BISC 3754 Lecture Notes - Lecture 13: Phagocytosis, Phosphotransferase, Endoglycosidase
11 Apr 2018
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Entry= cis-golgi (near er) medial trans golgi= exit. Plant cells have golgi dispersed in cytoplasm. Cis-golgi network (cgn)= fused vesicular tubular clusters arriving from er. Send proteins and lipids from er through trans-golgi network & to plasma mem/other destinations. Trans-golgi network (tgn) endosome, secretory vesicles or cell surface. Removal of mannose/addition of n-acetylglucosamine occurs in cis & medial cisternae. Addition of galactose & sialic acid occurs in trans cisternae/tgn. Golgi glycosidases & glycosyl transferases are single pass transmembrane protein complexes. Cgn sorting= phosphorylation of oligosaccharides (only somal proteins) Proteins sorted to lysosomes, secretory vesicles or plasma membrane. Complex oligosaccharides= original n-linked oligosaccharides added in the er is trimmed and more sugars are added. High mannose oligosaccharides= original oligosaccharide is trimmed but no new sugars added. Sialic acid complex oligosaccharides have negative charge. Processed vs high mannose depends on location in protein. Accessible to enzymes in golgi= likely to be processed.
