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TUSC3

Function

Acts as accessory component 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. Involved in N-glycosylation of STT3B-dependent substrates. Specifically required for the glycosylation of a subset of acceptor sites that are near cysteine residues; in this function seems to act redundantly with MAGT1. In its oxidized form proposed to form transient mixed disulfides with a glycoprotein substrate to facilitate access of STT3B to the unmodified acceptor site. Has also oxidoreductase-independent functions in the STT3B-containing OST complex possibly involving substrate recognition.

Magnesium transporter.

Involvement in disease

Mental retardation, autosomal recessive 7

MRT7

A disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period.

None

The disease is caused by variants affecting the gene represented in this entry.

Pathway

Protein modification; protein glycosylation.

Sequence similarities

Belongs to the OST3/OST6 family.

Tissue specificity

Expressed in most non-lymphoid cells and tissues examined, including prostate, lung, liver, colon, heart, kidney and pancreas.

Cellular localization

  • Endoplasmic reticulum membrane
  • Multi-pass membrane protein

Alternative names

  • Tumor suppressor candidate 3
  • Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit TUSC3
  • Magnesium uptake/transporter TUSC3
  • Protein N33
  • Oligosaccharyl transferase subunit TUSC3
  • N33
  • TUSC3

Target type

Proteins

Molecular weight

39676Da