STT3B_HUMAN

Source: PM19886704
PM23856902
Marked as 'Integral membrane protein'
Confidence: low (only semi-automatic identification from reviews) Search PubMed for
(RBC AND this entry)
Gene names: STT3B , SIMP
Protein names and data: STT3B_HUMAN , Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit STT3B; Oligosaccharyl transferase subunit STT3B; STT3-B; 2.4.99.18 , Source of immunodominant MHC-associated peptides homolog Lenght: 826 a.a.
Mass: 93674 Da
fasta formatted sequence
Function: Catalytic subunit of the N-oligosaccharyl transferase (OST) complex which catalyzes the transfer of a high mannose oligosaccharide from a lipid-linked oligosaccharide donor to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). STT3B is present in a small subset of OST complexes and mediates both cotranslational and post-translational N-glycosylation of target proteins: STT3B-containing complexes are required for efficient cotranslational glycosylation and while they are less competent than STT3A-containing complexes for cotranslational glycosylation, they have the ability to mediate glycosylation of some nascent sites that are not accessible for STT3A. STT3B-containing complexes also act post-translationally and mediate modification of skipped glycosylation sites in unfolded proteins. Plays a role in ER-associated degradation (ERAD) pathway that mediates ubiquitin-dependent degradation of misfolded endoplasmic reticulum proteins by mediating N-glycosylation of unfolded proteins, which are then recognized by the ERAD pathway and targeted for degradation. Mediates glycosylation of the disease variant AMYL- TTR 'Asp-38' of TTR at 'Asn-118', leading to its degradation.
Catalytic activity: Dolichyl diphosphooligosaccharide + [protein]- L-asparagine = dolichyl diphosphate + a glycoprotein with the oligosaccharide chain attached by N-beta-D-glycosyl linkage to a protein L-asparagine.
Pathway: Protein modification; protein glycosylation.
Cellular location: Endoplasmic reticulum membrane; Multi-pass membrane protein.
Tissue specificity: Expressed in heart, brain, placenta, lung, liver, muscle, kidney and pancreas. Expressed in skin fibroblasts (at protein level).

Database cross-references

UniProt: Q8TCJ2
Ensembl: ENST00000295770
MIM: 608605
neXtProt: NX_Q8TCJ2
Antibodypedia: Q8TCJ2 (may not find the protein thus also not any antibody)
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