The Hedgehog (Hh) signaling pathway is fundamental to embryogenesis, tissue homeostasis, and cancer. Hh signals are transduced via an unusual mechanism: upon agonist-induced phosphorylation, the noncanonical G protein-coupled receptor SMOOTHENED (SMO) binds the catalytic subunit of protein kinase A (PKA-C) and physically blocks its enzymatic activity. By combining computational structural approaches with biochemical and functional studies, we show that SMO mimics strategies prevalent in canonical GPCR and PKA signaling complexes, despite little sequence or secondary structural homology.
View Article and Find Full Text PDFProximity labeling (PL) via biotinylation coupled with mass spectrometry (MS) captures spatial proteomes in cells. Large-scale processing requires a workflow minimizing hands-on time and enhancing quantitative reproducibility. We introduced a scalable PL pipeline integrating automated enrichment of biotinylated proteins in a 96-well plate format.
View Article and Find Full Text PDFProteins congregate into complexes to perform fundamental cellular functions. Phenotypic outcomes, in health and disease, are often mechanistically driven by the remodeling of protein complexes by protein-coding mutations or cellular signaling changes in response to molecular cues. Here, we present an affinity purification-mass spectrometry (APMS) proteomics protocol to quantify and visualize global changes in protein-protein interaction (PPI) networks between pairwise conditions.
View Article and Find Full Text PDFContext: Gastric cancer (GC) is a common and life-threatening gastrointestinal malignancy. Although mucin 3A (MUC3A) is an essential oncogenic factor in several cancers, limited information is available on its expression in GC tissues and its impact on prognosis.
Objective: The study aimed to characterize MUC3A in GC and to explore its potential involvement in regulating GC cells' behavior through the mammalian target of rapamycin (mTOR) signaling pathway.
The μ-opioid receptor (μOR) represents an important target of therapeutic and abused drugs. So far, most understanding of μOR activity has focused on a subset of known signal transducers and regulatory molecules. Yet μOR signaling is coordinated by additional proteins in the interaction network of the activated receptor, which have largely remained invisible given the lack of technologies to interrogate these networks systematically.
View Article and Find Full Text PDFTranslating high-confidence (hc) autism spectrum disorder (ASD) genes into viable treatment targets remains elusive. We constructed a foundational protein-protein interaction (PPI) network in HEK293T cells involving 100 hcASD risk genes, revealing over 1,800 PPIs (87% novel). Interactors, expressed in the human brain and enriched for ASD but not schizophrenia genetic risk, converged on protein complexes involved in neurogenesis, tubulin biology, transcriptional regulation, and chromatin modification.
View Article and Find Full Text PDFSARS-CoV-2 variants of concern (VOCs) emerged during the COVID-19 pandemic. Here, we used unbiased systems approaches to study the host-selective forces driving VOC evolution. We discovered that VOCs evolved convergent strategies to remodel the host by modulating viral RNA and protein levels, altering viral and host protein phosphorylation, and rewiring virus-host protein-protein interactions.
View Article and Find Full Text PDFProximity labeling (PL) through biotinylation coupled with mass spectrometry (MS) has emerged as a powerful technique for capturing spatial proteomes within living cells. Large-scale sample processing for proximity proteomics requires a workflow that minimizes hands-on time while enhancing quantitative reproducibility. Here, we present a scalable PL pipeline integrating automated enrichment of biotinylated proteins in a 96-well plate format.
View Article and Find Full Text PDFClostridioides difficile infection (CDI) causes severe diarrhea and colitis, leading to significant morbidity, mortality, and high medical costs worldwide. Oral vancomycin, a first-line treatment for CDI, is associated with a high risk of recurrence, necessitating novel therapies for primary and recurrent CDI. A novel small-molecule compound, CDBN-YGXZ, was synthesized by modifying the benzene ring of nitazoxanide with lauric acid.
View Article and Find Full Text PDFGastric cancer (GC) is one of the most malignant tumors with high incidence and poor prognosis. Currently, the combination of surgery with chemo- or radiotherapy is widely applied therapeutic strategy against GC. However, development of drug resistance severely limited the clinical application of chemotherapy.
View Article and Find Full Text PDFEnteroviruses cause a number of medically relevant and widespread human diseases with no approved antiviral therapies currently available. Host-directed therapies present an enticing option for this diverse genus of viruses. We have previously identified the actin histidine methyltransferase SETD3 as a critical host factor physically interacting with the viral protease 2A.
View Article and Find Full Text PDFLarge cell neuroendocrine carcinoma (LCNEC) is a rare histological subtype of ovarian cancer. A few cases have been reported in the literature with extreme invasiveness and a poor prognosis. However, there still have not been accepted criteria for diagnosis and treatment of LCNEC.
