A suite of tools for the study of tryptophan C-mannosylation
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Orbitrap Fusion Lumos, Q Exactive
ORGANISM(S): Homo Sapiens (human)
SUBMITTER: 
Nichollas Scott
LAB HEAD: Ethan Goddard-Borger
PROVIDER: PXD018401 | Pride | 2020-11-16
REPOSITORIES: Pride
Similar Datasets
Project description:Tryptophan C-mannosylation is an unusual co-translational protein modification performed by metazoans and apicomplexan parasites. The prevalence of this modification and its biological function is poorly understood, with progress being hampered by a dearth of tools for its study. Here, we engineer of a simple yeast system to enable the production of a diverse array of proteins with and without the modification to interrogate its effect on protein stability and function. This system also facilitated mutagenesis studies, to elucidate what features of the glycosyltransferase and its substrates are crucial for catalysis, and expedited the generation and thorough characterisation of monoclonal antibodies against the protein modification. These antibodies empowered proteomic analyses of the brain C-glycome by enriching for peptides possessing tryptophan C-mannosylation, which revealed new modification sites on difficult-to-study proteins throughout the secretory pathway on both conventional and non-canonical consensus sequences.
2020-11-16 | PXD021612 | Pride
Project description:C-mannosylation in addition to N- and O-glycosylation is a further but less well studied type of protein glycosylation taking place in the endoplasmic reticulum (ER) characterised by the modification of tryptophan residues with a single mannose effecting protein folding, secretion and/or function. Motivated by an interest in the functional role of C-mannosylation for early developmental processes, we aimed for the functional inactivation of the C mannosyltransferases DPY19L1 and DPY19L3, respectively, and excised parts of their coding sequence from the genome of the hiPSC line CBiPSC2 by applying CRISPR Cas9. To determine the effect of the genomic deletions in DPY19L1 or DPY19L3 on C-mannosylation, TSR2 and TSR3 of human thrombospondin 1 (THBS1) was recombinantly expressed in WT and KO hiPSCs followed by purification an LC-MS analysis. The results are in accordance to our previous findings that DPY19L1 is mainly acting on W1 and W2 whereas DPY19L3 acts on W3 of WxxWxxWxxC motifs of TSRs and proves the functional inactivation of the respective C-mannosyltransferases in the hiPSCs model. A secretome analysis of C mannosyltransferase deficient hiPSCs revealed that secretion of numerous proteins was reduced in the mutants including ADAMTS16, which was previously reported to be essential for optic fissure fusion in zebrafish. In order to analyse C-mannosylation of ADAMTS16, its TSR1 was recombinantly expressed in CHO-K1 WT, DPY19L1 KO and DPY19L3 KO cells, purified and analysed by LC MS analysis. The results revealed that the WSDWSSWSPC motif of TSR1 of ADAMTS16 can be C-mannosylated at all three tryptophan residues. Deletion of DPY19L1 prevented C-mannosylation of the two first tryptophans whereas C-mannosylation of the third tryptophan was not detected in the DPY19L3-mutant.
2021-06-17 | PXD024192 | Pride
Project description:C-mannosylation is a modification of tryptophan residues with a single mannose effecting protein folding, secretion and/or function. To date, only few proteins have been proven to be C-mannosylated and studies aiming at global assessment of protein C-mannosylation from cells or tissues are scarce. In order to interrogate the C-mannosylome of human induced pluripotent stem cells (hiPSCs), we made use of the common finding that C-mannosylation is important for protein secretion. Thus we compared the secretomes of C-mannosyltransferase-deficient DPY19L1 and DPY19L3 mutants to their parental wild-type hiPSCs by mass-spectrometry-based quantitative proteomics. Secretion of numerous proteins was reduced in the mutants.
2021-06-17 | PXD024193 | Pride
Project description:Primary lymphoma of the central nervous system (PCNSL) is a diffuse large B cell lymphoma confined to the CNS. In order to elucidate its peculiar organ tropism, we generated recombinant antibodies (recAb) identical with the BCR of a series of 23 PCNSL from immunocompetent patients. While none of the recAb showed self-reactivity upon testing with common autoantigens, they recognized 1547 proteins present on a large-scale protein microarray. Interestingly, proteins recognized by the recAb are physiologically expressed by CNS neurons (GRINL1A, centaurin-α, BAIAP2). Furthermore, 87% (20/23) of the recAb including all antibodies derived from IGHV4 34 using PCNSL recognized galectin-3, which was upregulated on microglia/macrophages, astrocytes, and cerebral endothelial cells upon CNS invasion by PCNSL. Thus, PCNSL Ig may recognize CNS proteins as self-antigens. Their interaction may contribute to BCR signaling with sustained NF-κB activation and, ultimately, may foster tumor cell proliferation and survival. These data may also explain, at least in part, the affinity of the tumor cells of PCNSL to the CNS. Recombinant antibodies (recAb) identical with the BCR of a series of 23 PCNSL from immunocompetent patients.
