Project description:Crosslinking mass spectrometry was used to identify the site of dimerization in the RING domain of ZNRF3. The two proteins, ZNRF3 and RNF43 have a key role in regulating the number of Frizzled (FZD) receptor on cells and their inactivation causes cancer. This is because they are RING E3 ligases that promote the ubiquitylation and internalisation of FZD, thereby turning off WNT signalling. Here we identify the key determinants of ubiquitin transfer by ZNRF3 and RNF43 and report the structure of the RING domain from ZNRF3. Our data indicate that the RING domain is monomeric, and that RING dimerization is not required for its ubiquitin ligase activity. However, the ectodomain of ZNRF3 forms dimers and our data supports a model where the cytoplasmic domains self-associate in cells even though RING dimerization is not required for activity.
Project description:To investigate response or resistance to endocrine therapy, mice with targeted over-expression of Esr1 or CYP19A1 to mammary epithelial cells were employed, representing two direct pathophysiological interventions in estrogen pathway signaling. Both Esr1 and CYP19A1 over-expressing mice responded to letrozole with reduced HAN prevalence and decreased mammary epithelial cell proliferation. CYP19A1 over-expressing mice were tamoxifen-sensitive but Esr1 over-expressing mice were tamoxifen-resistant. Increased ER expression occurred with tamoxifen resistance but no consistent changes in progesterone receptor, pSTAT3, pSTAT5, cyclin D1 or cyclin E levels in association with response or resistance was found. RNA-seq was employed to seek a transcriptome predictive of tamoxifen resistance using these models and a second tamoxifen-resistant model, BRCA1 deficient/Trp53 haploinsufficient mice. Sixty-eight genes associated with immune system processing were upregulated in tamoxifen-resistant Esr1 and Brca1 deficient mice whereas genes related to aromatic compound metabolic process were upregulated in tamoxifen-sensitive CYP19A1 mice. Interferon Regulatory Factor 7 was identified as a key transcription factor regulating these 68 immune processing genes. Two loci encoding novel transcripts with high homology to human IGLL1 were uniquely upregulated in the tamoxifen-resistant models. Letrozole proved to be a successful alternative to tamoxifen. Further study of transcriptional changes associated with tamoxifen resistance including immune-related genes could expand our mechanistic understanding and lead to biomarkers predictive of escape or response to endocrine therapies. Single- and paired-end mRNA-seq with WT, Esr1 over-expressing (CERM, tetracycline-operator(tet-op)-Esr1MMTV-rtTA), CYP19A1 over-expressing (AROM, tet-op-CYP19A1MMTV-rtTA) and Brca1 KO (BRCA, Brca1fl11/fl11/MMTV-Cre/p53+/- ) mice
Project description:In this study, we report a patient with a novel homozygous variant in HYOU1 (NM_001130991.3:c.1331C>A, p.Pro444His), who was born to related parents and presented with combined immunodeficiency, failure to thrive, and hypoglycemia. We undertook a multiomics analysis combining transcriptomics, proteomics, and single cell RNA sequencing analyses, demonstrating a drastic reduction in B cell count and hypogranulation of neutrophils in conformity with the findings of immunophenotyping. Additionally, we showed that despite the HYOU1 transcript being expressed and stable, the patient has HYOU1 deficiency at the protein level. Moreover, single cell RNA sequencing of bone marrow revealed that the B cell differentiation process is prematurely arrested at pre-pro B cell stage. The present dataset corresponds to the single-cell RNAseq performed on unsorted cells obtained from peripheral blood and bone marrow samples of the patient and healthy controls (three biological replicates for the patient and four controls)
Project description:Intracellular calcium levels are finely tuned through intricate actions of a number of channels and transporters, including those at key endocellular stores, e.g. endoplasmic reticulum (ER), lysosomes, and mitochondria. Along with the highly homologous genes Inositol 1,4,5-trisphosphate (IP3) receptor type 1 (ITPR1) and 2 (ITPR2), ITPR3 encodes the IP3 receptor (IP3R), a key player in intracellular calcium release in animals. Here we report the first cases of ITPR3 defects in man leading to a primarily dysimmune phenotype. In four unrelated patients of diverse ethnicity, and suffering from a complex immunodeficiency syndrome, we report the same de novo pathogenic variant - c.7570C>T; p.Arg2524Cys - in ITPR3. Clinically, recurrent severe infectious episodes of viral and bacterial origins, features of ectodermal dysplasia and that of Charcot-Marie-Tooth disease were paramount. The identified variant does not affect gene transcription, yet it was structurally predicted and biologically proven to disrupt proper protein folding and function in vivo. This eventually leads to defective Calcium flux in patient cells, dysregulation of mitochondrial function and a broad dysimmune phenotype characterized primarily by a profound CD4 T cell lymphopenia associated with quasi absence of naïve CD4 and CD8 cells, itself mirrored by an increase in cognate memory cells. The Calcium signaling defect was recapitulated ex vivo through the introduction of this single variant in Jurkat cells. Moreover, site-directed mutagenesis displayed the exquisite sensitivity of Arg2524 to any amino acid change. In conclusion, a single unique recurrent de novo variant in ITPR3 leads to a novel syndromic immunodeficiency.
