Cell Biology Special Seminar-Dr. Akihiro Harada "Dynamic movement of the Golgi unit and its glycosylation enzyme zones"

Research summary: Knowledge on the distribution and dynamics of glycosylation enzymes in the Golgi is essential for uncovering the mechanism of glycosylation. Here, using combination of CRISPR/Cas9 knockin technology and super-resolution microscopy, we show that the Golgi complex is assembled by a number of small ‘Golgi units’ that have 1-3 micron in diameter. Each Golgi unit contains small domains of glycosylation enzymes which we call ‘zones’. The zones of N- and O-glycosylation enzymes are colocalised. However, they are less colocalised with the zones of a glycosaminoglycan synthesizing enzyme. Golgi units change shapes dynamically and the zones of glycosylation enzymes rapidly move near the rim of the unit. Photobleaching analysis indicates a glycosaminoglycan synthesizing enzyme moves between units. Depletion of giantin dissociates units and prevents the movement of glycosaminoglycan -synthesizing enzymes, which leads to insufficient glycosaminoglycan synthesis. Here, we show the structure-function relationship of the Golgi and implicate its role in human pathogenesis.