摘要：SummaryGlycoprotein processing along a complex highly compartmentalized pathway is a hallmark of eukaryotic cells. We followed the kinetics of intracellular, site-specific glycan processing of a model protein with five distinct N-glycosylation sites and deduced a mathematical model of the secretory pathway that describes a complex set of processing reactions localized in defined intracellular compartments such as the endoplasmic reticulum the Golgi, or the lysosome. The model was able to accommodate site-specific N-glycan processing and we identified phosphorylated glycan structures of the mannose-6-phosphate pathway responsible for the lysosomal sorting of the glycoprotein. Importantly, our model protein can take different routes of the cellular secretory pathway, resulting in an increased glycan complexity of the secreted protein.Graphical abstractDisplay OmittedHighlights•The intracellular processing of an N-glycoprotein was analyzed in CHO cells•Kinetic data were obtained by MS/MS analysis in combination with SILAC•Mathematical model of the processing and the secretory pathway was deduced•Testing of the model revealed the predicted phosphorylated glycan speciesCell biology; Integrative aspects of cell biology; Mathematical biosciences.
