CHAPTER 8 Part 2

Cytoplasmic Membrane Systems:

Structure, Function, and

Membrane Trafficking

Copyright © 2008 by John Wiley & Sons, Inc.

ER to the Golgi Complex: The first step in vesicular transport ERGIC Region

Visualizing membrane traffic with a fluorescent tag

Vesicular Transport from the ER to the Golgi

The Golgi Complex

Glycosylation in the Golgi Complex

No need to memorize the steps; only the concept is important

Dynamics of Transport through the Golgi Complex

COP1 and COPII Coated Vesicles

Vesicular Transport between membranousCompartments of the biosynthetic/secretorypathway

Roles of COPII proteins in assembling protein coat and capturing cargo

Accumulation of COPI- coated Vesicles

Retrieval of Resident ER Proteins !

Protein Transport from one Golgi cisternae to another can be assayed in a cell-free system (example: cultured fibroblasts); Fig a & b

Fig. a

VSV G protein in vitro contains the additional N-acetylglucosamine!!!This modification is carried out by transferase enzyme that is moved by

retrograde transport vesicles from the wild-type medial-Golgi cisternae to the mutant cis-Golgi cisternae in the reaction mixture (Science 276:1212, 1997).

Fig. b

VERY IMPORTANT DIAGRAM !Read Legend in Text-book; Fig 8.29

Targeting Lysosomal Enzymes To Lysosomes

Formation and Fusion of a Transport Vesicle

Formation of Calthrin coated Vesicles at the TGN

Model for Targeting of Transport Vesicles to Target Membranes

Model for interaction between v- and t-SNAREs leading to membrane fusion and exocytosis

LYSOSOMES

Lysosomes

Liver Cells Neuron of a Human withLysosomal Storage DisorderAccumulation of unidgested glycolipids