Does glycosylation play a role in adaptation to altered oxygenation?. (360G-Wellcome-090112_Z_09_Z)

Altering oxygen tension results in major adaptive changes in cell phenotype, metabolism and intercellular signalling. Hypoxia inducible factor (HIF) plays a central role in regulating the expression of many genes leading to these adaptive responses. Cells with constitutive HIF activation are a powerful system for investigating how HIF is regulated; previously leading to the recognition of the central role of VHL in HIF ubiquitylation. I will investigate a Chinese hamster ovary (CHO) cell li ne M6.19, which has constitutively activated HIF and harbours a glycosylation defect, analogous to that of the glycosylation mutant, Lec8. Furthermore these mutants display enhanced clonogenic survival in hypoxic conditions. My hypothesis is that glycosylation plays a role in adaptation to altered oxygenation. I aim to: i) Determine the underlying genetic defect in glycosylation in M6.19. ii) Determine which glycosylation gene(s) enhance clonogenic growth in hypoxia, and the role of HIF in this growth adaptation. iii) Investigate whether humans with evidence of an aberrant hypoxic response have mutations in the gene(s) identified in ii). This study will determine whether defective glycosylation leads to an adaptation in growth responses in hypoxia and HIF activation, and may provide new insights for the treatment of cancer, ischemia and renal disease.