Fig. 6.

Identified glycotransferases involved in O-glycosylation and associated biosynthetic pathway. A, identified glycotransferases were quantified in all four colon segments based on the z-score transformed summed protein intensities for ascending (a), transverse (t), descending (d), and sigmoid (s) colon (n = 4). The O-glycans of the MUC2 mucin as determined previously have shown that human colon has only core 3– and core 4–based O-glycan structures. The biosynthetic pathways of the glycans observed were confirmed by the core glycotransferases identified. The lower highlighted area shows the extension of core 4 glycans, which can terminate in various structures. The highlighted region in the top left shows the identified sulfotransferases acting on both core 3 and core 4 structures. Proteins highlighted by an asterisk (*) were significantly (p < 0.05) regulated between ascending and sigmoid colon.