Cell Bio 406 Lecture 8

  1. What is cell signaling?
    how a cell gives and receives messages to environment and with itself.
  2. Why is cell signaling necessary?
    cell survival depends on processing information.
  3. What is the more studied form of cell signaling?
    canonical WNT signaling
  4. What is a WNT ligand?
    protein that signals cell
  5. What is endocrine signaling?
    originate from far away from receiving cell
  6. What is paracrine signaling?
    signals from nearby cell
  7. What is autocrine signaling?
    originate from same cell.
  8. What is reception?
    signal detection occurs when ligand binds to receptor inside or outside cell
  9. What is transduction?
    relay of received signal
  10. What is response?
    final outcome of the received signal
  11. How are membrane receptors activated?
    dimerization and phosphorylation
  12. What are intracellular receptors?
    receptors inside cell that bind to small molecules that pass the plasma membrane
  13. Why is transduction multistep?
    permits signal amplification and enhanced regulation
  14. What is a second messenger?
    relays signal received by receptor
  15. What does kinase do?
  16. what does phosphotase do?
  17. What are the various responses to signaling pathways?
    • molecularly- changes gene expression and protein function
    • cellularly- cell proliferation, senescence, death and migration
  18. What are the parts of a receptor?
    lingand-binding domain and effector domain
  19. What does a silent antagonist do?
    makes ligand void
  20. What does a full agonist do?
    maximal biological resoponse
  21. what is a partial agonist?
    partial response
  22. What is inverse agonist?
    reduce activity
  23. What are essintial for signal transmission?
    modular interaction
  24. What are adaptors?
    consist of binding domains or motifs only.
  25. What is Grb2?
    growth factor receptor bound protein 2- adaptor with SH2 and SH3 to transduce EGFR signal
  26. What are adaptor proteins?
    link signaling molecules and target them in a manner that is responsive to extracellular signals.
  27. What is homologous desensitization?
    one feedback loop
  28. what is heterrologous desensitization?
    feedback loop effects two receptors
  29. How are activating and deactivating reactions controlled?
    by different regulatory proteins
  30. Why are activation and deactivation separate?
    allows for fine tuning of amplitude and timing.
  31. What are second messengers good for?
    quick diffusion within cell.
  32. What is a second messenger-stimulates protein kinase?
    tetramer of two C and two R subunits
  33. What do regulatory subunits do in PKA?
    inhibit C-catalytic
  34. What does R bind?
    cAMP molecules
  35. What happens when cAMP is highly concentrated?
    R dissociates rapidly
  36. What does Ca2+ do?
    serves as second messenger and regulatory molecule for calmodulin
  37. What controls concentraion of Ca2+?
    organellar sequestration and release
  38. What does Pl3-kinse do?
    regulates cell shape and activation of growth by phosophorylating lipids that change activity
  39. Where do nuclear receptors bind?
    to hormone response elements in the 5' UTR
  40. How is retinoic acid signals mediates?
    by nuclear receptors
  41. WHat are G=protein signaling modules?
    consist of a G-protein, receptor, and and effector protein to initiate diverse cell functions
  42. What controls heterotrimeric G proteins
    regulatory GTPase cycle
  43. When are heterotrimeric g proteins activated?
    When Ga subunit binds GTP
  44. What inactivates G protein?
    GTP hydrolysis to GDP
  45. What accelerates GTP hydrolysis?
    GAPs- GTPase-activating proteins.
  46. What are GAPs for g proteins?
    RGS and phospholipase C-bs
  47. When are GTP=binding proteins active?
    When bound to GTP
  48. What promotes activation?
    GEFs- guanine nucleotide exchange factors
  49. What promotes deactivatoin?
  50. What slows spontaneous nucleotide exhange?
    GDP dissociation inhibitors- GDIs
  51. Waht does Rho do?
    functions as a molecular switch
  52. What is key regulator of cell adhesion?
    Rho GTPases
  53. What increases accumulation of actin filaments to lateral walls of cells?
    Rac GTPases
Card Set
Cell Bio 406 Lecture 8
Cell signaling