Project description:This experiments follows up ChIPseq experiments and aims to investigate the role of Rad50 on gene expression in drosophila larval stage 3 CNS.
Project description:Posttranslational modification of proteins by N-linked glycosylation is crucial for many life processes. However, the exact contribution of N-glycosylation to mammalian female reproduction remains largely undefined. Here, DPAGT1, the enzyme that catalyzes the first step of protein N-glycosyation, is identified to be indispensable for oocyte development in mice. A recessive missense mutation (c. 497A>G; p. Asp166Gly) of Dpagt1 causes female subfertility without grossly affecting other functions. Mutant females ovulate fewer eggs owing to defects of follicular development beyond the late secondary stage. Oocytes ovulated by mutants carry a thin and fragile zona pellucida, and display poor developmental competence after fertilization in vitro. Moreover, completion of the first meiosis is accelerated in mutant oocytes, which is coincident with the elevation of aneuploidy. Mechanistically, transcriptomic analysis reveals the downregulation of a number of transcripts essential for oocyte meiotic progression and preimplantation development (e.g., Pttgt1, Esco2, Orc6, and Npm2) in mutant oocytes, which could account for the defects observed. Furthermore, conditional knockout (CKO) of Dpagt1 in oocytes recapitulates the phenotypes observed in Dpagt1 mutant females, and causes complete infertility. Taken together, these data indicate that protein N-glycosylation in oocytes is essential for female fertility in mammals by specific control of oocyte development.
Project description:Cancer stem cells (CSCs) play crucial roles in cancer progression, immune evasion, drug resistance, and recurrence. Understanding the mechanisms behind CSCs generation and stemness maintenance is vital for early cancer diagnosis and treatment. Here, we unveil that carnitine palmitoyltransferase 1A (CPT1A) is highly expressed in ovarian cancer stem cells (OCSCs) and is essential for maintaining stemness by regulating lipid desaturation. Studies confirmed that CPT1A enhances SREBP1 activation, upregulating SCD1 expression, and promoting lipid desaturation in OCSCs. Mechanistic studies reveal that CPT1A promotes succinylation of mitochondrial fission factor (MFF) through its lysine succinyltransferase (LSTase) activity, crucial for mitochondria-associated membranes formation and SREBP1 activation. Inhibiting CPT1A's LSTase activity with Glyburide reduces OCSCs' stemness and enhances cisplatin's anti-tumor effects against ovarian cancer in vitro and in vivo. Together, our studies highlight the significance of CPT1A's LSTase activity in maintaining OCSCs' stemness, offering potential targets and therapeutic strategies for ovarian cancer treatment.
Project description:EGF is one of the most well-characterized growth factors and plays a crucial role in cell proliferation and differentiation. EGFR has been extensively explored as a therapeutic target against multiple types of cancers, such as lung cancer and glioblastoma. Recent studies have established a connection between deregulated EGF signaling and metabolic reprogramming, especially rewiring in aerobic glycolysis, which is also known as the Warburg effect and recognized as a hallmark in cancer. Pyruvate kinase M2 (PKM2) is a rate-limiting enzyme controlling the final step of glycolysis and serves as a major regulator of the Warburg effect. We previously showed that PKM2 T405/S406 O-GlcNAcylation, a critical mark important for PKM2 detetramerization and activity, was markedly upregulated by EGF. However, the mechanism by which EGF regulates PKM2 O-GlcNAcylation still remains uncharacterized. Here we demonstrated that EGF promoted O-GlcNAc transferase (OGT) binding to PKM2 by stimulating OGT Y976 phosphorylation. As a consequence, PKM2 O-GlcNAcylation and detetramerization were upregulated, leading to a significant decrease in PKM2 activity. Moreover, other than PKM2, the association of additional phosphotyrosine binding proteins, including STAT1, STAT3, STAT5, PKCδ and p85, which are reported factors bearing O-GlcNAcylation, with OGT was also enhanced when Y976 was phosphorylated. Together, EGF-dependent Y976 phosphorylation is critical for OGT-PKM2 interaction and we propose that this post-translational modification might be important for the substrate selection by OGT.
Project description:Decoding protein C-termini is a challenging task in protein chemistry using conventional chemical/enzymatic approaches. With the rapid development in modern mass spectrometer, many advanced mass spectrometry (MS) based protein C-termini analysis approaches have been established. Although great progresses have been continually achieved, it is still nec-essary to develop more efficient approaches in order to discover a proteome-scale protein C-termini (C-terminome), and consequently to help understand their biological functions. In this report, we describe a simple method, termed BaSCX, for basic strong cation exchange chromatography, to study C-terminome.
Project description:Metastatic BRAFV600E colorectal cancer (CRC) confers poor prognosis and run into a bottleneck in the current treatment strategies. To identify regulatory pathways independent of the MAPK pathway in BRAFV600E CRC, we performed CRISPR-Cas9 screening, and and find targeting glutathione peroxidase 4 (GPX4) remarkably overcome BRAF inhibitor (BRAFi) ± epidermal growth factor receptor (EGFR) inhibitor (EGFRi) resistance in BRAFV600E CRC. Specifically, BRAFi ± EGFRi induced GPX4 upregulated expression and antagonized ferroptosis. Moreover, polo-like kinase 1 (PLK1) substrate activation promoted PLK1 translocation to the nucleus, activating chromobox protein homolog 8 (CBX8) phosphorylation at Ser265, which induce GPX4 expression. Targeting PLK1 promoted BRAFi ± EGFRi inhibition and triggered ferroptosis in vitro, vivo, organoid, and patient-derived xenograft model. Collectively, we demonstrate a novel PLK1–CBX8–GPX4 signaling axis relaying the ferroptosis mechanism of therapeutic resistance operated independent of MAPK signaling and suggest a clinically actionable strategy to overcome BRAFi ± EGFRi resistance in BRAFV600E CRC.
Project description:Data for the third YPIC Challenge. A synthetic peptide was analyzed using HR-MS. The peptide contains a codeword/phrase/sentence. Can you decrypt it? Get your best mates and try to crack the challenge!
Project description:MSC-EV exerts their effects by transferring cargo components into target cells. Given that extracellular vesicles (EV) can deliver diverse cargo to recipient cells and elicit similar therapeutic effects, we investigate the cargo of both adipose-derived MSC-derived EV (AMSC-EV) and umbilical cord-derived MSC-derived EV (HUMSC-EV).As a crucial component of EV cargo, proteins are known to exert significant influence on EV functions. We performed a protein analysis of MSC-EV.
Project description:Identification of factors in conditioned media of first-trimester placental villous explants. Explants were cultured under hypoxia (2% O2), 5% CO2 in serum-free DMEM/F12 and treated with recombinant galectin-7 (1ug/ml) or vehicle control (BSA) for 72h. Identification of factors in conditioned media of first-trimester placental villous explants. Explants were cultured under superoxia (20% O2), 5% CO2 in serum-free DMEM/F12 and treated with recombinant galectin-7 (1ug/ml) or vehicle control (BSA) for 72h.
Project description:Identification of cellular proteins in human endometrial stromal fibroblasts decidualized for 13 days in vitro. Fibroblasts were cultured under normal culture conditions (5% CO2 in 2% charcoal stripped FBS) and treated with prednisolone (0.5ug/ml) or vehicle control (DMSO) every 48-72h for 13 days