Endomembranes &

Protein Trafficking

Chapter 8

Part 1

Major Intracellular Compartments of the Cell

Eucaryotic cell Compartments

Simplified Road Map of Protein Traffick

Protein Trafficking

Approaches to the Study of Endomembranes

Autoradiography: Site & Synthesis of Secretory Proteins

The Secretory Pathway:Pancreatic Acinar Cell: Autoradiography showing

movement of labeled secretory proteins (red color = black silver grains)

Use of GFP reveals movement of proteins within a living cell

Use of GFP reveals movement of proteins within a living cell

Biochemical Analysis of Subcellular Fractions

Cell-Free SystemsFormation of Coated Vesicles using liposomes incubated with

protein components identified to be required for vesicle budding in a cell

Use of Genetic Mutants in the Study of Secretion: The Yeast Model

The Endoplasmic Reticulum (ER)

Polarized Structure of a Secretory CellMucus-secreting cells from Rat Colon

Overview of Protein Sorting

Isolation of Rough ER (Microsomes)

The Signal Hypothesis ExperimentIncorporation of Secretory Proteins into Microsomes

The Signal Hypothesis ExperimentIncorporation of Secretory Proteins into Microsomes

The Signal Hypothesis Experiment Incorporation of Secretory Proteins into Microsomes SDS-Gel Electrophoresis Analysis

Translation on free ribosomes Translation on Microsomes

Secretory ProteinSecretory Protein

The Signal Hypothesis Continued

The Signal Hypothesis Continued

The Signal Sequence of Growth Hormone

Signal Peptidase Processing Enzyme located in ER

Schematic Model of the synthesis of a Secretory Protein (or a lysosomal enzyme) on an Membrane-Bound ribosome of the RER.

Role of GTP Hydrolysis in SRP and SRP Receptor Function

Only for General Knowledge

Only for General KnowledgeSchematic Model for the Synthesis of an Integral Membrane Protein

Only for General Knowledge Maintenance of Membrane Asymmetry

Only for General Knowledge Modifying the Lipid Composition of Membranes

Only for General KnowledgeSynthesis of the core portion of an N-linked oligosaccharide in the rough ER

Quality Control: Ensuring that Misfolded proteins do not proceed forward

Model of the Mammalian Unfolded Response UPR