COG5 Gene

The COG5 gene provides instructions for making a protein called component of oligomeric Golgi complex 5 (COG5). As its name suggests, COG5 is one piece of a group of proteins known as the conserved oligomeric Golgi (COG) complex. This complex functions in the Golgi apparatus, which is a cell structure in which newly produced proteins are modified. One process that occurs in the Golgi apparatus is glycosylation, by which sugar molecules (oligosaccharides) are attached to proteins and fats. Glycosylation modifies proteins so they can perform a wider variety of functions.

The COG complex takes part in the transport of proteins, including the enzymes that perform glycosylation, within the Golgi apparatus. COG is specifically involved in retrograde transport, which moves proteins backward through the Golgi apparatus. Retrograde transport is important for recycling Golgi proteins and ensuring that they are in the correct location in the structure, which is key to proper glycosylation. The proteins are transported in sac-like structures called vesicles that attach to the Golgi membrane and release the contents into the Golgi apparatus. The COG complex controls the attachment (tethering) of the vesicles to the Golgi membrane.