The N-acetylglucosaminyltransferase of the embryonic chick retina which catalyze the process dolichol phosphate + UDP-GlcNAc Mg2+ leads to GlcNAc-P-P-dolichol + (GlcNAc)2-P-P-dolichol were stimulated 7- to 15-fold by dolichol phosphate-mannose added exogenously to the incubation medium or generated in situ. The relative molar distribution as measured by gel filtration on Bio-Gel P-4 (-400) of t...

The uncharacterized gene previously proposed as a mannose-6-phosphate isomerase from Bacillus subtilis was cloned and expressed in Escherichia coli. The maximal activity of the recombinant enzyme was observed at pH 7.5 and 40 degrees C in the presence of 0.5 mM Co(2+). The isomerization activity was specific for aldose substrates possessing hydroxyl groups oriented in the same direction at the ...

Coxiella burnetii, the etiologic agent of human Q fever, is a gram-negative and naturally obligate intracellular bacterium. The O-specific polysaccharide chain (O-PS) of the lipopolysaccharide (LPS) of C. burnetii is considered a heteropolymer of the two unusual sugars β-D-virenose and dihydrohydroxystreptose and mannose. We hypothesize that GDP-D-mannose is a metabolic intermediate to GDP-β-D-...

TIP47 (tail-interacting protein of 47 kDa) binds to the cytoplasmic domains of the cation-independent and cation-dependent mannose 6-phosphate receptors and is required for their transport from late endosomes to the trans Golgi network in vitro and in vivo. We report here a quantitative analysis of the interaction of recombinant TIP47 with mannose 6-phosphate receptor cytoplasmic domains. Recom...

Normal and malignant lymphocytes can migrate from the bloodstream into lymph nodes and Peyer's patches. This process helps distribute normal lymphocytes throughout the lymphoid system and may provide a portal of entry for circulating malignant cells. An adhesive interaction between lymphocytes and the endothelium of postcapillary venules is the first step in the migratory process. We have recen...

Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phospho...

Congenital disorder of glycosylation (PMM2-CDG) results from mutations in pmm2, which encodes the phosphomannomutase (Pmm) that converts mannose-6-phosphate (M6P) to mannose-1-phosphate (M1P). Patients have wide-spectrum clinical abnormalities associated with impaired protein N-glycosylation. Although it has been widely proposed that Pmm2 deficiency depletes M1P, a precursor of GDP-mannose, and...

Populations of Chinese hamster ovary cells selected for resistance to diphtheria toxin were found to be highly enriched for mutants deficient in the uptake of lysosomal hydrolases via the mannose 6-phosphate receptor. One doubly defective mutant, DTF 1-5-1, exhibited increased resistance to Sindbis virus, although it was able to bind and internalize virus normally. Normal production of virus wa...

A positive selectable marker system was adapted for transformation of mature embryo-derived calli of Indica rice (Oryza sativa L.) utilizing the PMI gene encoding for phosphomannose-isomerase that converts mannose-6-phosphate to fructose-6-phosphate. The transformed cells grew on medium supplemented with 3% mannose as carbon source and calli were selected on media containing various concentrati...

Softening of the flesh and the rise in ethylene evolution and respiration associated with ripening in pear (Pyrus communis L.) fruit was delayed when mannose was vacuum infiltrated into intact fruit. The extent of delay could be modified by altering the concentration or the volume of mannose applied to the fruit. Inhibition of ripening was associated with phosphorylation of mannose to mannose 6...