2015-07-01 | E-GEOD-61556 | biostudies-arrayexpress
Project description:Type 1 diabetes mellitus (T1DM) results from immune mediated destruction of pancreatic beta cells. However, clinical and immunologic phenotypes of T1DM are variable. Several auto-antibodies including GADA, IA-2A, and ZnT8A, were identified in T1DM, but the prevalence of these auto-antibodies varied for a broad spectrum of T1DM. Here, we systemically profiled auto-antibodies from serum samples of 16 T1DM, 16 type 2 diabetes (T2DM) patients, and 27 healthy controls with normal glucose tolerance (NGT) using protein microarrays containing 9,480 proteins. Among 9,480 different proteins on the array, we identified novel auto-antibody candidates (EEF1A1-AAb and UBE2L3-AAb) by M-test coupled with PLS-DA. These auto-antibodies were highly present in T1DM than controls and detected in 40% of T1DM without GADA. Furthermore, these auto-antibodies might help to differentiate subtype of T1DM when combined with GADA. These novel auto-antibodies provide new diagnostic information of T1DM, as well as new insights into the pathogenesis of T1DM. Auto-antibodies from serum samples were profiled using a high-density, fluorescence-based protein microarray containing duplicate spots of 9,480 human proteins derived from the Ultimate ORF collection The cohort of patients and controls consisted of 16 T1DM, 16 T2DM patients, and 27 healthy controls with NGT. This cohort was used to screen candidate auto-antibodies using protein microarrays (ProtoArray platform version 5.0, Invitrogen Corp., Carlsbad, CA). Serum samples were drawn from T1DM patients who have 1) fasting C-peptide level <0.3 nmol/L or serum C-peptide <0.6 nmol/L after glucagon loading, 2) initiation of insulin treatment within six months after diagnosis, and 3) duration of diabetes M-bM-^IM-$12 months. Mean age of T1DM in the first cohort was 42 M-BM-1 16 years. The control serum samples were obtained from T2DM patients who were treated only with oral anti-diabetic drug at least 5 years and from NGTs who had no history of diabetes, no first-degree relatives with diabetes, a fasting plasma glucose concentration of <6.1 mmol/l, and a HbA1c value of <5.8%.
2014-07-30 | E-GEOD-50866 | biostudies-arrayexpress
Project description:Protein O-mannosylation is found in yeast and metazoans and a family of conserved orthologous polypeptide O-mannosyltransferases is believed to initiate this important posttranslational modification. We recently discovered that the large families of cadherins and protocadherins carry highly conserved O-Man glycans in specific EC domains, and it was suggested that the function of E-Cadherin was dependent on the O-Man glycans. Deficiencies in the two human polypeptide O-mannosyltransferases, POMT1 and T2, underlie a subgroup of congenital muscular dystrophies (CMD) designated α-dystroglycanopathies, because deficient O-Man glycans on -dystroglycan impair laminin interaction with -dystroglycan and the dystrophin complex. In order to explore the functions of O-Man glycans on cadherins and protocadherins we used a combinatorial gene editing strategy in multiple cell lines to evaluate to the role of the two POMTs initiation O-Man glycosylation and the major enzyme elongating O-Man glycans, the POMGNT1 2GlcNAc-transferase. Surprisingly, we discovered that O-Man glycans on cadherins and protocadherins do not appear to require POMT1 and T2 and moreover that the O-Man glycans on these proteins are not elongated in contrast to those on dystroglycan.
