Colette Michalak

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Prior work has shown that endocytosis of bovine beta-glucuronidase by human fibroblasts can be mediated by the existence of a Man6P-independent receptor for the recapture and targeting to lysosomes. In this study, we have isolated a peptide (IIIb2) from pronase digested bovine beta-glucuronidase that behaved as competitive inhibitor of the endocytosis of(More)
A new binding protein, which recognizes a specific peptide sequence from pronase digested bovine beta-glucuronidase, has been isolated from bovine liver membranes. Prior work has shown that this peptide (IIIb2) contains a Ser-X-Ser sequence, where X might be a posttranslational modified Trp. This receptor was detergent-extracted from total bovine liver(More)
Extracellular and intraneuronal formation of amyloid-beta aggregates have been demonstrated to be involved in the pathogenesis of Alzheimer's disease. However, the precise mechanism of amyloid-beta neurotoxicity is not completely understood. Previous studies suggest that binding of amyloid-beta to a number of targets have deleterious effects on cellular(More)
The distribution of the cation-independent mannose 6-phosphate and 78 kDa receptors was studied in postnuclear subcellular fractions from two rat liver cell lines. ELISA assays revealed that the mannose 6-phosphate receptor is enriched in the light buoyant Percoll fractions that contain Golgi structures and early endosomes. Most of the 78 kDa receptor is(More)
Intracellular pathogens, such as Mycobacterium tuberculosis, reside in the phagosomes of macrophages where antigenic processing is initiated. Mycobacterial antigen-MHC class II complexes are formed within the phagosome and are then trafficked to the cell surface. Interferon-γ (IFN-γ) and interleukin-10 (IL-10) influence the outcome of M. tuberculosis(More)
In human cells, biotin is essential to maintain metabolic homeostasis and as regulator of gene expression. The enzyme holocarboxylase synthetase (HCS) transforms biotin into its active form 5'-biotinyl-AMP and this compound is used to biotinylate five biotin-dependent carboxylases or to activate a soluble guanylate cyclase (sGC) and a cGMP-dependent protein(More)
Specific antigenic determinants on the membrane surface of Entamoeba histolytica that distinguish it from other Entamoeba species were demonstrated. Evidence for these antigenic determinants was obtained with a monoclonal antibody to E. histolytica which showed not only specificity but also sensitivity as demonstrated in enzyme linked immunosorbent assay.(More)
Endocytosis and transport of bovine liver β-glucuronidase to lysosomes in human fibroblasts are mediated by two receptors: the well-characterized cation-independent mannose 6-phosphate receptor (IGF-II/Man6PR) and an IGF-II/Man6PR-independent receptor, which recognizes a Ser-Trp*-Ser sequence present on the ligand. The latter receptor was detergent(More)
Recent work has shown that the cation-independent mannose 6-phosphate and the 78 kDa receptors for lysosomal enzyme targeting are located in different cell compartments. While the mannose 6-phosphate receptor is enriched in the Percoll fractions that contain Golgi apparatus, most of the 78 kDa receptor is localized in a heavy fraction at the bottom of the(More)