Mucha, J., Domlatil, J., Lochnit, G., Rendic, D., Paschinger, K., Hinterkprner, G., Hofinger, A., Kosma, P., Wilson, I.B.H. (2004). The Drosophila melanogaster homologue of the human histo-blood group Pk gene encodes a glycolipid-modifying α1,4-N-acetylgalactosaminyltransferase.  Biochem. J. 382(1): 67--74.

FBrf0179897

Research paper

Insects express arthro-series glycosphingolipids, which contain an alpha1,4-linked GalNAc residue. To determine the genetic basis for this linkage, we cloned a cDNA (CG17223) from Drosophila melanogaster encoding a protein with homology to mammalian alpha1,4-glycosyltransferases and expressed it in the yeast Pichia pastoris. Culture supernatants from the transformed yeast were found to display a novel UDP-GalNAc:GalNAcbeta1,4GlcNAcbeta1-R alpha-N-acetylgalactosaminyltransferase activity when using either a glycolipid, p-nitrophenylglycoside or an N-glycan carrying one or two terminal beta-N-acetylgalactosamine residues. NMR and MS in combination with glycosidase digestion and methylation analysis indicate that the cloned cDNA encodes an alpha1,4-N-acetylgalactosaminyltransferase. We hypothesize that this enzyme and its orthologues in other insects are required for the biosynthesis of the N5a and subsequent members of the arthro-series of glycolipids as well as of N-glycan receptors for Bacillus thuringiensis crystal toxin Cry1Ac.

PMC1133916 (PMC) (EuropePMC)