Vesicular transport

1. Vesicular transport Dr. med. habil. Kőhidai 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

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

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

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. SNAP-25 VAMP Syntaxin n-Sec1 Syntaxin complex n-Sec1-syntaxin komplex 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. syntaxin VAMP SNAP-25 egyéb CCP – cl.-coated pit CCV – cl-coated vesic. DCV – dense core vesic. IC – intermed. comp. 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