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1.
J Biol Chem ; 298(12): 102616, 2022 12.
Article in English | MEDLINE | ID: mdl-36265581

ABSTRACT

NOTCH1 is a transmembrane receptor that initiates a signaling pathway involved in embryonic development of adult tissue homeostasis. The extracellular domain of NOTCH1 is composed largely of epidermal growth factor-like repeats (EGFs), many of which can be O-fucosylated at a specific consensus sequence by protein O-fucosyltransferase 1 (POFUT1). O-fucosylation of NOTCH1 is necessary for its function. The Notch pathway is deregulated in many cancers, and alteration of POFUT1 has been reported in several cancers, but further investigation is needed to assess whether there is deregulation of the Notch pathway associated with mutations that affect O-fucosylation in cancers. Using Biomuta and COSMIC databases, we selected nine NOTCH1 variants that could cause a change in O-fucosylation of key EGFs. Mass spectral glycoproteomic site mapping was used to identify alterations in O-fucosylation of EGFs containing the mutations. Cell-based NOTCH-1 signaling assays, ligand-binding assays, and cellsurface analysis were used to determine the effect of each mutation on Notch activation. Two variants led to a gain of function (GOF), six to a loss of function (LOF), and one had minimal effects. Most GOF and LOF were associated with a change in O-fucosylation. Finally, by comparing our results with known NOTCH1 alterations in cancers from which our mutations originated, we were able to establish a correlation between our results and the known GOF or LOF of NOTCH1 in these cancers. This study shows that point mutations in N1 can lead to alterations in O-fucosylation that deregulate the Notch pathway and be associated with cancer processes.


Subject(s)
Neoplasms , Receptor, Notch1 , Signal Transduction , Humans , Fucosyltransferases/genetics , Fucosyltransferases/metabolism , Glycosylation , Neoplasms/genetics , Receptor, Notch1/genetics , Receptor, Notch1/metabolism , Point Mutation
2.
J Biol Chem ; 298(7): 102064, 2022 07.
Article in English | MEDLINE | ID: mdl-35623385

ABSTRACT

NOTCH1 is a transmembrane receptor that initiates a cell-cell signaling pathway controlling various cell fate specifications in metazoans. The addition of O-fucose by protein O-fucosyltransferase 1 (POFUT1) to epidermal growth factor-like (EGF) repeats in the NOTCH1 extracellular domain is essential for NOTCH1 function, and modification of O-fucose with GlcNAc by the Fringe family of glycosyltransferases modulates Notch activity. Prior cell-based studies showed that POFUT1 modifies EGF repeats containing the appropriate consensus sequence at high stoichiometry, while Fringe GlcNAc-transferases (LFNG, MFNG, and RFNG) modify O-fucose on only a subset of NOTCH1 EGF repeats. Previous in vivo studies showed that each FNG affects naïve T cell development. To examine Fringe modifications of NOTCH1 at a physiological level, we used mass spectral glycoproteomic methods to analyze O-fucose glycans of endogenous NOTCH1 from activated T cells obtained from mice lacking all Fringe enzymes or expressing only a single FNG. While most O-fucose sites were modified at high stoichiometry, only EGF6, EGF16, EGF26, and EGF27 were extended in WT T cells. Additionally, cell-based assays of NOTCH1 lacking fucose at each of those O-fucose sites revealed small but significant effects of LFNG on Notch-Delta binding in the EGF16 and EGF27 mutants. Finally, in activated T cells expressing only LFNG, MFNG, or RFNG alone, the extension of O-fucose with GlcNAc in the same EGF repeats was diminished, consistent with cooperative interactions when all three Fringes were present. The combined data open the door for the analysis of O-glycans on endogenous NOTCH1 derived from different cell types.


Subject(s)
Epidermal Growth Factor , Fucose , Receptor, Notch1/metabolism , Animals , Epidermal Growth Factor/metabolism , Fucose/metabolism , Glucosyltransferases , Glycosyltransferases/genetics , Glycosyltransferases/metabolism , Mice , Polysaccharides/metabolism , Receptors, Notch/metabolism , T-Lymphocytes/metabolism
3.
J Biol Chem ; 298(6): 102047, 2022 06.
Article in English | MEDLINE | ID: mdl-35597280

ABSTRACT

Thrombospondin type-1 repeats (TSRs) are small protein motifs containing six conserved cysteines forming three disulfide bonds that can be modified with an O-linked fucose. Protein O-fucosyltransferase 2 (POFUT2) catalyzes the addition of O-fucose to TSRs containing the appropriate consensus sequence, and the O-fucose modification can be elongated to a Glucose-Fucose disaccharide with the addition of glucose by ß3-glucosyltransferase (B3GLCT). Elimination of Pofut2 in mice results in embryonic lethality in mice, highlighting the biological significance of O-fucose modification on TSRs. Knockout of POFUT2 in HEK293T cells has been shown to cause complete or partial loss of secretion of many proteins containing O-fucosylated TSRs. In addition, POFUT2 is localized to the endoplasmic reticulum (ER) and only modifies folded TSRs, stabilizing their structures. These observations suggest that POFUT2 is involved in an ER quality control mechanism for TSR folding and that B3GLCT also participates in quality control by providing additional stabilization to TSRs. However, the mechanisms by which addition of these sugars result in stabilization are poorly understood. Here, we conducted molecular dynamics (MD) simulations and provide crystallographic and NMR evidence that the Glucose-Fucose disaccharide interacts with specific amino acids in the TSR3 domain in thrombospondin-1 that are within proximity to the O-fucosylation modification site resulting in protection of a nearby disulfide bond. We also show that mutation of these amino acids reduces the stabilizing effect of the sugars in vitro. These data provide mechanistic details regarding the importance of O-fucosylation and how it participates in quality control mechanisms inside the ER.


