The Department of Biomedicine

BBB seminar: Sakari Kellokumpu

Glycosyltransferase complexes: a new view to glycosylation and cancer-associated glycosylation abnormalities

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Sakari Kellokumpu
Department of Biochemistry, University of Oulu, Finland

Congenital diseases of glycosylation (CDG), inflammation, diabetes and cancers represent a group of disorders, in which cellular glycoconjugates – glycans – are altered. These altered glycan structures are important, as they often contribute to disease onset/progression. For example, in cancers, they enhance invasion and metastasis – the major cause of death in cancer patients. Glycans are known to be synthesized mainly in the Golgi apparatus by the sequential actions of dozens of functionally distinct glycosyltransferases and glycosidases. Yet, it is still far from clear how the functions of these enzymes are orchestrated (dysregulated) to facilitate (abrogate) faithful synthesis of a large number of distinct and functionally important glycan structures. The main focus of the presentation will be to summarize our recent evidence and introduce a new concept, which entails that under normal conditions (but not in cancer cells) glycosyltransferases exist and also function as homo- and/or heteromeric complexes, and not as monomers as previously thought. The other topic to be covered relates to unexpected membrane dynamics that these complexes show during their recycling between the early secretory compartments.

Chairperson: Jaakko Saraste, Department of Biomedicine