Missing COGs

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Science  07 May 2004:
Vol. 304, Issue 5672, pp. 797
DOI: 10.1126/science.304.5672.797b

Protein glycosylation is important for the function of many secretory and membrane proteins. In humans, congenital disorders of glycosylation (CDG) can result in problems in many physiological systems, leading to mental retardation, liver malfunctions, and organ failure. Wu et al. describe the cellular consequences of CDG in two siblings who were identified as having the same point mutation in a gene encoding the COG-7 subunit of the conserved oligomeric Golgi (COG) complex. The COG complex is involved in maintaining Golgi membrane traffic and thereby in promoting proper glycosylation. Fibroblasts from the patients were deficient in COG-7 and exhibited an aberrant distribution of COG complex components, and also showed altered membrane traffic through the Golgi and disrupted glycosylation patterns. The normal cellular phenotype could be restored by engineering the expression of COG-7. Thus, fatal forms of CDG may be the result of a Golgi trafficking defect, rather than the outcome of defects in specific glycosylation enzymes. — SMH

Nature Med. 10.1038/nm1041 (2004).

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