Subject(s)
Fucose , Fucosyltransferases , Thrombospondin 1 , Animals , Disaccharides , Disulfides , Endoplasmic Reticulum/metabolism , Fucose/metabolism , Fucosyltransferases/metabolism , Galactosyltransferases , Glucose , Glucosyltransferases/metabolism , HEK293 Cells , Humans , Mice , Molecular Dynamics Simulation , Thrombospondin 1/chemistry
4.
Glycobiology ; 33(4): 301-310, 2023 05 17.
Article in English | MEDLINE | ID: mdl-36721988

ABSTRACT

Thrombospondin 1 (THBS1) is a secreted extracellular matrix glycoprotein that regulates a variety of cellular and physiological processes. THBS1's diverse functions are attributed to interactions between the modular domains of THBS1 with an array of proteins found in the extracellular matrix. THBS1's three Thrombospondin type 1 repeats (TSRs) are modified with O-linked glucose-fucose disaccharide and C-mannose. It is unknown whether these modifications impact trafficking and/or function of THBS1 in vivo. The O-fucose is added by Protein O-fucosyltransferase 2 (POFUT2) and is sequentially extended to the disaccharide by ß3glucosyltransferase (B3GLCT). The C-mannose is added by one or more of four C-mannosyltransferases. O-fucosylation by POFUT2/B3GLCT in the endoplasmic reticulum has been proposed to play a role in quality control by locking TSR domains into their three-dimensional fold, allowing for proper secretion of many O-fucosylated substrates. Prior studies showed the siRNA knockdown of POFUT2 in HEK293T cells blocked secretion of TSRs 1-3 from THBS1. Here we demonstrated that secretion of THBS1 TSRs 1-3 was not reduced by CRISPR-Cas9-mediated knockout of POFUT2 in HEK293T cells and demonstrated that knockout of Pofut2 or B3glct in mice did not reduce the trafficking of endogenous THBS1 to secretory granules of platelets, a major source of THBS1. Additionally, we demonstrated that all three TSRs from platelet THBS1 were highly C-mannosylated, which has been shown to stabilize TSRs in vitro. Combined, these results suggested that POFUT2 substrates with TSRs that are also modified by C-mannose may be less susceptible to trafficking defects resulting from the loss of the glucose-fucose disaccharide.


Subject(s)
Fucosyltransferases , Thrombospondin 1 , Animals , Humans , Mice , Fucose/metabolism , Fucosyltransferases/metabolism , Glucose , HEK293 Cells , Mannose , Secretory Vesicles/metabolism , Thrombospondin 1/genetics , Thrombospondin 1/metabolism , Thrombospondins/genetics
5.
J Biol Chem ; 297(3): 101055, 2021 09.
Article in English | MEDLINE | ID: mdl-34411563

ABSTRACT

Fibrillin-1 (FBN1) is the major component of extracellular matrix microfibrils, which are required for proper development of elastic tissues, including the heart and lungs. Through protein-protein interactions with latent transforming growth factor (TGF) ß-binding protein 1 (LTBP1), microfibrils regulate TGF-ß signaling. Mutations within the 47 epidermal growth factor-like (EGF) repeats of FBN1 cause autosomal dominant disorders including Marfan Syndrome, which is characterized by disrupted TGF-ß signaling. We recently identified two novel protein O-glucosyltransferases, Protein O-glucosyltransferase 2 (POGLUT2) and 3 (POGLUT3), that modify a small fraction of EGF repeats on Notch. Here, using mass spectral analysis, we show that POGLUT2 and POGLUT3 also modify over half of the EGF repeats on FBN1, fibrillin-2 (FBN2), and LTBP1. While most sites are modified by both enzymes, some sites show a preference for either POGLUT2 or POGLUT3. POGLUT2 and POGLUT3 are homologs of POGLUT1, which stabilizes Notch proteins by addition of O-glucose to Notch EGF repeats. Like POGLUT1, POGLUT2 and 3 can discern a folded versus unfolded EGF repeat, suggesting POGLUT2 and 3 are involved in a protein folding pathway. In vitro secretion assays using the N-terminal portion of recombinant FBN1 revealed reduced FBN1 secretion in POGLUT2 knockout, POGLUT3 knockout, and POGLUT2 and 3 double-knockout HEK293T cells compared with wild type. These results illustrate that POGLUT2 and 3 function together to O-glucosylate protein substrates and that these modifications play a role in the secretion of substrate proteins. It will be interesting to see how disease variants in these proteins affect their O-glucosylation.


