What is "ribophorin"

n. (context biochemistry English) Any of a group of transmembrane glycoproteins located in the membrane of the rough endoplasmic reticulum, but absent in the membrane of the smooth endoplasmic reticulum.

Ribophorins are 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 proteic complex oligosaccharyltransferase (OST) as two different subunits of the named complex. Ribophorin I and II are only present in eukaryote cells.

Both types of ribophorins develop a key role in the binding of ribosomes to the rough endoplasmic reticulum as well as in the co-translational processes that depend on this interaction. The content of ribophorin of the rough endoplasmic reticulum is equal to the stoichiometric number of ribosomal units. Therefore, this suggests the great importance, abundance and good preservation of these proteins in the reticulum. Consequently, defects in the genes that encode these proteins may cause congenital disorders and devastating consequences; ribophorin I and II are encoded by the genes RPN1 and RPN2 respectively.

The ribophorins are soluble in non-ionic detergents such as Triton X-100.