ABSTRACT: Peptide pulldowns with C-man antibodies to demostrate the utelity of reagents for proteomic analysis. Using Murine brain samples Novel C-man sites are readily identifiable.
Project description:Dynamic cycling of N-Acetylglucosamine (GlcNAc) on serine (Ser) and threonine (Thr) residues (O-GlcNAcylation) is an essential process in all eukaryotic cells except yeast, e.g Saccharomyces cerevisiae. O-GlcNAcylation modulates signaling and cellular processes in an intricate interplay with protein phosphorylation, and serves as a key sensor of nutrients by linking the hexosamine biosynthetic pathway (HBP) to cellular signaling. A longstanding conundrum has been how yeast survives without O-GlcNAcylation in light of its similar phosphorylation signaling system. We previously developed a sensitive lectin enrichment and mass spectrometry workflow for identification of the human O-Mannose (O-Man) glycoproteome, and used this to identify a pleothora of O-linked mannose glycoproteins in human cell lines including the large family of cadherins and protocadherins. Here, we applied the workflow to yeast with the aim to characterize the yeast O-Man glycoproteome, and doing so we discovered hitherto unknown O-Man glycosites on nuclear, cytoplasmic and mitochondrial proteins in Saccharomyces cerevisiae. The type of nucleocytoplasmic proteins and the localization of identified O-Man residues mirrors that of the O-GlcNAc glycoproteome in other eukaryotic cells, indicating that the two different types of O-glycosylations serve the same important biological functions. The discovery opens for exploration of the enzyme machinery that is predicted to regulate the discovered nucleocytoplasmic O-Man glycosylation. It is likely that manipulation of this type of O-Man glycosylation will have wide applications for yeast bioprocessing.
Project description:Repo-Man chromatin binding sites were obtained by expression of GST:Repo-Man and incubation with nucleosomes extracted from HeLa cells (GST alone signal was used as a negative control and subtracted from the GST:Repo-Man chromatin bound fraction)
Project description:GST:Repo-Man(C-terminus) or GST:alone were expressed as in Vagnarelli et al. 2011. Before elution, beads were first incubated with nucleosomes extracted from HeLa. HeLa cells were lysed and nucleosomes were digested with MNase (20min, 37C). Nucleosomes were firstly incubated with GST alone for 2hrs. This cleared lysate was then incubated with GST:Repo-Man and GST alone. Beads were then eluted and mix with 3x Laemli Buffer. Histone bands were sent to Mass Spec.
Project description:With a view to developing a much-needed non-invasive method for monitoring the healthy pluripotent state of human stem cells in culture, we undertook proteomic analysis of the waste medium from cultured induced (Rebl.PAT) human pluripotent stem cells (hPSCs). Cells were grown in E8 medium to maintain pluripotency, and then transferred to FGF2 and TGFβ deficient E6 media for 48 hours to replicate an early, undirected dissolution of pluripotency. We identified a distinct proteomic footprint associated with early loss of pluripotency in both hPSC lines, and a strong correlation with changes in the transcriptome. We demonstrate that multiplexing of four E8- against four E6- enriched secretome biomarkers provides a robust, diagnostic metric for pluripotent state. These biomarkers were further confirmed by Western blotting which demonstrated consistent correlation with the pluripotent state across cell lines, and in response to a recovery assay.
Project description:Serial analysis of gene expression (SAGE) was used to get a global view of the gene profile in human hippocampus. A library were generated from control hippocampus, obtained by rapid autopsy. Keywords: hippocampus human inventory genes Control hippocampus (used to construct the SAGE control library) was obtained from a 48 years old man without history of seizures or other neurological diseases and no brain abnormalities at autopsy and histologically normal hippocampus. Autopsy was performed within 4 hours after death. Tissue was snap-frozen and stored at –80 0C until use. Total RNA was isolated from control hippocampus and hippocampal surgical specimens, using the Trizol method according to the manufacturer’s instructions (Invitrogen - Life Technologies, The Netherlands). Part of the anterior hippocampus of control (including sectors CA1- CA4 and dentate gyrus, DG) was used. Poly(A)+ RNA isolation, cDNA synthesis and all subsequent steps of the SAGE procedure were essentially performed as described (Velculescu et al., 1995) with minor modifications given previously (Michiels et al., 1999).
Project description:mzXML files of MS/MS data from skin swab samples of 1 man volunteer. Samples were collected from 17 spots on a man face, everyday during 10 days. MS/MS data collected from beauty products used by this subject are also included.
Project description:The androgen receptor (AR) is the major transcriptional driver of prostate cell growth in man. For the first time, we define AR targets in prostate cancer (PC) tissue representing progression from treatment-naive to castrate-resistant disease (CRPC). We employed chromatin immunoprecipitation with high through-put sequencing (ChIP-seq) in human tissue, with cell-line and xenograft studies. We uncovered an AR transcriptional network not observed in cultured cells, with significant over-representation of MYC, E2F and STAT binding sites, progenitor cell gene signatures and targets which regulate metabolism, cell cycle and steroid biosynthesis. We identified AR targets unique to CRPC tissue, with a subset over-expressed in CRPC and predictive of clinical outcome, highlighting persistence of AR signalling. Our data support a model whereby endocrine and paracrine signals converge on the AR in PC tissue to drive oncogenic transcriptional programs, highlighting the critical role of cellular context in the regulation of target selection and gene expression.