Subject(s)
Fibrillin-1/metabolism , Fibrillin-2/metabolism , Latent TGF-beta Binding Proteins/metabolism , Marfan Syndrome/metabolism , Amino Acid Motifs , Fibrillin-1/chemistry , Fibrillin-1/genetics , Fibrillin-2/chemistry , Fibrillin-2/genetics , Glycosylation , Humans , Latent TGF-beta Binding Proteins/chemistry , Latent TGF-beta Binding Proteins/genetics , Marfan Syndrome/enzymology , Marfan Syndrome/genetics , Protein Translocation Systems , Signal Transduction
6.
J Biol Chem ; 297(1): 100843, 2021 07.
Article in English | MEDLINE | ID: mdl-34058199

ABSTRACT

Peters Plus Syndrome (PTRPLS OMIM #261540) is a severe congenital disorder of glycosylation where patients have multiple structural anomalies, including Peters anomaly of the eye (anterior segment dysgenesis), disproportionate short stature, brachydactyly, dysmorphic facial features, developmental delay, and variable additional abnormalities. PTRPLS patients and some Peters Plus-like (PTRPLS-like) patients (who only have a subset of PTRPLS phenotypes) have mutations in the gene encoding ß1,3-glucosyltransferase (B3GLCT). B3GLCT catalyzes the transfer of glucose to O-linked fucose on thrombospondin type-1 repeats. Most B3GLCT substrate proteins belong to the ADAMTS superfamily and play critical roles in extracellular matrix. We sought to determine whether the PTRPLS or PTRPLS-like mutations abrogated B3GLCT activity. B3GLCT has two putative active sites, one in the N-terminal region and the other in the C-terminal glycosyltransferase domain. Using sequence analysis and in vitro activity assays, we demonstrated that the C-terminal domain catalyzes transfer of glucose to O-linked fucose. We also generated a homology model of B3GLCT and identified D421 as the catalytic base. PTRPLS and PTRPLS-like mutations were individually introduced into B3GLCT, and the mutated enzymes were evaluated using in vitro enzyme assays and cell-based functional assays. Our results demonstrated that PTRPLS mutations caused loss of B3GLCT enzymatic activity and/or significantly reduced protein stability. In contrast, B3GLCT with PTRPLS-like mutations retained enzymatic activity, although some showed a minor destabilizing effect. Overall, our data supports the hypothesis that loss of glucose from B3GLCT substrate proteins is responsible for the defects observed in PTRPLS patients, but not for those observed in PTRPLS-like patients.


Subject(s)
Cleft Lip/enzymology , Cleft Lip/genetics , Cornea/abnormalities , Galactosyltransferases/genetics , Galactosyltransferases/metabolism , Glucosyltransferases/genetics , Glucosyltransferases/metabolism , Growth Disorders/enzymology , Growth Disorders/genetics , Limb Deformities, Congenital/enzymology , Limb Deformities, Congenital/genetics , Mutation/genetics , ADAMTS Proteins/metabolism , Amino Acid Motifs , Amino Acid Sequence , Biocatalysis , Cornea/enzymology , Enzyme Stability , Fucose/metabolism , Galactosyltransferases/chemistry , Glucose/metabolism , Glucosyltransferases/chemistry , HEK293 Cells , Humans , Kinetics , Models, Molecular , Protein Domains , Repetitive Sequences, Amino Acid , Structural Homology, Protein
7.
J Biol Chem ; 295(43): 14710-14722, 2020 10 23.
Article in English | MEDLINE | ID: mdl-32820046

ABSTRACT

Notch signaling is a cellular pathway regulating cell-fate determination and adult tissue homeostasis. Little is known about how canonical Notch ligands or Fringe enzymes differentially affect NOTCH1 and NOTCH2. Using cell-based Notch signaling and ligand-binding assays, we evaluated differences in NOTCH1 and NOTCH2 responses to Delta-like (DLL) and Jagged (JAG) family members and the extent to which Fringe enzymes modulate their activity. In the absence of Fringes, DLL4-NOTCH1 activation was more than twice that of DLL4-NOTCH2, whereas all other ligands activated NOTCH2 similarly or slightly more than NOTCH1. However, NOTCH2 showed less sensitivity to the Fringes. Lunatic fringe (LFNG) enhanced NOTCH2 activation by DLL1 and -4, and Manic fringe (MFNG) inhibited NOTCH2 activation by JAG1 and -2. Mass spectral analysis showed that O-fucose occurred at high stoichiometry at most consensus sequences of NOTCH2 and that the Fringe enzymes modified more O-fucose sites of NOTCH2 compared with NOTCH1. Mutagenesis studies showed that LFNG modification of O-fucose on EGF8 and -12 of NOTCH2 was responsible for enhancement of DLL1-NOTCH2 activation, similar to previous reports for NOTCH1. In contrast to NOTCH1, a single O-fucose site mutant that substantially blocked the ability of MFNG to inhibit NOTCH2 activation by JAG1 could not be identified. Interestingly, elimination of the O-fucose site on EGF12 allowed LFNG to inhibit JAG1-NOTCH2 activation, and O-fucosylation on EGF9 was important for trafficking of both NOTCH1 and NOTCH2. Together, these studies provide new insights into the differential regulation of NOTCH1 and NOTCH2 by Notch ligands and Fringe enzymes.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Calcium-Binding Proteins/metabolism , Receptor, Notch1/metabolism , Receptor, Notch2/metabolism , Animals , CHO Cells , Cricetulus , HEK293 Cells , Humans , Ligands , Mice , NIH 3T3 Cells
8.
Glycobiology ; 31(8): 988-1004, 2021 09 09.
Article in English | MEDLINE | ID: mdl-33909046