2017-05-18 | PXD004358 | Pride
Project description:Protein O-mannosylation is found in yeast and metazoans and a family of conserved orthologous polypeptide O-mannosyltransferases is believed to initiate this important posttranslational modification. We recently discovered that the large families of cadherins and protocadherins carry highly conserved O-Man glycans in specific EC domains, and it was suggested that the function of E-Cadherin was dependent on the O-Man glycans. Deficiencies in the two human polypeptide O-mannosyltransferases, POMT1 and T2, underlie a subgroup of congenital muscular dystrophies (CMD) designated α-dystroglycanopathies, because deficient O-Man glycans on -dystroglycan impair laminin interaction with -dystroglycan and the dystrophin complex. In order to explore the functions of O-Man glycans on cadherins and protocadherins we used a combinatorial gene editing strategy in multiple cell lines to evaluate to the role of the two POMTs initiation O-Man glycosylation and the major enzyme elongating O-Man glycans, the POMGNT1 2GlcNAc-transferase. Surprisingly, we discovered that O-Man glycans on cadherins and protocadherins do not appear to require POMT1 and T2 and moreover that the O-Man glycans on these proteins are not elongated in contrast to those on dystroglycan.
2017-05-18 | PXD004341 | Pride
Project description:C-mannosylation stabilizes proteins bearing a thrombospondin repeat (TSR) domain in metazoans. Here we show that Plasmodium falciparum expresses a DPY19 C-mannosyltransferase in the endoplasmic reticulum and that DPY19-deficiency abolishes C-glycosylation, destabilizes members of the TRAP adhesin family and inhibits transmission to mosquitoes. P. falciparum gametogenesis was imaged in its entirety in four dimensions using lattice light-sheet microscopy. This revealed defects in egress and exflagellation for DPY19 microgametes. While exflagellation was diminished, DPY19 microgametes still fertilized macrogametes, forming ookinetes but these were abrogated for mosquito infection. The gametogenesis defects corresponded with destabilization of MTRAP, which we show is C-mannosylated in P. falciparum, and the ookinete defect was concordant with defective CTRP secretion on the DPY19 background. Genetic complementation of DPY19 restored ookinete infectivity, sporozoite production and C-mannosylation activity. Therefore, tryptophan C-mannosylation by DPY19 in the early secretory pathway ensures TSR protein quality control at two lifecycle stages for successful transmission of the human malaria parasite.
2022-07-06 | PXD033470 | Pride
Project description:The present study describes a novel xenograft-based biomarker discovery platform and proves its usefulness in the discovery of novel serum markers for prostate cancer (PCa). By immunizing immuno-competent mice with serum from nude mice bearing PCa xenografts, an antibody response against xenograft-derived antigens was elicited. By probing protein microarrays with serum from immunized mice, several PCa-derived antigens were identified, of which a subset was successfully retrieved in serum from mice bearing PCa xenografts and validated in human serum samples of PCa patients. In conclusion, this novel method allows for the identification of low abundant cancer-derived serum proteins, circumventing dynamic range and host-response issues in standard patient cohort proteomics comparisons. To perform a large-scale identification of antibodies generated against human PCa-derived proteins in the serum of immunized mice, sera from mice immunized with either depleted serum, full serum or both from PC346 and PC339-bearing mice as well as preimmune serum and serum from mice immunized with normal mouse serum were incubated onto ProtoArrays. These ProtoArrays contain approximately 8,000 partial and full-length human proteins, expressed as N-terminal glutathione S-transferase (GST) fusion proteins. To detect antibodies bound to spotted proteins, ProtoArrays were developed using a fluorescent labeled secondary antibody. Before being used for immunization, serum from xenografted mice was not treated (full) or depleted for most abundant proteins (depleted). Two arrays were hybridized with pre-immune serum and one array with serum from an immune competent mouse that was immunized with serum from a nude mouse. Six arrays were performed using serum from immune competent mice that were immunized with serum from xenograft-bearing nude mice.
2011-12-16 | E-GEOD-16220 | biostudies-arrayexpress
Project description:Mathematical modeling of cancer-immune system, considering the role of antibodies.
Ghosh S1, Banerjee S2.
Author information
1
Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee, Uttaranchal, 247667, India.
2
Department of Mathematics, Indian Institute of Technology Roorkee, Roorkee, Uttaranchal, 247667, India. sandofma@iitr.ac.in.
Abstract
A mathematical model for the quantitative analysis of cancer-immune interaction, considering the role of antibodies has been proposed in this paper. The model is based on the clinical evidence, which states that antibodies can directly kill cancerous cells (Ivano et al. in J Clin Investig 119(8):2143-2159, 2009). The existence of transcritical bifurcation, which has been proved using Sotomayor theorem, provides strong biological implications. Through numerical simulations, it has been illustrated that under certain therapy (like monoclonal antibody therapy), which is capable of altering the parameters of the system, cancer-free state can be obtained.
KEYWORDS:
Antibodies; B cells; Cancer cells; Global stability; Plasma cells; Transcritical bifurcation
2019-12-09 | BIOMD0000000885 | BioModels