A5073160537- Glycosylation and Glycoproteins Research
- Carbohydrate Chemistry and Synthesis
- Galectins and Cancer Biology
- Cellular transport and secretion
- Monoclonal and Polyclonal Antibodies Research
- Infant Nutrition and Health
- Adipokines, Inflammation, and Metabolic Diseases
- Pancreatic function and diabetes
- Adipose Tissue and Metabolism
- Digestive system and related health
- Enzyme Production and Characterization
- Amino Acid Enzymes and Metabolism
- Lysosomal Storage Disorders Research
- Polyamine Metabolism and Applications
- Erythrocyte Function and Pathophysiology
- Drug Transport and Resistance Mechanisms
- Lipid Membrane Structure and Behavior
- Proteoglycans and glycosaminoglycans research
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Animal Genetics and Reproduction
- Diet and metabolism studies
- Viral Infectious Diseases and Gene Expression in Insects
- Retinal Development and Disorders
- Microbial Metabolic Engineering and Bioproduction
- Enzyme Structure and Function
Université Claude Bernard Lyon 1
2010-2025
Centre National de la Recherche Scientifique
2021-2025
VetAgro Sup
2021-2025
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2021-2024
Ecologie Microbienne Lyon
2021-2022
Inserm
2010-2021
Laboratoire CarMeN
2012-2021
Hospices Civils de Lyon
2010-2019
Centre Hospitalier Universitaire de Besançon
2007-2018
Institut National des Sciences Appliquées de Lyon
2014-2017
An affinity-purified, monospecific rabbit antibody against soluble human milk galactosyltransferase was used to localize the enzyme in HeLa cells by immunofluorescence and protein A-gold technique at electron microscope level. Specific observed a juxtanuclear cytoplasmic region which identified, on immunostained thin sections of low-temperature Lowicryl K4M-embedded cells, as Golgi apparatus. Label gold particles limited two three trans cisternae apparatus, indicating compartmentalization...
The distribution of beta 1,2 N-acetylglucosaminyltransferase I (NAGT I), alpha 1,3-1,6 mannosidase II (Mann II), 1,4 galactosyltransferase (GalT), 2,6 sialyltransferase (SialylT) was determined by immuno-labelling cryo-sections from HeLa cell lines. Antibody labelling in the line made possible stable expression epitope-tagged forms these proteins or species to which specific antibodies were available. NAGT and Mann had same occupying medial trans cisternae stack. GalT SialylT also but they...
Immunoelectron microscopy and stereology were used to identify quantitate Golgi fragments in metaphase HeLa cells study reassembly during telophase. On ultrathin frozen sections of cells, labeling for the marker protein, galactosyltransferase, was found over multivesicular clusters free vesicles that mainly mitotic spindle region. The density cluster membrane varied from cell inversely related spindle. There thousands they comprised a significant proportion total membrane. During telophase,...
ABSTRACT O-glycosylation of proteins is initiated by a family UDP-N-acetylgalactosamine:polypeptide N-acetylgalactos-aminyltransferases (GalNAc-T). In this study, we have localized endogenous and epitope-tagged human GalNAc-T1, -T2 -T3 to the Golgi apparatus in HeLa cells subcellular fractionation, immunofluorescence immunoelectron microscopy. We show that all three GalNAc-transferases are concentrated about tenfold stacks over associated tubular-vesicular membrane structures. Surprisingly,...
Thin, frozen sections of a HeLa cell line were double labeled with specific antibodies to localize the trans-Golgi enzyme, beta 1,4 galactosyltransferase (GalT) and medial N-acetylglucosaminyltransferase I (NAGT I). The latter was detected by generating stably expressing myc-tagged version endogenous protein. GalT found in trans-cisterna network but, contrary expectation, NAGT both medial- trans-cisternae, overlapping distribution GalT. About one third half shared, trans-cisterna. These data...
Procollagen (PC)-I aggregates transit through the Golgi complex without leaving lumen of cisternae. Based on this evidence, we have proposed that PC-I is transported across stacks by cisternal maturation process. However, most secretory cargoes are small, freely diffusing proteins, thus raising issue whether they move a transport mechanism different than used PC-I. To address question developed procedures to compare small protein, G protein vesicular stomatitis virus (VSVG), with much larger...
Exosomes are nanometer-sized microvesicles formed in multivesicular bodies (MVBs) during endosome maturation. released from cells into the microenvironment following fusion of MVBs with plasma membrane. During last decade, skeletal muscle-secreted proteins have been identified important roles intercellular communications. To investigate whether muscle-derived exosomes participate this molecular dialog, we determined and compared protein contents exosome-like vesicles (ELVs) C2C12 murine...
We have determined whether orange juice-derived nanovesicles (ONVs) could be used for the treatment of obesity-associated intestinal complications. ONVs were characterized by lipidomic, metabolomic, electron microscopy. In vitro, barriers (IBs = Caco-2+HT-29-MTX) treated with and co-cultured adipocytes to monitor IB fat release. vivo, obesity was induced a high-fat, high-sucrose diet (HFHSD mice) 12 weeks. Then, half HFHSD mice gavaged ONVs. One-month ONV did not modify HFHSD-induced insulin...