ABSTRACT

Peters plus syndrome, characterized by defects in eye and skeletal development with isolated cases of ventriculomegaly/hydrocephalus, is caused by mutations in the ß3-glucosyltransferase (B3GLCT) gene. In the endoplasmic reticulum, B3GLCT adds glucose to O-linked fucose on properly folded thrombospondin type 1 repeats (TSRs). The resulting glucose-fucose disaccharide is proposed to stabilize the TSR fold and promote secretion of B3GLCT substrates, with some substrates more sensitive than others to loss of glucose. Mouse B3glct mutants develop hydrocephalus at high frequency. In this study, we demonstrated that B3glct mutant ependymal cells had fewer cilia basal bodies and altered translational polarity compared to controls. Localization of mRNA encoding A Disintegrin and Metalloproteinase with ThromboSpondin type 1 repeat 20 (ADAMTS20) and ADAMTS9 suggested that reduced function of these B3GLCT substrates contributed to ependymal cell abnormalities. In addition, we showed that multiple B3GLCT substrates (Adamts3, Adamts9 and Adamts20) are expressed by the subcommissural organ, that subcommissural organ-spondin ((SSPO) also known as SCO-spondin) TSRs were modified with O-linked glucose-fucose and that loss of B3GLCT reduced secretion of SSPO in cultured cells. In the B3glct mutant, intracellular levels of SSPO were reduced and BiP levels increased, suggesting a folding defect. Secreted SSPO colocalized with BiP, raising the possibility that abnormal extracellular assembly of SSPO into Reissner's fiber also contributed to impaired CSF flow in mutants. Combined, these studies underscore the complexity of the B3glct mutant hydrocephalus phenotype and demonstrate that impaired cerebrospinal fluid (CSF) flow likely stems from the collective effects of the mutation on multiple processes.


Subject(s)
Hydrocephalus , Limb Deformities, Congenital , Subcommissural Organ , Animals , Glucosyltransferases/genetics , Glycosyltransferases , Growth Disorders/genetics , Hydrocephalus/genetics , Limb Deformities, Congenital/genetics , Mice , Subcommissural Organ/metabolism
9.
Glycobiology ; 31(5): 582-592, 2021 06 03.
Article in English | MEDLINE | ID: mdl-33351914

ABSTRACT

Successful hematopoietic progenitor cell (HPC) transplant therapy is improved by mobilizing HPCs from the bone marrow niche in donors. Notch receptor-ligand interactions are known to retain HPCs in the bone marrow, and neutralizing antibodies against Notch ligands, Jagged-1 or Delta-like ligand (DLL4), or NOTCH2 receptor potentiates HPC mobilization. Notch-ligand interactions are dependent on posttranslational modification of Notch receptors with O-fucose and are modulated by Fringe-mediated extension of O-fucose moieties. We previously reported that O-fucosylglycans on Notch are required for Notch receptor-ligand engagement controlling hematopoietic stem cell quiescence and retention in the marrow niche. Here, we generated recombinant fragments of NOTCH1 or NOTCH2 extracellular domain carrying the core ligand-binding regions (EGF11-13) either as unmodified forms or as O-fucosylglycan-modified forms. We found that the addition of O-fucose monosaccharide or the Fringe-extended forms of O-fucose to EGF11-13 showed substantial increases in binding to DLL4. Furthermore, the O-fucose and Fringe-extended NOTCH1 EGF11-13 protein displayed much stronger binding to DLL4 than the NOTCH2 counterpart. When assessed in an in vitro 3D osteoblastic niche model, we showed that the Fringe-extended NOTCH1 EGF11-13 fragment effectively released lodged HPC cells with a higher potency than the NOTCH2 blocking antibody. We concluded that O-fucose and Fringe-modified NOTCH1 EGF11-13 protein can be utilized as effective decoys for stem cell niche localized ligands to potentiate HPC egress and improve HPC collection for hematopoietic cell therapy.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Calcium-Binding Proteins/metabolism , Fucose/metabolism , Hematopoietic Stem Cells/metabolism , Receptor, Notch1/metabolism , Receptor, Notch2/metabolism , Animals , CHO Cells , Cricetulus , HEK293 Cells , Humans , Receptor, Notch1/genetics , Receptor, Notch2/genetics
10.
Parasitology ; 148(13): 1636-1647, 2021 11.
Article in English | MEDLINE | ID: mdl-34311794

ABSTRACT

The taxonomy of ruminant Trypanosoma theileri and its relatives (Kinetoplastida: Trypanosomatidae) is controversial, with recent phylogenetic studies segregating T. theileri in cattle and other ruminants worldwide into two major genetic lineages (the TthI and TthII clades) based on genetic markers. In the present study, T. theileri-like trypanosomes isolated from Honshu sika deer (Cervus nippon) in the western Japan (YMG isolate) were genetically characterized using a number of genetic markers. Sika deer trypanosomes of the YMG isolate were genetically different from the Trypanosoma sp. TSD1 isolate previously recorded from Hokkaido sika deer in northern Japan, with the former trypanosome isolate being genetically closer to European cervid trypanosomes and the bovine T. theileri TthII lineage. In contrast, the latter isolate exhibited greater relatedness to North American cervid trypanosomes and the bovine T. theileri TthI lineage, although a clear genetic distinction between these was apparent. Furthermore, trypanosomes in Honshu sika deer from the central part of Japan harboured additional genetic diversity and were closer to either TSD1 or YMG isolates, while distinct from known T. theileri-related genotypes. Importantly, cervids and wild ruminants worldwide might harbour divergent descendants of a T. theileri ancestor, which exhibit rigid host specificity to either bovines or cervid species.


