Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Gene Ontology annotation based on curation of immunofluorescence data
Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara
Combined Automated Annotation using Multiple IEA Methods
Expression cloning of a cDNA encoding UDP-GlcNAc:Gal beta 1-3-GalNAc-R (GlcNAc to GalNAc) beta 1-6GlcNAc transferase by gene transfer into CHO cells expressing polyoma large tumor antigen.
-
Expression cloning followed by expression of the catalytic domain as a protein A fusion demonstrated that the cDNA encodes the core 2 beta-1,6-N-acetylglucosaminyltransferase forming Gal-beta1-3(GlcNAc-beta1-6)GalNAc.
"enabled us to demonstrate unequivocally that the cDNA encodes the core 2 beta-1,6-N-acetylglucosaminyltransferase, the enzyme responsible for the formation of Gal beta 1-3(GlcNAc beta 1-6)GalNAc structures"
-
Acceptor specificity was tested against the substrates of related beta-1,6-GlcNAc transferases with no activity detected, which excludes the paralog-specificity error common in large glycosyltransferase families.
"No activity with this enzyme was detected toward the acceptors for other beta 1-6GlcNAc transferases"
Golgi phosphoprotein 3 determines cell binding properties under dynamic flow by controlling Golgi localization of core 2 N-acetylglucosaminyltransferase 1.
-
GOLPH3 binds the C2GnT1 cytoplasmic tail via its LLRRR motif and is required for Golgi retention of the enzyme; confocal microscopy against cis-, medial- and trans-Golgi markers localises C2GnT1 across the Golgi stack.
"demonstrated that C2GnT1 binds to GOLPH3 via the LLRRR(9) sequence in the CT"
-
Direct siRNA knockdown of C2GnT1 reduced PSGL-1-associated core 2 sialyl Lewis x by 74.6% without reducing PSGL-1 protein levels, establishing the enzyme's requirement for building this O-glycan structure.
"following the treatment with C2GnT1 siRNA, there was a 74.6% decrease in PSGL-1-associated C2-O-sLe x"
-
The tethering, rolling and ICAM-1 adhesion assays were performed on GOLPH3-depleted cells rather than on C2GnT1-depleted cells, so the cell-behaviour annotations on GCNT1 rest on a two-step inference through enzyme mislocalisation.
"GOLPH3 knockdown results in reduced synthesis of C2-O-sLe(x) associated with P-selectin glycoprotein ligand-1, reduced cell tethering to and rolling on immobilized P- or E-selectin"
Termination of O-glycan biosynthesis
GCNT1 transfers GlcNAc to Core 1 glycoproteins forming Core 2 glycoproteins
OpenScientist hypothesis report: GCNT1 has nuclear speck (GO:0016607)
-
Independent blinded assessment found the nuclear speck assignment weakly supported and consistent with an antibody artefact, on the basis that GCNT1 is the only Golgi type II glycosyltransferase in a comparator panel reported with nuclear speckles, and that its nuclear call replaces rather than supplements the expected Golgi signal.
"GCNT1's speckle call **replaces** rather than **supplements** the expected Golgi signal"