Reaction: UDP-N-acetylglucosamine + [Skp1-protein]-hydroxyproline = UDP + [Skp1-protein]-O-(N-acetyl-D-glucosaminyl)hydroxyproline
Other name(s): Skp1-HyPro GlcNAc-transferase; UDP-N-acetylglucosamine (GlcNAc):hydroxyproline polypeptide GlcNAc-transferase; UDP-GlcNAc:Skp1-hydroxyproline GlcNAc-transferase; UDP-GlcNAc:hydroxyproline polypeptide GlcNAc-transferase
Systematic name: UDP-N-acetyl-D-glucosamine:[Skp1-protein]-hydroxyproline N-acetyl-D-glucosaminyl-transferase
Comments: Requires dithiothreitol and a divalent cation for activity. This enzyme commences the building up of a pentasaccharide (Galα1-6Galα1-L-Fucα1-2Galβ1-3GlcNAc) on Hyp-143 of the Dictyostelium protein Skp1, which is required for the ubiquitination of cell-cycle regulatory proteins and transcription factors. The fucose residue is probably in the α configuration [3]. The specificity of the enzyme for Skp1-Hyp-143 and its high affinity for this substrate suggests that it is the GlcNAc-transferase that modifies Skp1 in vivo.
Links to other databases: BRENDA, EXPASY, KEGG, CAS registry number: 256531-81-4
References:
1. van der Wel, H.,Morris, H.R., Panico, M., Paxton, T., Dell, A., Kaplan, L. and West, C.M. Molecular cloning and expression of a UDP-N-acetylglucosamine (GlcNAc):hydroxyproline polypeptide GlcNAc-transferase that modifies Skp1 in the cytoplasm of Dictyostelium. J. Biol. Chem. 277 (2002) 46328-46337. [PMID: 12244115]
2. Teng-umnuay, P., van der Wel, H. and West, C.M. Identification of a UDP-GlcNAc:Skp1-hydroxyproline GlcNAc-transferase in the cytoplasm of Dictyostelium. J. Biol. Chem. 274 (1999) 36392-36402. [PMID: 10593934]
3. West, C.M., van der Wel, H. and Gaucher, E.A. Complex glycosylation of Skp1 in Dictyostelium: implications for the modification of other eukaryotic cytoplasmic and nuclear proteins. Glycobiology 12 (2002) 17R-27R. [PMID: 11886837]