Subject(s)
Deer , Trypanosoma , Animals , Cattle , Genetic Variation , Japan/epidemiology , Phylogeny , Trypanosoma/genetics
11.
Proc Natl Acad Sci U S A ; 115(36): E8395-E8402, 2018 09 04.
Article in English | MEDLINE | ID: mdl-30127001

ABSTRACT

The Notch-signaling pathway is normally activated by Notch-ligand interactions. A recent structural analysis suggested that a novel O-linked hexose modification on serine 435 of the mammalian NOTCH1 core ligand-binding domain lies at the interface with its ligands. This serine occurs between conserved cysteines 3 and 4 of Epidermal Growth Factor-like (EGF) repeat 11 of NOTCH1, a site distinct from those modified by protein O-glucosyltransferase 1 (POGLUT1), suggesting that a different enzyme is responsible. Here, we identify two novel protein O-glucosyltransferases, POGLUT2 and POGLUT3 (formerly KDELC1 and KDELC2, respectively), which transfer O-glucose (O-Glc) from UDP-Glc to serine 435. Mass spectrometric analysis of NOTCH1 produced in HEK293T cells lacking POGLUT2, POGLUT3, or both genes showed that either POGLUT2 or POGLUT3 can add this novel O-Glc modification. EGF11 of NOTCH2 does not have a serine residue in the same location for this O-glucosylation, but EGF10 of NOTCH3 (homologous to EGF11 in NOTCH1 and -2) is also modified at the same position. Comparison of the sites suggests a consensus sequence for modification. In vitro assays with POGLUT2 and POGLUT3 showed that both enzymes modified only properly folded EGF repeats and displayed distinct acceptor specificities toward NOTCH1 EGF11 and NOTCH3 EGF10. Mutation of the O-Glc modification site on EGF11 (serine 435) in combination with sensitizing O-fucose mutations in EGF8 or EGF12 affected cell-surface presentation of NOTCH1 or reduced activation of NOTCH1 by Delta-like1, respectively. This study identifies a previously undescribed mechanism for fine-tuning the Notch-signaling pathway in mammals.


Subject(s)
Glucosyltransferases/metabolism , Receptor, Notch1/metabolism , Receptor, Notch2/metabolism , Receptor, Notch3/metabolism , Signal Transduction/physiology , Animals , Glucosyltransferases/genetics , Glycosylation , HEK293 Cells , Humans , Mice , NIH 3T3 Cells , Protein Transport/physiology , Receptor, Notch1/genetics , Receptor, Notch2/genetics , Receptor, Notch3/genetics , Repetitive Sequences, Amino Acid
12.
Parasitol Res ; 118(1): 97-109, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30353232

ABSTRACT

Trypanosoma lewisi (Kinetoplastea: Trypanosomatida: Trypanosomatidae) with a cosmopolitan distribution is the type species of the subgenus Herpetosoma, which includes ca. 50 nominal species isolated mainly from rodents. Since members of Herpetosoma in different host species have an almost identical morphology of bloodstream forms, these trypanosomes are referred to as 'T. lewisi-like', and the molecular genetic characterization of each species is necessary to verify their taxonomy. In the present study, we collected blood samples from 89 murid rodents of 15 species and 11 soricids of four species in Indonesia, Philippines, Vietnam, Taiwan, and mainland China for the detection of hemoprotozoan infection. T. lewisi and T. lewisi-like trypanosomes were found in the blood smears of 10 murid animals, which included Bandicota indica (two rats), Rattus argentiventer (one rat), and Rattus tiomanicus (two rats) in Indonesia; Rattus rattus (one rat) in the Philippines; and Niviventer confucianus (four rats) in mainland China. Furthermore, large- or medium-sized non-T. lewisi-like trypanosomes were detected in two soricids, Crocidura dracula in Vietnam and Anourosorex yamashinai in Taiwan, respectively. Molecular genetic characterization of the small subunit (SSU) ribosomal RNA gene (rDNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene indicated that the trypanosomes from all the murid hosts had identical SSU rDNA or gGAPDH gene nucleotide sequences except for those in N. confucianus in mainland China. These N. confucianus-infecting trypanosomes also showed several unique morphological features such as smaller bodies, anteriorly positioned nuclei, and larger rod-shaped kinetoplasts when compared with T. lewisi trypomastigotes. Trypanosoma (Herpetosoma) niviventerae n. sp. is erected for this new species. Similarly, based on morphological and molecular genetic characterization, Trypanosoma sapaensis n. sp. and Trypanosoma anourosoricis n. sp. are proposed for the trypanosomes in C. dracula in Vietnam and A. yamashinai in Taiwan, respectively. More effort directed toward the morphological and molecular genetic characterization of the trypanosomes of rodents and soricids is required to fully understand the real biodiversity of their hemoflagellates.


