A Transfected Sialyltransferase That Is Elevated in Breast Cancer and Localizes to the medial/trans-Golgi Apparatus Inhibits the Development of core-2–based O-Glycans

Whitehouse, Caroline; Burchell, Joy; Gschmeissner, Stephen; Brockhausen, Inka; Lloyd, Kenneth O.; Taylor-Papadimitriou, Joyce

The relative distribution of the two enzymes was then determined by counting each size of gold particle across the Golgi stacks, using a method developed by T. Nilsson and C. Rabouille (personal communication) . The distance between the beginning of the cis cisternae and the end of the trans compartment was divided into 10 equal fractions and converted to real distances (nm) using the magnification factor of the micrograph. The number of gold particles of each size, in each of the 10 fractions, was counted, converted to a percentage frequency, and plotted against distance as shown in Fig. 10 . This method provides a more detailed outline of the distribution of the GalT and ␣2,3 was higher in their transfectants, further detailed analysis of the Golgi apparatus localization was performed with one of the MTSV1-7 3ST clones (3.14). Golgi localization, was confirmed unambiguously by counting gold particles over 18 Golgi apparatus and an equivalent area of nucleus, as this demonstrated a labeling ratio of 90:1 Golgi stack to nucleus.