CD1-MR1 2015* Biosynthesis of a-linked glycosylceramides in mammals (#34)
Glucose and galactose are the two proximal sugars of the vast majority of mammalian glycolipids. Both sugars are linked to ceramides as b anomers by UCGC and UGT8, two inverting transferases that use aUDP-glucose and aUDP-galactose as glycan donors, respectively. The recent discovery that a-linked glucosyl and galactosylceramides were synthesized by mammalian cells and relevant to the biology of invariant NKT cells, has made us embark for the search of the biosynthetic routes of a glycosylceramides. A systematic CRISPR/Cas9 knockout of all enzymes and molecules critical for the synthesis of ceramides and UDP-glucose and galactose synthesis and transport has been initiated. Antibodies specific for a galactosylceramide and a glucosylceramides have been produced to facilitate the screening and complement functional and biochemical readouts. Early results have confirmed a large number of already known phenotypes, and more importantly have identified key enzymes for each of the pathways. An enzyme essential for the synthesis of a galactosylceramide has been confirmed in vivo by gene knockout. Updates will be presented.