Subject(s)
Murinae/parasitology , Rats/parasitology , Rodent Diseases/parasitology , Trypanosoma/classification , Trypanosomiasis/veterinary , Animals , Asia, Southeastern/epidemiology , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Asia, Eastern/epidemiology , Glyceraldehyde-3-Phosphate Dehydrogenases/genetics , Phylogeny , Protozoan Proteins/genetics , Rodent Diseases/blood , Rodent Diseases/epidemiology , Sequence Analysis, DNA/veterinary , Trypanosoma/cytology , Trypanosoma/genetics , Trypanosoma/isolation & purification , Trypanosoma lewisi/genetics , Trypanosoma lewisi/isolation & purification , Trypanosomiasis/epidemiology , Trypanosomiasis/parasitology
13.
J Biol Chem ; 292(38): 15964-15973, 2017 09 22.
Article in English | MEDLINE | ID: mdl-28729422

ABSTRACT

Glycosylation in the endoplasmic reticulum (ER) is closely associated with protein folding and quality control. We recently described a non-canonical ER quality control mechanism for folding of thrombospondin type 1 repeats by protein O-fucosyltransferase 2 (POFUT2). Epidermal growth factor-like (EGF) repeats are also small cysteine-rich protein motifs that can be O-glycosylated by several ER-localized enzymes, including protein O-glucosyltransferase 1 (POGLUT1) and POFUT1. Both POGLUT1 and POFUT1 modify the Notch receptor on multiple EGF repeats and are essential for full Notch function. The fact that POGLUT1 and POFUT1 can distinguish between folded and unfolded EGF repeats raised the possibility that they participate in a quality control pathway for folding of EGF repeats in proteins such as Notch. Here, we demonstrate that cell-surface expression of endogenous Notch1 in HEK293T cells is dependent on the presence of POGLUT1 and POFUT1 in an additive manner. In vitro unfolding assays reveal that addition of O-glucose or O-fucose stabilizes a single EGF repeat and that addition of both O-glucose and O-fucose enhances stability in an additive manner. Finally, we solved the crystal structure of a single EGF repeat covalently modified by a full O-glucose trisaccharide at 2.2 Å resolution. The structure reveals that the glycan fills up a surface groove of the EGF with multiple contacts with the protein, providing a chemical basis for the stabilizing effects of the glycans. Taken together, this work suggests that O-fucose and O-glucose glycans cooperatively stabilize individual EGF repeats through intramolecular interactions, thereby regulating Notch trafficking in cells.


Subject(s)
Epidermal Growth Factor/chemistry , Oxygen/metabolism , Receptors, Notch/chemistry , Receptors, Notch/metabolism , Repetitive Sequences, Amino Acid , Amino Acid Sequence , Animals , Fucosyltransferases/deficiency , Fucosyltransferases/genetics , Gene Expression Regulation , Gene Knockout Techniques , Glucose/metabolism , Glucosyltransferases/deficiency , Glucosyltransferases/genetics , Glycosylation , HEK293 Cells , Humans , Mice , Models, Molecular , Protein Conformation , Protein Transport , Receptor, Notch1/chemistry , Receptor, Notch1/metabolism
14.
Glycobiology ; 28(5): 276-283, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29452367

ABSTRACT

Protein O-fucosyltransferase-1 (POFUT1) adds O-fucose monosaccharides to epidermal growth factor-like (EGF) repeats found on approximately 100 mammalian proteins, including Notch receptors. Haploinsufficiency of POFUT1 has been linked to adult-onset Dowling Degos Disease (DDD) with hyperpigmentation defects. Homozygous deletion of mouse Pofut1 results in embryonic lethality with severe Notch-like phenotypes including defects in somitogenesis, cardiogenesis, vasculogenesis and neurogenesis, but the extent to which POFUT1 is required for normal human development is not yet understood. Here we report a patient with a congenital syndrome consisting of severe global developmental delay, microcephaly, heart defects, failure to thrive and liver disease with a previously unreported homozygous NM_015352.1: c.485C>T variant (p.Ser162Leu) in POFUT1 detected by exome sequencing. Both parents are heterozygotes and neither manifests any signs of DDD. No other detected variant explained the phenotype. This variant eliminated a conserved N-glycosylation sequon at Asn160 in POFUT1 and profoundly decreased POFUT1 activity in patient fibroblasts compared to control fibroblasts. Purified p.Ser162Leu mutant protein also showed much lower POFUT1 activity with a lower affinity for EGF acceptor substrate than wild type POFUT1. Eliminating the N-glycan sequon by replacing Asn160 with Gln had little effect on POFUT1 activity, suggesting that loss of the glycan is not responsible for the defect. Furthermore, the p.Ser162Leu mutant showed weaker ability to rescue Notch activity in cell-based assays. These results suggest that this N-glycan of POFUT1 is not required for its proper enzymatic function, and that the p.Ser162Leu mutation of POFUT1 likely causes global developmental delay, microcephaly with vascular and cardiac defects.


Subject(s)
Cardiovascular Diseases/genetics , Developmental Disabilities/genetics , Fucosyltransferases/genetics , Fucosyltransferases/metabolism , Genetic Variation/genetics , Microcephaly/genetics , Cells, Cultured , HEK293 Cells , Humans , Mutation
15.
Int J Parasitol Parasites Wildl ; 25: 100975, 2024 Dec.
Article in English | MEDLINE | ID: mdl-39297148

ABSTRACT

We investigated intraerythrocytic Babesia parasites in 21 Japanese wild boars, Sus scrofa leucomystax, captured in Wakayama Prefecture on the mainland from 2008 to 2009 and in 31 Japanese wild boars from 2011 to 2013 in Kochi Prefecture on Shikoku Island, Japan. We detected small subunit ribosomal RNA (18S rRNA) gene (SSUrDNA) fragments of a Babesia species in 17 boars from Wakayama and 18 boars from Kochi. The nearly full SSUrDNA sequence (1669 bps) of this species was determined. A FASTA search revealed that the SSUrDNA sequence of the Babesia sp. in Japanese wild boars was the most homologous to those of several Babesia isolates reported as Babesia gibsoni. Phylogenetic analysis showed that the Babesia sp. found in Japanese wild boars was the closest relative to B. gibsoni but made a different clade from B. gibsoni. The Babesia sp. in Japanese wild boars was completely different from Babesia sp. Suis found in a European domestic pig, Sus scrofa domesticus. By microscopic examination, ring-shaped, oval and pear-shaped small sized intraerythrocytic parasites were observed on blood smears of 12 of 18 Japanese wild boars whose blood smears could be examined in Wakayama. We also detected SSUrDNA fragments of a Hepatozoon species in 6 of the 21 wild boars from Wakayama. The nearly full SSUrDNA sequence (1774 bps) of the Hepatozoon sp. was shown to be identical to that of Hepatozoon apri.