Project description:We reported previously that chronic treatment with the Cyclooxygenase-2 inhibitor, rofecoxib, increased acute mortality in rats exposed to ischemia/reperfusion injury (I/R). This manifestation of hidden cardiotoxicity was attributed to the proarrhythmic effect of the drug on the ischemic heart. However, rofecoxib also had beneficial effects on ischemic injury, manifesting as decreased infarct size. In the present study, we aimed to identify molecular changes caused by chronic rofecoxib treatment in the heart. Rats were treated with 5.12 mg/kg rofecoxib or its vehicle for four weeks. Messenger RNA (mRNA), microRNA (miRNA) deep sequencing data, and proteomic datasets of left ventricular tissue samples were used for an unbiased differential expression analysis followed by in silico molecular network analysis and experimental target validation. Using mass spectrometry and filtering criteria, 26 proteins were identified that exhibited pronounced changes in protein expression or phosphorylation due to chronic rofecoxib treatment. The transcriptomic analysis showed mild alterations in the heart´s mRNA- and miRNA expression. The posttranscriptional regulation of mRNAs by miRNAs did not result in differential protein expression. This is the first demonstration that chronic rofecoxib treatment affects posttranslational modification and expression of several proteins in the heart. These are potential off-target effects that could account for the hidden cardiotoxic and/or cardioprotective effects of rofecoxib.
Project description:To investigate the transcriptomic changes associated with ARDS progression, we performed RNA-seq on PBMCs from 6 healthy donors (Con), 7 ARDS patients
Project description:A 45h time-course RNA-seq study was performed to analyse the different circadian phenotypes of human colorectal cancer cell line HCT116 WT, HCT116 ARNTL Knockout, HCT116 PER2 Knockout and HCT116 NR1D1 Knockout cells. Samples were taken every 3h starting from 9h after cell synchronization for a period of 45h resulting in 16 time-points for each cell line.
Project description:In cyanobacteria and red algae, the structural basis dictating efficient excitation energy transfer from the phycobilisome (PBS) antenna complex to the reaction centers (RCs) remains unclear. PBS has several peripheral rods and a central core, which binds to the thylakoid membrane, allowing energy coupling with Photosystems II (PSII) and Photosystem I (PSI). Here, we integrated chemical cross-linking mass spectrometry with homology modeling analysis to propose a tri-cylindrical cyanobacterial PBS-core structure. Our model reveals a side view crossover configuration of the two basal cylinders, consolidating the essential roles of the anchoring domains comprised of the ApcE PB-loop and ApcD, which facilitate the energy transfer to PSII and PSI respectively. The uneven bottom surface of the PBS-core contrasts with the flat reducing side of PSII. The extra space between two basal cylinders of the PBS-core and PSII provides increased accessibility of regulatory elements, e.g., orange carotenoid protein, which are required for modulating photochemical activities.
Project description:We reported previously that chronic treatment with the Cyclooxygenase-2 inhibitor, rofecoxib, increased acute mortality in rats exposed to ischemia/reperfusion injury (I/R). This manifestation of hidden cardiotoxicity was attributed to the proarrhythmic effect of the drug on the ischemic heart. However, rofecoxib also had beneficial effects on ischemic injury, manifesting as decreased infarct size. In the present study, we aimed to identify molecular changes caused by chronic rofecoxib treatment in the heart. Rats were treated with 5.12 mg/kg rofecoxib or its vehicle for four weeks. Messenger RNA (mRNA), microRNA (miRNA) deep sequencing data, and proteomic datasets of left ventricular tissue samples were used for an unbiased differential expression analysis followed by in silico molecular network analysis and experimental target validation. Using mass spectrometry and filtering criteria, 26 proteins were identified that exhibited pronounced changes in protein expression or phosphorylation due to chronic rofecoxib treatment. The transcriptomic analysis showed mild alterations in the heart´s mRNA- and miRNA expression. The posttranscriptional regulation of mRNAs by miRNAs did not result in differential protein expression. This is the first demonstration that chronic rofecoxib treatment affects posttranslational modification and expression of several proteins in the heart. These are potential off-target effects that could account for the hidden cardiotoxic and/or cardioprotective effects of rofecoxib.