The Conserved Oligomeric Golgi (COG) complex as a regulator of the Golgi-glycosylation machinery

Our basic interest in membrane trafficking pathways implicated in human diseases has prompted us to investigate the function of the Conserved Oligomeric Golgi (COG) complex in membrane transport. The COG is a heterooctameric complex that has been implicated in regulating the transport, retention and/or retrieval of components of the Golgi-glycosylation machinery. Yet, the underlying mechanism of its action remains to be established. Recently, mutations in the genes encoding different subunits of the COG complex have been identified in several CDG patients. CDGs constitute a genetically heterogeneous group of diseases caused by deficient or increased glycosylation of glycoconjugates, such as glycoproteins and glycolipids. The phenotypic spectrum of these disorders ranges from severe to mild disease and from multi-system to mono-organ disease. The severe cases appear in the neonatal period, with a 20% lethality in the first year of life.

Current ongoing studies are aimed at elucidating the mechanisms of COG action in mammalian cells and their involvement in CDGs.

	The COG complex acts as a tethering factor and affects the Golgi structure and the Golgi-glycosylation machinery. Mutations in COG subunits have been identified in CDG patients.