16.
Ann Palliat Med ; 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-39129525

ABSTRACT

BACKGROUND: Hospital-based specialized palliative care teams (HSPC) are important for symptom management and ethics support, especially during complex decision-making, but the needs of patients with noncancer diseases and their families from the HSPC are unclear. This study aimed to (I) compare the prevalence of symptom between patients with and without cancer and explore changes in symptom intensity after HSPC consultation in patients with noncancer; (II) determine factors related to ethics support; and (III) compare the percentage of request contents from patients and their families when a certified nurse specialist in gerontological nursing (geriatric care nurse below) is present in the HSPC to that when a certified nurse specialist in palliative care (palliative care nurse below) is present in the HSPC. METHODS: We utilized a retrospective cohort study to analyze 761 patients (360 with noncancer and 401 with cancer) referred to our HSPC at the National Center for Geriatrics and Gerontology using 10-year data (since 2011) available in an electronic medical record database. (I) Symptom scores of the Support Team Assessment Schedule were compared between noncancer and cancer groups and between initial and 1-week assessments for noncancer patients. (II) Ethics support was compared between noncancer (including dementia) and cancer. The presence or absence of ethics support requests, which was set as the objective variable, was examined using logistic regression analysis. (III) The percentage of request contents selected from nine items defaulted on the electronic medical record when a geriatric care nurse was present in our HSPC were compared to those when a palliative care nurse was present in our HSPC. RESULTS: Compared to those with cancer, patients with noncancer suffered more from dyspnea and sputum accumulation. More than 10% of patients with noncancer had suffered from pain, dyspnea, sputum accumulation, and anorexia that required treatment, with symptom scores showing improvement after 1 week of HSPC involvement, except for the sputum accumulation. Moreover, for anorexia, symptom scores improved, but >10% of these patients continued to suffer. Patients with noncancer diseases, including dementia, received ethics support than those with cancer without dementia. More requests for ethics support were received when a geriatric care nurse was in the HSPC than when a palliative care nurse was in the HSPC. Logistic regression analysis revealed that requests for ethics support were more frequent from patients or families with impaired decision-making capacity or when the patient lacked an advocate. CONCLUSIONS: The needs of patients with noncancer diseases and families from the HSPC in Japan included (I) symptom management for intractable conditions, such as sputum accumulation; (II) ethics support for patients with noncancer diseases, including dementia, with impaired decision-making capacity, and without advocates; and (III) advice on ethics issues from a geriatric care nurse.

17.
Psychooncology ; 22(9): 2140-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23436588

ABSTRACT

OBJECTIVES: This study examined both the frequency of appearance-related symptoms and distress resulting from these symptoms in cancer patients receiving chemotherapy. METHODS: Self-report questionnaires were distributed to 753 outpatients receiving ≧ 4 weeks of treatment at an outpatient chemotherapy center. Valid responses were returned by 638 patients (response rate, 84.7%). Participants were questioned about 57 appearance-related symptoms (AS) and 23 non-appearance-related physical symptoms (non-AS); psychological well-being was assessed using a shortened version of the Derriford Appearance Scale 59. RESULTS: Questionnaire responses were obtained from 264 male and 374 female patients (mean age, 59.5 years; range, 18-85 years). Most respondents (80.3%) were concerned with changes in appearance resulting from treatment. By sex and disease type, women suffered more than men, and treatment for breast cancer created the greatest distress for women. CONCLUSION: Cancer patients are concerned about a variety of AS, and these may result in greater distress than non-AS. AS-related information and care are increasingly being sought in advance of treatment.


Subject(s)
Body Image/psychology , Neoplasms/psychology , Stress, Psychological/psychology , Adolescent , Adult , Aged , Aged, 80 and over , Alopecia/chemically induced , Alopecia/psychology , Antineoplastic Agents/adverse effects , Breast Neoplasms/psychology , Cicatrix/psychology , Female , Humans , Male , Mastectomy/psychology , Middle Aged , Quality of Life , Sex Factors , Surveys and Questionnaires , Young Adult
18.
Matrix Biol ; 107: 77-96, 2022 03.
Article in English | MEDLINE | ID: mdl-35167946