Adipose tissue hypertrophy during obesity plays pleiotropic effects on health. expandability depends adipocyte size and number. In mature adipocytes, lipid accumulation as triglycerides into droplets is imbalanced by uptake lipolysis. previous studies, we showed that adipogenesis induced oleic acid signed increase reduction of FAT/CD36 (SR-B2) activity. The present study aims to decipher the mechanisms involved in fat mass regulation fatty acid/FAT-CD36 signalling. Human adipose stem cells,...
Congenital disorders of glycosylation (CDG), formerly known as carbohydrate-deficient glycoprotein syndromes, lead to diseases with variable clinical pictures. We report the delineation a novel type CDG identified in 2 children presenting severe developmental delay, seizures, and dysmorphic features. detected hypoglycosylation on serum transferrin cerebrospinal fluid beta-trace protein. Lipid-linked oligosaccharides endoplasmic reticulum patient fibroblasts showed an accumulation dolichyl...
rab6 is a ubiquitous ras-like GTPase involved in intra-Golgi transport. We have studied at both morphological and biochemical levels the behavior of Golgi resident proteins HeLa cells overexpressing wild-type GTP- GDP-bound mutants (rab6 Q72L T27N, respectively). show that overexpression induces redistribution trans-Golgi protein β-1,4-galactosyltransferase into endoplasmic reticulum (ER) allows addition sialylated O-glycans on an ER-retained protein, major histocompatibility complex class...
Deficiencies in the pathway of N-glycan biosynthesis lead to severe multisystem diseases, known as congenital disorders glycosylation (CDG). The clinical appearance CDG is variable, and different types can be distinguished according gene that altered. In this report, we describe molecular basis a novel type disease three unrelated patients diagnosed with CDG-I. Serum transferrin was hypoglycosylated patients' fibroblasts accumulated incomplete lipid-linked oligosaccharide precursors for...
In vitro myogenesis involves a dramatic reorganization of the microtubular network, characterized principally by relocalization microtubule nucleating sites at surface nuclei in myotubes, marked contrast with classical pericentriolar localization observed myoblasts (Tassin, A. M., B. Maro, and M. Bornens, 1985, J. Cell Biol., 100:35-46). Since spatial relationship between Golgi apparatus centrosome is most animal cells, we have decided to follow fate during an immunocytochemical approach,...
Deficiency of the Golgi enzyme UDP-Gal:N-acetylglucosamine β-1,4-galactosyltransferase I (β4GalT I) (E.C.2.4.1.38) causes a new congenital disorder glycosylation (CDG), designated type IId (CDG-IId), severe neurologic disease characterized by hydrocephalus, myopathy, and blood-clotting defects. Analysis oligosaccharides from serum transferrin HPLC, mass spectrometry, lectin binding revealed loss sialic acid galactose residues. In skin fibroblasts leukocytes, galactosyltransferase activity...
Biosynthesis, intracellular transport, and turnover of UDP-galactose:@-D-N-acetylglucosaminide /.3,1-4-transferase was studied in HeLa cells.The enzyme (probably an integral membrane protein) is located the trans cisternae Golgi complex where it involved oligosaccharide chain elongation glycoproteins (Roth, J., Berger, E. G. (1982) J. Cell Biol.93,[223][224][225][226][227][228][229].,Dulse-labeling cells with [36S]methionine combined immunoprecipitation/sodium dodecyl sulfate-polyacrylamide...
Carbohydrate-deficient glycoprotein syndrome (CDGS) represents a class of genetic diseases characterized by abnormal N-linked glycosylation. CDGS patients show large number abnormalities resulting in dysmorphy, encephalopathy, and other organ disorders. The majority CDGSs described to date are related an impaired biosynthesis dolichyl pyrophosphate-linked Glc 3 Man 9 GlcNAc 2 the endoplasmic reticulum. Recently, we identified four novel type accumulation . Elaborating on analogy this finding...
Galactosyltransferase immunoreactive sites were localized in human duodenal enterocytes by the protein A-gold technique on thin sections from low temperature Lowicryl K4M embedded biopsy specimens. Antigenic detected with affinity-purified, monospecific antibodies found at plasma membrane of absorptive most intense labeling appearing along brush border membrane. The lateral exhibited a lower degree level junctional complexes but interdigitations intensely labeled. intensity decreased...
UDP‐galactose: N ‐acetylglucosamine galactosyltransferase was isolated from pooled human milk, amniotic fluid and two different individual samples of malignant ascites. The purification procedure involving successive affinity chromatography steps on ‐acetylglucosamine–agarose α‐lactalbumin–agarose yielded an enzyme preparation homogeneous by size. Under non‐denaturing conditions the ascites enzymes had identical electrophoretic mobility, but they moved faster than milk enzyme. Isoelectric...
Anti-human galactosyltransferase (E.C. 2.4.1.22) antibodies were elicited in rabbits and purified on a galactosyltransferase-agarose column. Purified used to localize acetone-fixed HeLa cells human lung fibroblasts. Both protein A-peroxidase developed with 3-amino 9-ethylcarbazole swine anti-rabbit IgG-fluorescein isothiocyanate served detect binding of anti-galactosyltransferase antibodies. In confluent cultures, staining appeared as concise triangular structure the juxtanuclear region one...