View Article and Find Full Text PDFIn spite of improvements in diagnostics and treatment of gastric cancer (GC), it remains the most common malignancy of human digestive system. It is now widely appreciated that long noncoding RNAs (lncRNAs) exert extensive regulatory effects on a spectrum of fundamental biological processes through diverse mechanisms. In this study, we explored the expression level and functional role of lncRNA RP11-138J23.
View Article and Find Full Text PDFDysregulation of the long noncoding RNA GAS5 in human cancer has been identified in recent studies. In this study, we confirmed a negative correlation between the GAS5 expression level and papillary thyroid carcinoma clinicopathologic characteristics, such as the tumor size, lymph node metastasis, the TNM stage and BRAF mutation. The viability and metastasis of papillary thyroid carcinoma cells were detected by CCK-8 and transwell assays, respectively.
View Article and Find Full Text PDFDifferentiation proceeds along a continuum of increasingly fate-restricted intermediates, referred to as canalization. Canalization is essential for stabilizing cell fate, but the mechanisms that underlie robust canalization are unclear. Here we show that the BRG1/BRM-associated factor (BAF) chromatin-remodelling complex ATPase gene Brm safeguards cell identity during directed cardiogenesis of mouse embryonic stem cells.
View Article and Find Full Text PDFMolecular switch proteins whose cycling between states is controlled by opposing regulators are central to biological signal transduction. As switch proteins function within highly connected interaction networks, the fundamental question arises of how functional specificity is achieved when different processes share common regulators. Here we show that functional specificity of the small GTPase switch protein Gsp1 in Saccharomyces cerevisiae (the homologue of the human protein RAN) is linked to differential sensitivity of biological processes to different kinetics of the Gsp1 (RAN) switch cycle.
View Article and Find Full Text PDFThe Hedgehog (Hh) pathway is essential for organ development, homeostasis, and regeneration. Dysfunction of this cascade drives several cancers. To control expression of pathway target genes, the G protein-coupled receptor (GPCR) Smoothened (SMO) activates glioma-associated (GLI) transcription factors via an unknown mechanism.
View Article and Find Full Text PDFDetermining structures of protein complexes is crucial for understanding cellular functions. Here, we describe an integrative structure determination approach that relies on in vivo measurements of genetic interactions. We construct phenotypic profiles for point mutations crossed against gene deletions or exposed to environmental perturbations, followed by converting similarities between two profiles into an upper bound on the distance between the mutated residues.
View Article and Find Full Text PDFWe present the case of a woman diagnosed with a teratoma adherent to the vaginal wall. The patient had been misdiagnosed with an ovarian teratoma 8 years previously at her local hospital, but no mass was found in the pelvic cavity during cesarean section. She therefore attended our institution for further examination.
View Article and Find Full Text PDFThe COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a grave threat to public health and the global economy. SARS-CoV-2 is closely related to the more lethal but less transmissible coronaviruses SARS-CoV-1 and Middle East respiratory syndrome coronavirus (MERS-CoV). Here, we have carried out comparative viral-human protein-protein interaction and viral protein localization analyses for all three viruses.
View Article and Find Full Text PDFThe causative agent of the coronavirus disease 2019 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected millions and killed hundreds of thousands of people worldwide, highlighting an urgent need to develop antiviral therapies. Here we present a quantitative mass spectrometry-based phosphoproteomics survey of SARS-CoV-2 infection in Vero E6 cells, revealing dramatic rewiring of phosphorylation on host and viral proteins. SARS-CoV-2 infection promoted casein kinase II (CK2) and p38 MAPK activation, production of diverse cytokines, and shutdown of mitotic kinases, resulting in cell cycle arrest.
View Article and Find Full Text PDFAn outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 290,000 people since the end of 2019, killed over 12,000, and caused worldwide social and economic disruption. There are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Unfortunately, the scientific community has little knowledge of the molecular details of SARS-CoV-2 infection.
View Article and Find Full Text PDFA newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells.
View Article and Find Full Text PDFWe have developed a platform for quantitative genetic interaction mapping using viral infectivity as a functional readout and constructed a viral host-dependency epistasis map (vE-MAP) of 356 human genes linked to HIV function, comprising >63,000 pairwise genetic perturbations. The vE-MAP provides an expansive view of the genetic dependencies underlying HIV infection and can be used to identify drug targets and study viral mutations. We found that the RNA deadenylase complex, CNOT, is a central player in the vE-MAP and show that knockout of CNOT1, 10, and 11 suppressed HIV infection in primary T cells by upregulating innate immunity pathways.
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