Enzymatic Activity of Glycosyltransferase Glt8d1 Promotes Human Glioblastoma Cells Migration

Glioblastoma (GBM) is the most aggressive primary brain tumor characterized by infiltrative migration of malignant glioma cells into the surrounding brain parenchyma. In this study, our analysis of GBM patient cohorts displayed significant higher expression of Glycosyltransferase 8 domain containing 1 ( GLT8D1 ) compared to normal brain tissue and could be associated with impaired patient survival. In vitro an increased GLT8D1 expression significantly enhanced migration of two different sphere-forming GBM cell lines. By in silico analysis we predicted the 3D-structure as well as the active site residues of GLT8D1. The introduction of point mutations in predicted active site reduced its glycosyltransferase activity in vitro and consequently impaired GBM tumor cell migration. Examination of GLT8D1 interaction partners by LC-MS/MS implied proteins associated with cytoskeleton and intracellular transport as potential substrates. In conclusion, we demonstrated that the enzymatic activity of glycosyltransferase GLT8D1 promotes GBM cell migration.