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Last Class: 1. Posttranscription regulation 2. Translation regulation 3. Cell membrane, phospholipids, cholesterol PowerPoint Presentation
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Last Class: 1. Posttranscription regulation 2. Translation regulation 3. Cell membrane, phospholipids, cholesterol

Last Class: 1. Posttranscription regulation 2. Translation regulation 3. Cell membrane, phospholipids, cholesterol

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Last Class: 1. Posttranscription regulation 2. Translation regulation 3. Cell membrane, phospholipids, cholesterol

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  1. Last Class: 1. Posttranscription regulation 2. Translation regulation 3. Cell membrane, phospholipids, cholesterol 4. Membrane protein, mobility, FRAP, FLIP

  2. Carbohydrate layer (Glycocalyx) on the cell surface Protecting the cell surface from mechanical and chemical damage Lymphocyte stained with ruthenium red

  3. Diagram of glycocalyx

  4. Summary membrane proteins and their anchoring models Methods to study membrane proteins, detergents diffusion, distribution, methods to study protein motion and distribution glycocalyx, proteoglycan

  5. Membrane Transport of Small Molecules and the Electrical Properties of Membranes

  6. Permeability of plasma membrane General principles I

  7. Permeability of plasma membrane General principles II Permeability coefficient (cm/sec)

  8. Membrane Transport Proteins Carrier Protein and Channel Protein

  9. Transportation Models Passive and Active Transport Electrochemical and concentration gradient, membrane potential Carrier proteins: passive and active Channels: always passive

  10. Electrochemical Gradient Is the combinatory effect of concentration gradient and membrane potentials

  11. Ionophores can serve as channels and carriers for ions Example: A23187, calcium permeabilizing agent

  12. Carrier Proteins and Active Membrane Transportation

  13. Conformational change of a carrier protein Mediates passive transport Change is spontaneous and random, so dependent on concentration

  14. Kinetics of simple and carrier-mediated diffusions

  15. 3 ways of driving active transportation utilizing passive carriers • Coupled carriers • ATP-driven pumps • Light-driven pumps

  16. 3 types of carrier-mediated transport Coupled carriers

  17. Coupled transportation of glucose and Na+ Cooperative binding of Na+ and glucose to the carrier. Outer surface, Na+ high concentration induces the high affinity of glucose to carrier

  18. Transcellular transport Tight junction separates apical and basal/lateral spaces Apical: glucose and Na+ coupling; basal/lateral: glucose is passive, Na+ maintained by ATP-driven pump

  19. Na+-K+ Pump, ATPase P-type transport ATPase (dependent on phosphorylation)

  20. Cycles of Na+-K+ Pump

  21. Calcium Pump ATP binding and hydrolysis can push calcium inside by bring N and P domain together

  22. A typical Ion Channel 1. selectivity, 2. Gated (close and open)

  23. The gating of Ion Channels

  24. The Structure of bacterial K+ channel Selectivity 10,000 fold over Na, although K+ 0.133nm, Na+ 0.095 nm

  25. The Selectivity of bacterial K+ channel Carbonyl oxygens at selective filter

  26. Gating Model of K+ channel Selectivity filter is fixed, the vestibule open and close like a diaphragm

  27. Summary • Membrane transportation, carrier protein, channel protein • Active transportation, passive transportation • Carrier Proteins, coupled carriers, ATPases, Na+-K+ Pump • Gating mechanisms of Ion Channels, K+ channel selectivity

  28. Intracellular Compartments and Protein Sorting

  29. The major intracellular compartments of an animal cell

  30. An electron micrograph of part of a live cell seen in cross section

  31. Hypothetical schemes for the evolutionary origins of organelles

  32. Topological relationships between compartments of the secretory and endocytic pathways in a eucaryotic cell

  33. A schematic roadmap of protein traffic Red: gated transport Blue: transmembrane transport Green: vesicular transport

  34. Vesicle budding and fusion during vesicular transport

  35. Two ways in which a sorting signal can be built into a protein • Signal sequence • Signal patch

  36. The transport of molecules between the nucleus and the cytosol

  37. The nuclear envelope

  38. The arrangement of nuclear pore complexes in the nuclear envelope

  39. Possible paths for free diffusion through the nuclear pore complex

  40. The function of a nuclear localization signal • Nuclear localization signal: NLS • Nuclear export signal: NES

  41. Nuclear import receptors

  42. The compartmentalization of Ran-GDP and Ran-GTP Ran-GAP: cytosol->Ran-GDP Ran-GEF: nucleus->Ran-GTP

  43. A model for how GTP hydrolysis by Ran provides directionality for nuclear transport

  44. A model for how Ran-GTP binding might cause nuclear import receptors to release their cargo

  45. The control of nuclear import during T-cell activation

  46. The endoplasmic reticulum