Graduate Cell Biology · Secretory Pathway
The Golgi Apparatus
The cell’s sorting and modification hub — where every secreted protein is glycosylated, every membrane protein is post-translationally finalised, and every destination address is decided.
About This Course
Camillo Golgi, working alone in a Pavia kitchen in 1898, discovered the apparato reticolare interno using silver-nitrate impregnation of neurons. For forty years his “apparatus” was dismissed as an artefact. The electron microscope settled the argument in the 1950s: the Golgi is a real organelle, a stack of four to ten flattened membrane cisternae (dictyosome) through which every secreted and most membrane proteins pass. It is the cell’s sorting centre: cargo enters from the ER at the cis face, is modified (glycosylation, sulphation, proteolytic maturation) across medial and trans cisternae, and is sorted at the trans-Golgi network (TGN) to lysosomes, endosomes, secretory granules, or the plasma membrane.
Seven modules cover architecture, the cisternal-maturation debate, the COPI/COPII vesicle machinery, glycosylation biology, mitotic disassembly, and the diseases (CDG and cancer metastasis) that trace to Golgi dysfunction.
Seven Modules
M0
Discovery & Architecture
Camillo Golgi 1898 silver nitrate, cis/medial/trans stacks, TGN, ribbon organisation in mammals, the cisternae as chemically distinct compartments.
M1
Cisternal Maturation
Cisternal progression vs vesicular-transport models, Glick & Malhotra, retrograde COPI movement of residents, live-imaging proof in yeast (Matsuura-Tokita 2006).
M2
COPI & COPII Vesicles
COPII (Sar1, Sec23/24, Sec13/31) for ER-to-Golgi anterograde; COPI (Arf1, 7-subunit coatomer) for intra-Golgi and Golgi-to-ER retrograde. Sar1 curvature, cargo recognition.
M3
Glycosylation
N-linked (OST at ER, trimming + elaboration in Golgi), O-linked (GalNAc start), mucin-type, complex oligosaccharides, sialyl-Lewis X selectin ligands, blood-group antigens.
M4
Disassembly in Mitosis
Golgi dispersal at prophase, GRASP phosphorylation, haspin + CDK1 triggers, reassembly at telophase, "Golgi checkpoint" (Sutterlin).
M5
Golgi in Disease (CDG)
Congenital disorders of glycosylation (>150 subtypes), COG complex CDG, ALG1-13, SLC35 transporters, metastasis and aberrant sialylation, cancer selectin recognition.
M6
Unconventional Secretion
Type I-IV unconventional secretion, FGF2 direct membrane translocation, IL-1β via gasdermin pores, CUPS compartment in yeast, relevance in inflammation.
Cross-Links
Organelles,Endoplasmic Reticulum,Ribosome,Molecular Biology.