ABSTRACT

Many extracellular matrix (ECM) associated proteins that influence ECM properties have Thrombospondin type 1 repeats (TSRs) which are modified with O-linked fucose. The O-fucose is added in the endoplasmic reticulum to folded TSRs by the enzyme Protein O-fucosyltransferase-2 (POFUT2) and is proposed to promote efficient trafficking of substrates. The importance of this modification for function of TSR-proteins is underscored by the early embryonic lethality of mouse embryos lacking Pofut2. To overcome early lethality and investigate the impact of the Pofut2 knockout on the secretion of POFUT2 substrates and on extracellular matrix properties in vivo, we deleted Pofut2 in the developing limb mesenchyme using Prrx1-Cre recombinase. Loss of Pofut2 in the limb mesenchyme caused significant shortening of the limbs, long bones and tendons and stiff joint resembling the musculoskeletal dysplasias in human and in mice with mutations in ADAMTS or ADAMTSL proteins. Limb shortening was evident at embryonic day 14.5 where loss of O-fucosylation led to an accumulation of fibrillin 2 (FBN2), decreased BMP and IHH signaling, and increased TGF-ß signaling. Consistent with these changes we saw a decrease in the size of the hypertrophic zone with lower levels of Collagen-X. Unexpectedly, we observed minimal effects of the Pofut2 knockout on secretion of two POFUT2 substrates, CCN2 or ADAMTS17, in the developing bone. In contrast, CCN2 and two other POFUT2 substrates important for bone development, ADAMTS6 and 10, showed a decrease in secretion from POFUT2-null HEK293T cells in vitro. These combined results suggest that the impact of the Pofut2 mutation is cell-type specific. In addition, these observations raise the possibility that the O-fucose modification on TSRs extends beyond promoting efficient trafficking of POFUT2 substrates and has the potential to influence their function in the extracellular environment.


Subject(s)
Fucosyltransferases , Thrombospondins , Animals , Bone Development , Extracellular Matrix/metabolism , Fucosyltransferases/chemistry , Fucosyltransferases/genetics , Fucosyltransferases/metabolism , HEK293 Cells , Homeodomain Proteins , Humans , Mice
19.
Jpn J Infect Dis ; 73(4): 288-292, 2020 07 22.
Article in English | MEDLINE | ID: mdl-32115542

ABSTRACT

A 5-year multicenter retrospective cohort study was conducted across six hospitals in Niigata, Japan. Patients (n = 179) with bacteremia due to extended-spectrum ß-lactamase (ESBL)producing organisms were included in the study. The rates of appropriate carbapenem prescription were 61% (n = 41) in patients aged 65-84 years and 89% (n = 31) in those aged ≥ 85 years. Patients aged ≥ 85 years were significantly more likely to receive carbapenem than their younger counterparts. After propensity score matching, 65 patients were assigned to two groups based on age (65-84 years or ≥ 85 years). Multivariate regression analysis showed that other sites of infection had a positive association with 30-day mortality (odds ratio [OR], 27.50; 95% confidence interval [CI], 2.90-260.00) and biliary tract infection tended to have a positive association with 30-day mortality (OR, 8.90; 95% CI, 0.88- 89.90) compared with urinary tract infection. However, an age ≥ 85 years was not associated with 30-day mortality. Elderly patients aged ≥ 85 years were more likely to be treated with carbapenem; however, old age was not associated with 30-day mortality when bacteremia was caused by ESBLproducing organisms. These results may help clinicians justify withholding carbapenem in patients aged ≥ 85 years.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteremia/drug therapy , Bacteremia/microbiology , Carbapenems/therapeutic use , Age Distribution , Aged , Aged, 80 and over , Bacteremia/mortality , Cohort Studies , Comorbidity , Female , Humans , Japan/epidemiology , Male , Retrospective Studies , Risk Factors , beta-Lactamases/metabolism
20.
BMC Evol Biol ; 9: 233, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19751533

ABSTRACT

BACKGROUND: In mammals, pheromones play an important role in social and innate reproductive behavior within species. In rodents, vomeronasal receptor type 1 (V1R), which is specifically expressed in the vomeronasal organ, is thought to detect pheromones. The V1R gene repertoire differs dramatically between mammalian species, and the presence of species-specific V1R subfamilies in mouse and rat suggests that V1R plays a profound role in species-specific recognition of pheromones. In ruminants, however, the molecular mechanism(s) for pheromone perception is not well understood. Interestingly, goat male pheromone, which can induce out-of-season ovulation in anestrous females, causes the same pheromone response in sheep, and vice versa, suggesting that there may be mechanisms for detecting "inter-species" pheromones among ruminant species. RESULTS: We isolated 23 goat and 21 sheep intact V1R genes based on sequence similarity with 32 cow V1R genes in the cow genome database. We found that all of the goat and sheep V1R genes have orthologs in their cross-species counterparts among these three ruminant species and that the sequence identity of V1R orthologous pairs among these ruminants is much higher than that of mouse-rat V1R orthologous pairs. Furthermore, all goat V1Rs examined thus far are expressed not only in the vomeronasal organ but also in the main olfactory epithelium. CONCLUSION: Our results suggest that, compared with rodents, the repertoire of orthologous V1R genes is remarkably conserved among the ruminants cow, sheep and goat. We predict that these orthologous V1Rs can detect the same or closely related chemical compound(s) within each orthologous set/pair. Furthermore, all identified goat V1Rs are expressed in the vomeronasal organ and the main olfactory epithelium, suggesting that V1R-mediated ligand information can be detected and processed by both the main and accessory olfactory systems. The fact that ruminant and rodent V1Rs have distinct features suggests that ruminant and rodent V1Rs have evolved distinct functions.


Subject(s)
Goats/genetics , Receptors, Odorant/genetics , Sheep/genetics , Animals , Cattle/genetics , Conserved Sequence/genetics , Mice , Olfactory Mucosa/metabolism , Phylogeny , Rats , Sequence Analysis, DNA , Species Specificity , Vomeronasal Organ/metabolism
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