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 membranous
Compartments of the biosynthetic/secretory
pathway
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 with
Lysosomal Storage Disorder
Accumulation of unidgested glycolipids