Cloned (Comment) | Organism |
---|---|
recombinant nuclear expression of the enzyme sequences fused to a tag sequence encoding for a V5-epitope in Chlamydomonas reinhardtii | Phaeodactylum tricornutum |
recombinant nuclear expression of the enzyme sequences fused to a tag sequence encoding for a V5-epitope in Chlamydomonas reinhardtii | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | eukaryotic N-glycosylation pathways are dependent of N-acetylglucosaminyltransferase I (GnTI), a key glycosyltransferase opening the door to the formation of complex-type N-glycans by transferring a N-acetylglucosamine residue onto the Man5GlcNAc2 intermediate. In contrast, glycans N-linked to Chlamydomonas reinhardtii proteins arise from a GnTI-independent Golgi processing of oligomannosides giving rise to Man5GlcNAc2 substituted eventually with one or two xylose(s). Chlamydomonas reinhardtii proteins carry linear Man5GlcNAc2 instead of the branched structure usually found in eukaryotes. Moreover, characterization of the lipid-linked oligosaccharide precursor demonstrated that Chlamydomonas reinhardtii exhibit a Glc3Man5GlcNAc2 dolichol diphosphate precursor. This precursor is then trimmed into a linear Man5GlcNAc2 that is not substrate for GnTI. Expression of GnTI cDNAs originated from Arabidopsis and the diatom Phaeodactylum tricornutum cause no modification of the N-glycans in the GnTI transformed cells. Cells expressing GnTI exhibit an altered phenotype with large vacuoles, increase of ROS production and accumulation of starch granules, suggesting the activation of stress responses likely due to the perturbation of the Golgi apparatus | Phaeodactylum tricornutum |
additional information | eukaryotic N-glycosylation pathways are dependent of N-acetylglucosaminyltransferase I (GnTI), a key glycosyltransferase opening the door to the formation of complex-type N-glycans by transferring a N-acetylglucosamine residue onto the Man5GlcNAc2 intermediate. In contrast, glycans N-linked to Chlamydomonas reinhardtii proteins arise from a GnTI-independent Golgi processing of oligomannosides giving rise to Man5GlcNAc2 substituted eventually with one or two xylose(s). Chlamydomonas reinhardtii proteins carry linear Man5GlcNAc2 instead of the branched structure usually found in eukaryotes. Moreover, characterization of the lipid-linked oligosaccharide precursor demonstrated that Chlamydomonas reinhardtii exhibit a Glc3Man5GlcNAc2 dolichol diphosphate precursor. This precursor is then trimmed into a linear Man5GlcNAc2 that is not substrate for GnTI. Expression of GnTI cDNAs originated from Arabidopsis and the diatom Phaeodactylum tricornutum cause no modification of the N-glycans in the GnTI transformed cells. Cells expressing GnTI exhibit an altered phenotype with large vacuoles, increase of ROS production and accumulation of starch granules, suggesting the activation of stress responses likely due to the perturbation of the Golgi apparatus | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
Golgi membrane | - |
Arabidopsis thaliana | 139 | - |
membrane | - |
Phaeodactylum tricornutum | 16020 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mn2+ | required | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine + Man5GlcNAc2-[protein] | Phaeodactylum tricornutum | - |
UDP + Man5GlcNAc3-[protein] | - |
? | |
UDP-N-acetyl-alpha-D-glucosamine + Man5GlcNAc2-[protein] | Arabidopsis thaliana | - |
UDP + Man5GlcNAc3-[protein] | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q9XGM8 | - |
- |
Phaeodactylum tricornutum | G0WVT5 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
UDP-N-acetyl-alpha-D-glucosamine + Man5GlcNAc2-[protein] | - |
Phaeodactylum tricornutum | UDP + Man5GlcNAc3-[protein] | - |
? | |
UDP-N-acetyl-alpha-D-glucosamine + Man5GlcNAc2-[protein] | - |
Arabidopsis thaliana | UDP + Man5GlcNAc3-[protein] | - |
? |
Synonyms | Comment | Organism |
---|---|---|
AtGnTI | - |
Arabidopsis thaliana |
GnTI | - |
Phaeodactylum tricornutum |
GnTI | - |
Arabidopsis thaliana |
N-acetylglucosaminyltransferase I | - |
Phaeodactylum tricornutum |
N-acetylglucosaminyltransferase I | - |
Arabidopsis thaliana |
PtGnTI | - |
Phaeodactylum tricornutum |
General Information | Comment | Organism |
---|---|---|
malfunction | enzyme-deficient Chlamydomonas reinhardtii cells expressing eukaryotic GnTI from Arabidopsis thaliana exhibit an altered phenotype with large vacuoles, increase of ROS production and accumulation of starch granules, suggesting the activation of stress responses likely due to the perturbation of the Golgi apparatus | Arabidopsis thaliana |
malfunction | enzyme-deficient Chlamydomonas reinhardtii cells expressing eukaryotic GnTI from Phaeodactylum tricornutum exhibit an altered phenotype with large vacuoles, increase of ROS production and accumulation of starch granules, suggesting the activation of stress responses likely due to the perturbation of the Golgi apparatus | Phaeodactylum tricornutum |
metabolism | eukaryotic N-glycosylation pathways are dependent of N-acetylglucosaminyltransferase I (GnTI), a key glycosyltransferase opening the door to the formation of complex-type N-glycans by transferring a N-acetylglucosamine residue onto the Man5GlcNAc2 intermediate | Phaeodactylum tricornutum |
metabolism | eukaryotic N-glycosylation pathways are dependent of N-acetylglucosaminyltransferase I (GnTI), a key glycosyltransferase opening the door to the formation of complex-type N-glycans by transferring a N-acetylglucosamine residue onto the Man5GlcNAc2 intermediate | Arabidopsis thaliana |
physiological function | AtGnTI (At4g38240) encodes for a Golgi enzyme that is responsible for the transfer of a terminal GlcNAc residue onto Man5GlcNAc2 N-glycan | Arabidopsis thaliana |
physiological function | PtGnTI restores in vivo the biosynthesis of complex-type N-glycans in CHO Lec1 mutant that lacks endogenous GnTI activity | Phaeodactylum tricornutum |