Vesicular transport

1
Vesicular transport
Dr. med. habil. Kohidai László Assoc.
Professor Depertment of Genetics, Cell- and
Immunoibiology Semmelwesi University 2008.
2
Intracellular vesicular transport

• Communication intracellular
• - cell-environment
• Membrane system
• Uptake of substances and transport to the place
  of digestion (lysosomes) - endocytosis
• Transport of proteins between ER-Golgi and to the
  surface membrane - exocitózis

3
Main pathways of vesicular transport
4
Intracellular vesicular transport

• Bidirectional, transport between compartment is
  balanced
• Continous recyclicling of membrane proteins

5
Pathway of biosynthetic- and secretory processes
Endocytosis
Recycling
6
Transport vesicles

• Membrane bounded vesicles filled with different
  cargos
• Secretion
• Lysosomal enzymes
• Components of surface membrane and the ECM
• Direction of transport is determined by the
  components of the membrane see donor and target
  compartments

7
(No Transcript)
8
Molecular bases of vesicular transport

• Biosynthetic-secretory and endocytotic pathways
  join 10 or more compartments
• Direction of the transport and fusion are
  determined by molecular matching (receptor/ligand)

9
Coated vesicles

• Role of the coat
• Components of the membrane (e.g. receptors) are
  concentrated into patches
• Removal of coated surfaces and formation of
  vesicles

10
Types of coated vesicles

• Clathrin-coated vesicles
• COPI-coated vesicles
• COPII-coated vesicles

Each type of vesicle has its own transport
11
We can distinguish the TEM morphology of the
three types of vesicles
12
Clathrin-coated vesicle Golgi surface
mamembrane transport
COPI- and COPII-coated vesicles rER - Golgi
transports
13
The building block of the clathrin-coat The
triskelion
14
Clathrin-coat Triskelion zikk-zakk and globular
structural elements
15
Comparison of clathrin composition
Light chain
Heavy chain
16
Protein-protein and protein-lipid associations
under clathrin coat
17
Clathrin binding proteins in Mammals
18
Releasing of clathrin-coated vesicles
Alberts et all. Molecular Biology of the cell
19
Receptor-mediated endocytosis
Role of dynamin in the process of vesicle release
Dynamin is a G-protein, it binds and cleaves GTP
Alberts et all. Molecular Biology of the cell
20
(No Transcript)
21
Receptor-mediated endocytosis
Alberts et all. Molecular Biology of the cell
22

Summary Clathrin-coated vesicule
23
Summary COPII-coated vesicle
24

Summary COPI-coated vesicle
25
Fusion of vesicle and target membrane (1)
26
Fusion of vesicle and target membrane (2)
NSF N-ethylmaleimide sensitive factor SNAP
soluble NSF attachment protein SNAP-25
synaptosomal associated protein 25 kDa VAMP
vesicle associated membrane protein
27
(No Transcript)
28
A significant component of the vesicle-membrane
fusion a protonpump
a subunit VPH1
d subunit VMA6
4c, c and c subunit VMA3, VMA11, VMA16
29
Association of main components in membrane fusion
SNAP-25 synaptosomal associated protein 25
kDa VAMP vesicle associated membrane protein
30
Vesicularis transport Budding
31
Vesicularis transport Docking
32
Kiss and run fusion
33
Subcellular distribution of SNARE proteins
SNARE soluble N-ethylmaleimide sensitive
factor attachment protein receptor
34
Role of G-proteins in vesicular trasport (1)
35
Rab-cycle
36
Role of G-proteins in vesicular trasport (2)
37
Number of genes responsible for vesicular
transport Phylogenetical approaches
38
Evolution of SNARE-s
S. cerevisiae
H. sapiens