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alpha(1,3)Fucosylated oligosaccharides represent components of leukocyte counterreceptors for E- and P-selectins and of L-selectin ligands expressed by lymph node high endothelial venules (HEV). The identity of the alpha(1,3)fucosyltransferase(s) required for their expression has been uncertain, as has a requirement for alpha(1,3)fucosylation in HEV(More)
We have cloned the cDNA encoding human GDP-mannose 4,6-dehydratase, the first enzyme in the pathway converting GDP-mannose to GDP-fucose. The message is expressed in all tissues and cell lines examined, and the cDNA complements Lec13, a Chinese Hamster Ovary cell line deficient in GDP-mannose 4,6-dehydratase activity. The human GDP-mannose 4,6-dehydratase(More)
E-selectin is the inducible adhesion protein on the surface of endothelial cells which has a crucial role in the initial stages of recruitment of leucocytes to sites of inflammation. In addition, it is almost certainly involved in tumor cell adhesion and metastasis. This report is concerned with identification of a new class of oligosaccharide(More)
The availability of Tetrahymena pre-rRNA of discrete size, produced by transcription of recombinant plasmids with bacteriophage SP6 RNA polymerase, has permitted a more detailed investigation of the self-splicing reaction. The predicted splicing intermediate, the product of cleavage by guanosine at the 5' splice site, was identified. This intermediate was(More)
The dinucleotide CpUOH, when incubated with self-splicing Tetrahymena pre-rRNA in the absence of GTP, functions as a 5' exon. It cleaves the precursor exactly at the 3' splice site and becomes covalently ligated to the 3' exon. Other oligonucleotides with sequences that resemble CUCUCU, the sequence at the 3' end of the 5' exon, can add to the 3' exon in(More)
BACKGROUND GDP-mannose 4,6 dehydratase (GMD) catalyzes the conversion of GDP-(D)-mannose to GDP-4-keto, 6-deoxy-(D)-mannose. This is the first and regulatory step in the de novo biosynthesis of GDP-(L)-fucose. Fucose forms part of a number of glycoconjugates, including the ABO blood groups and the selectin ligand sialyl Lewis X. Defects in GDP-fucose(More)
Recently the genes encoding the human and Escherichia coli GDP-mannose dehydratase and GDP-fucose synthetase (GFS) protein have been cloned and it has been shown that these two proteins alone are sufficient to convert GDP mannose to GDP fucose in vitro. GDP-fucose synthetase from E. coli is a novel dual function enzyme in that it catalyzes epimerizations(More)
The nadD gene, encoding the enzyme nicotinic acid mononucleotide (NaMN) adenylyltransferase (AT), is essential for the synthesis of NAD and subsequent viability of the cell. The nadD gene in Bacillus subtilis (yqeJ) was identified by sequence homology with other bacterial nadD genes and by biochemical characterization of the gene product. NaMN AT catalyzes(More)
BACKGROUND . In all species examined, GDP-fucose is synthesized from GDP-mannose in a three-step reaction catalyzed by two enzymes, GDP-mannose 4,6 dehydratase and a dual function 3, 5-epimerase-4-reductase named GDP-fucose synthetase. In this latter aspect fucose biosynthesis differs from that of other deoxy and dideoxy sugars, in which the epimerase and(More)
P-selectin glycoprotein ligand-1 (PSGL-1) is a high-affinity counterreceptor for P-selectin on myeloid cells and activated T-cells. In addition, PSGL-1 can serve, both in vitro and in vivo, as an E-selectin ligand. Appropriate glycosylation of PSGL-1 is crucial for binding to P-selectin. Functional PSGL-1 is known to bear sialyl lewis X (SLex) or a closely(More)