The translocon is a complex of proteins associated with the translocation of polypeptides across membranes. In eukaryotes the term translocon most commonly refers to the complex that transports nascent polypeptides with a targeting signal sequence into the interior space of the endoplasmic reticulum (ER) from the cytosol. This translocation process requires the protein to cross a hydrophobic lipid bilayer. The same complex is also used to integrate nascent proteins into the membrane itself. In prokaryotes, a similar protein complex transports polypeptides across the (inner) plasma membrane or integrates membrane proteins. In either case, the protein complex are formed from Sec proteins, with the heterotrimeric Sec61 being the channel. In prokaryotes, the homologous channel complex is known as SecYEG.
Oligosaccharyltransferase or OST (EC 2.4.1.119) is a membrane protein complex that transfers a 14-sugar oligosaccharide from dolichol to nascent protein. It is a type of glycosyltransferase. The sugar Glc3Man9GlcNAc2 (where Glc=Glucose, Man=Mannose, and GlcNAc=N-acetylglucosamine) is attached to an asparagine (Asn) residue in the sequence Asn-X-Ser or Asn-X-Thr where X is any amino acid except proline. This sequence is called a glycosylation sequon. The reaction catalyzed by OST is the central step in the N-linked glycosylation pathway.
Ribophorins are dome shaped transmembrane glycoproteins which are located in the membrane of the rough endoplasmic reticulum, but are absent in the membrane of the smooth endoplasmic reticulum. There are two types of ribophorines: ribophorin I and II. These act in the protein complex oligosaccharyltransferase (OST) as two different subunits of the named complex. Ribophorin I and II are only present in eukaryote cells.
Activating transcription factor 6, also known as ATF6, is a protein that, in humans, is encoded by the ATF6 gene and is involved in the unfolded protein response.
Glucosidase 2 subunit beta is an enzyme that in humans is encoded by the PRKCSH gene.
Sarcoplasmic/endoplasmic reticulum calcium ATPase 3 is an enzyme that in humans is encoded by the ATP2A3 gene.
Selenoprotein S, also known as SELS, is a human gene.
Dolichyl-diphosphooligosaccharide—protein glycosyltransferase subunit 1 is an enzyme that in humans is encoded by the RPN1 gene.
Protein SEC13 homolog is a protein that in humans is encoded by the SEC13 gene.
Translocon-associated protein subunit alpha is a protein that in humans is encoded by the SSR1 gene.
CAMP responsive element binding protein-like 1, also known as CREBL1, is a protein which in humans is encoded by the CREBL1 gene.
Ribosome-binding protein 1, also referred to as p180, is a protein that in humans is encoded by the RRBP1 gene.
Protein transport protein Sec61 subunit alpha isoform 1 is a protein that in humans is encoded by the SEC61A1 gene.
Translocon-associated protein subunit beta also known as TRAP-beta is a protein that in humans is encoded by the SSR2 gene.
Translocation protein SEC63 homolog is a protein that in humans is encoded by the SEC63 gene.
Protein transport protein Sec61 subunit gamma is a protein that in humans is encoded by the SEC61G gene.
Signal recognition particle receptor subunit beta is a protein that in humans is encoded by the SRPRB gene.
Conserved oligomeric Golgi complex subunit 1 is a protein that in humans is encoded by the COG1 gene.
Translocation protein SEC62 is a protein that in humans is encoded by the SEC62 gene.
dolichyl-phosphate mannosyltransferase polypeptide 3, also known as DPM3, is a human gene.
