the fetal neocortex. We find that these organoid cortical cells use gene expression programs remarkably similar to those of the fetal tissue in order to organize into cerebral cortex-like regions. Our comparison of in vivo and in vitro cortical single cell transcriptomes illuminates the genetic features underlying human cortical development that can be studied in organoid cultures. 734 single-cell transcriptomes from human fetal neocortex or human cerebral organoids from multiple time points were analyzed in this study. All single cell samples were processed on the microfluidic Fluidigm C1 platform and contain 92 external RNA spike-ins. Fetal neocortex data were generated at 12 weeks post conception (chip 1: 81 cells; chip 2: 83 cells) and 13 weeks post conception (62 cells). Cerebral organoid data were generated from dissociated whole organoids derived from induced pluripotent stem cell line 409B2 (iPSC 409B2) at 33 days (40 cells), 35 days (68 cells), 37 days (71 cells), 41 days (74 cells), and 65 days (80 cells) after the start of embryoid body culture. Cerebral organoid data were also generated from microdissected cortical-like regions from H9 embryonic stem cell derived organoids at 53 days (region 1, 48 cells; region 2, 48 cells) or from iPSC 409B2 organoids at 58 days (region 3, 43 cells; region 4, 36 cells).
Project description:The canonical NF-κB pathway is active in 70% of all pancreatic cancer cases and NF-κB Essential Modulator (NEMO) is essential for the activation of this pathway. In our study, we used KC mice, which express the oncogenic KRAS and develop precancerous lesions termed Pancreatic Intraepithelial Neoplasias (PanINs), and KNeC mice, which express the oncogenic KRAS and have NEMO deleted in their pancreatic cells. These mice were injected with cerulein to promote the development of pancreatitis (cerulein dosage= 50μg/kg). Cerulein was injected at 8 hourly intervals for 2 days in total. The first injection day was when mice reached their sixth week of age and the second injection day was 3 days after the first injection day. Both KC and KNeC mice developed PanINs. At the age of 10 months, pancreata of KC and KNeC mice were analyzed. Using laser capture microdissection, PanINs from both groups were excised and their transcriptome was analyzed though RNA-seq.
Project description:Activin/Nodal signalling is necessary to maintain pluripotency of human Embryonic Stem Cells (hESCs) and to induce their differentiation towards endoderm. However, the mechanisms by which Activin/Nodal signalling achieves these opposite functions remain unclear. To unravel these mechanisms, we examined the transcriptional network controlled in hESCs by Smad2 and Smad3 which represent the direct effectors of Activin/Nodal signalling. These analyses reveal that Smad2/3 participate in the control of the core transcriptional network characterising pluripotency which includes Oct-4, Nanog, FoxD3, Dppa4, Tert, Myc and UTF-1. In addition, similar experiments performed on endoderm cells confirm that a broad part of the transcriptional network directing differentiation is downstream of Smad2/3. Therefore, Activin/Nodal signalling appears to control divergent transcriptional networks in hESCs and in endoderm. Importantly, we observed an overlap between the transcriptional network downstream of Nanog and Smad2/3 in hESCs while functional studies showed that both factors cooperate to control the expression of pluripotency genes. Therefore, the effect of Activin/Nodal signalling on pluripotency and differentiation could be dictated by tissue specific Smad2/3 partners such as Nanog, explaining the mechanisms by which signalling pathways can orchestrate divergent cell fate decisions. Identification of Smad2/3 binding sites in pluripotent hESCs. 5 ChIP-Seq samples including 1 input control sample and 4 ChIP samples (two conditions x two replicates).
Project description:Obesity and its consequences on cardiometabolic health have been associated to low-grade inflammation. The most diverse source of dietary anti-inflammatory compounds is polyphenols and especially anthocyanins, which are major polyphenols in bilberries (Vaccinium myrtillus). We investigated the effects of a bilberry-rich diet on glucose and lipid metabolism, inflammation and gene expression profile in peripheral blood mononuclear cells (PBMCs) in subjects with overweight and other features of the metabolic syndrome. The study was a randomized, controlled clinical intervention using 2-arm parallel group design. The participants in the bilberry group (BB, n = 15) consumed bilberries or berry products equivalent of 400 g fresh bilberries daily for 8 weeks, while the participants in the control group (C, n = 12) were asked to maintain their habitual diet. The microarray profiling was done from 3 subjects in the BB group and further QPCR expression analyses from all subjects in both groups at the start and end of the intervention (weeks 0 and 8). From 50 differentially expressed transcripts (P<0.005), five candidate genes; WDSUB1, COX7B, RGS18, DAPP1 and TICAM1, were randomly selected for QPCR analyses from PBMCs in both groups. To further explore the interplay of dietary change and activated pathways in PBMCs, 11 additional genes were selected for QPCR. The selected transcripts were from the LPB, RIPK-1, Ly96 (MD2), CD19, MMD, TNFRSF12A, CD72, CCR2, IL17RC, IL17R and MAP3K7IP2 genes. Our results indicate that regular bilberry intake may reduce endotoxemia and chronic inflammation, the latter especially by directing the immunity away from overactive innate cell mediated responsiveness. Bilberry consumption may decrease cardiovascular and metabolic risk in the long term. The microarray profiling was done in PBMCs from 3 subjects in BB group and further QPCR expression analyses in PBMCs from 15 subjects in the BB group and 12 subjects in the C group. For QPCR expression analyses; Time point (biological replicate): 0 wk: baseline PBMCs1 - 15, baseline PBMCc1- 12 Time point (biological replicate): 8 wk: bilberry PBMCs1 - 15, bilberry PBMCc1 - 12 Non-normalized data with triplicate samples (technical replicate) of each bilogical replicates (replicate1-3)
Project description:we treated MFE cell (WT and HDAC6 KO) with different stresses, incluing MG132, CytoD and IAV infection, then use home-made HDAC6 antibody to capture HDAC6 and coimmunoprecipitate its interacting proteins.