Glycosylation regulates turnover of cyclooxygenase-2. FEBS Lett. 580, 6533–6536 Received for publication May 9, 2008. Accepted for publication July 24

Abstract Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step in the prostanoid biosynthesis pathway, converting arachidonic acid into prostaglandin H 2 . COX-2 exists as 72 and 74 kDa glycoforms, the latter resulting from an additional oligosaccharide chain at residue Asn 580 . In this study, Asn 580 was mutated to determine the biological significance of this variable glycosylation. COS-1 cells transfected with the mutant gene were unable to express the 74 kDa glycoform and were found to accumulate more COX-2 protein and have five times greater COX-2 activity than cells expressing both glycoforms. Thus, COX-2 turnover appears to depend upon glycosylation of the 72 kDa glycoform. Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies