Bio 103 Lecture

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Bio 103 Lecture 9READINGSVesicular
Traffic 17 701-715Golgi 17 715-727

• Vesicular Traffic I
• Golgi Apparatus

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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• Transport from ER through Golgi
• Transport from Golgi (TGN) to lysosomes
• Glycosylation of proteins in Golgi
• Organization of Golgi and models for the
  directional transport of proteins

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Protein Sorting - Golgi

• Introduction to the Golgi Apparatus

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16-1 Overview of major protein-sorting pathways
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Red arrows biosynthetic-secretory
pathways Green arrows endocytic pathways Blue
arrows Retrieval pathways
13-3 (Alberts) Intracellular compartments
involved in the biosynthetic-secretory and
endocytic pathways
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Red arrows biosynthetic-secretory
pathways Green arrows endocytic pathways Blue
arrows Retrieval pathways
13-1 Alberts Biosynthetic-secretory and
endocytic pathways
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Protein Sorting to Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• -Transport vesicles form from coated regions of
  membranes
• -Coat functions
• Concentrates transport proteins into patches
• Induce patches to vesicularize
• -Types coats
• COPII ER to Golgi
• COPI Golgi to Golgi, Golgi back to ER
• Clathrin Trans-Golgi Network (TGN), endocytosis
• -Proteins essential to vesicle function
• Monomeric GTPases control coat assembly
• EXAMPLE Coat-recruitment GTPases
• ARFs (responsible for COPI and clathrin coat
  assembly)
• Sar1 (responsible for COPII coat assembly)
• SNARE proteins guide vesicles (mediate vesicle
  fusion?)
• Rab proteins ensure specificity of vesicle docking

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13-22 (Alberts) The Golgi Apparatus
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13-2 Transport vesicles bud from one compartment
and fuse with another
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17-7 Mechanism of vesicle budding and fusion
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17-8 EM of an in vitro budding reaction
involving COPII and liposomes
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13-5 (Alberts) Utilization of different coats in
vesicular traffic
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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• -Transport vesicles form from coated regions of
  membranes
• -Coat functions
• -Types coats
• -Proteins essential to vesicles
• Monomeric GTPases control coat assembly
• SNARE proteins guide vesicles (mediate vesicle
  fusion?)
• Rab proteins ensure specificity of vesicle
  docking
• Transport from ER through Golgi
• -Proteins leave ER in COPII-coated vesicles
• -Resident ER proteins have to be retreived from
  Golgi
• Resident ER membrane protein retrieval signal
  KKXX
• Resident ER soluble protein retrieval signal
  KDEL

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17-9 Role of Sar1 in assembly and disassembly of
COPII coats
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17-11 Model for docking and fusion of transport
vesicles with their target membranes
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17-14 Vesicle-mediated protein trafficking
between ER and Golgi
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13-21a (Alberts) Model for the retrieval of ER
resident proteins
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13-21b (Alberts) Model for the retrieval of ER
resident proteins
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17-18 Involvement three major coat proteins in
vesicular trafficking
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17-19 Structure of clathrin coats
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EM of clathrin cages
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13-8 (Alberts) Assembly and disassembly of the
clathrin coat
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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• Transport from ER through Golgi
• Transport from Golgi (TGN) to lysosomes

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17-23 Trafficking of soluble lysosomal enzymes
from TGN and cell surface to lysosomes
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13-31 (Alberts) Lysosomes and their components
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13-35 (Alberts) Three pathways to degradation in
lysosomes
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13-37a (Alberts) Transport of newly synthesized
lysosomal hydrolases to the lysosome
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13-37a (Alberts) Transport of newly synthesized
lysosomal hydrolases to the lysosome
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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• Transport from ER through Golgi
• Transport from Golgi (TGN) to lysosomes
• Glycosylation of proteins in Golgi

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13-28 (Alberts) Histochemical stain showing the
biochemical compartmentalization of the Golgi
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13-29 The functional compartmentalization of the
Golgi
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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• Transport from ER through Golgi
• Transport from Golgi (TGN) to lysosomes
• Glycosylation of proteins in Golgi
• Organization of Golgi and models for the
  directional transport of proteins

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13-30 Two possible models explaining the
organization of the Golgi Apparatus and the
transport of proteins from one cisternae to the
next
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Protein Sorting - Golgi

• Introduction to Golgi
• Molecular mechanisms of vesicular trafficking
• -Transport vesicles form from coated regions of
  membranes
• -Coat functions
• -Types coats
• -Proteins essential to vesicles
• Monomeric GTPases control coat assembly
• SNARE proteins guide vesicles (mediate vesicle
  fusion?)
• Rab proteins ensure specificity of vesicle
  docking
• Transport from ER through Golgi
• -Proteins leave ER in COPII-coated vesicles
• -Resident ER proteins have to be retreived from
  Golgi
• Resident ER membrane protein retrieval signal
  KKXX
• Resident ER soluble protein retrieval signal
  KDEL
• Transport from Golgi (TGN) to lysosomes
• Glycosylation of proteins in Golgi
• Organization of Golgi and models for the
  directional transport of proteins