Cell Communication

1. Cell Communication Chapter 11

2. Common Mechanism • The same set of cell signaling mechanisms show up: 1. ___________ ___________ 2. _______ action • _______ ______ are mediated through a ___ ________ __________ ______ _______ ___________ _______ 3. _________ • ________ are responsible for _____ ______ ________ & ____________ ________ in allergic rxns 4. ___________ (Onco- means cancer) • ______ _________& Oncoproteins

3. Cell-to-Cell Communication • Critical for ________ organisms • Trillions of cells must ________ __ _______ ___ _________ ______ ________ • Recent research indicates: ______ results from _______ ___________ • On last year’s AP Exam • Also crucial for ____________________ ___________ __________________________________________________________________________________________

4. Recent Nobel Prizes in Medicine • 2001 – Hartwell, Hunt, & Nurse – _____ ________ and ____ _____ ________ (yeast) • 2002 – Brenner, Sulston, Horvitz – used C. elegans to elucidate the mechanism of __________ • 2006 – Fire & Mello - used C.elegans to discover the ________of ___ ___________ • 2007 – Capecchi, Evans, & Smithies – Hox genes & __________ ___________ ___________ • 2012 – Gurdon & Yamanaka - ______

8. Simon Sez… • Signaling is a lot like the game “Simon Says…” • The signal is received: the game players ____: “Simon says take a step forward” • The signal is transduced: players __________________ _________________________________________ • The signal elicits a response: players ____ ________if the command was preceded by “Simon says”

9. 3 Stages of Signaling • Thesis: external signals are received & converted to responses within the cell 1. Reception • Signaling molecule _____________________= Shape Change 2. Transduction • _________________________________________________ _______________________________________________ 3. Response • __________ of _____________ _______________________

10. ____ form of signaling • Yeast (fungi) mating • Saccharomycescerevisiae • Process: • ______ mating factor • ______complementary mating factor • ???? • _______: grow toward opp. type • _____ ____ = _______ ____________

11. Overview of Cell Signaling

12. View Animation • 11_06 SignalingOverview_A.swf

13. Reception • Reception involves __________________________ _______________________ • Only ______ ____have the _______ ______= only _________________________________ • Signaling molecule usually called ________ • ___________ binding causes a __________ change in the ____________ (remember induced fit?) • Conformational change = ______________________ ________________________________

14. 2 Types of Signal Receptors 1. ______ _________ Receptors • ___________ or __________ _______ or signal molecules • ________________________(GPCR) • ____________________ (RTK) • ___ _________ Receptors 2. ___________ Receptors  __________ or ________ ligands  ____________________________________

15. G Protein-Coupled Receptor

16. G-Protein Coupled Receptor • Common receptor • Found in ____________________________________ ___________________________________________ • Similarity between __________ and ________ evidences early evolution of G protein receptor molecules • Also responsible for ____________________________ _____________________________________________ • ____________ exert their influence by G protein pathways

17. G-Protein • All G Proteins have same basic structure • ________ spanning the membrane • Loops on either face of the membrane for ________ _____

18. G-Protein Pathways • We can explain how (Vibriocholerae) actually creates its symptoms • Cholera bacteria _________________________________ _______________________________________ • This G protein regulates _________ and ____ _________ • ____________________________________________ • So ____________________________________________ • __________________________________________________________________________________________ • Amplification? • Patients require _____________________________________ _________________ _________________________________

19. Receptor Tyrosine Kinase (RTK) • ___________ • Kinase = enzyme for _______ __ _________ ______

20. Ligand-Gated Ion Channel • Membrane receptor _____________________ _________________________________________ •  When the signal molecule binds, __________ ___________________ • Important in ____ _________ _________ • ______________ & ________ _________ • Could be _________________________ instead of ___________________________

21. IntracellularReceptor  __________ signal molecules  Testosterone  Most intracellular receptor signals do ___________________ _______________________  Testosterone behaving as a _____________ _______ -- controls ________________ ________________________

22. Questions 1. What are the 3 types of cell signaling? 2. What are the 3 stages of cell signaling? 3. What is the role of the “a” and “α” factors in yeast mating? 4. What happens when the “a” and “α” factors have been exchanged?

23. Questions (Page 2) • 1. 2 Types of Receptors • 2. What are the 3 Types of Membrane receptors? • 3. How does G-Protein coupled receptor differ from a Tyrosine kinase receptor? • 4. Which receptor is associated with steroid signaling molecules?

24. View Animation • 11_13SignalTransduction_A.swf

25. Transduction • ________ Pathway • Transduction = _______ _________ • Signal ___________ • Signal Transduction Pathways often involve a _____________ _________ • Molecule is phosphorylated = ________ • Phosphate removed = _____________

26. Protein Kinases (PK) -- enzymes that _______ _____________________ Protein Phosphatases (PP) -- enzymes that _______ _____________________

27. Protein Kinases • _____________ & ______________ of _______ is the primary mechanism of cellular activity regulation • __ __ ______ content codes for protein kinases • ________ _______ ______ leads to cancer • Protein ____________ • Enzymes that __________________________ • ________________________

28. Second Messengers • 1st messenger = ________ • Only _____ & ___ have 2nd messengers • Other important component of transduction pathways • Most components are __________ __ _________ • ___ ________ • ______ & _____ • ________ ____ & ______ ___ • Initiate a ____________ ________

29. Response • Response may occur in the _________ or __________ • 2 Types of typical response: 1. _________ _______ is regulated (turned on or off) 2. _________ __ _______ is regulated (promoted or inhibited)  Transcription Factors – _____________________ _______________________________________________

30. Transcription Factors

31. Signal Amplification • 2 Reasons for multistep pathways: 1. ______ _____________ 2. ________ of Cell Signaling • Signal Amplification • _______________________________________________ _______________________________________________ _______________________________________________

32. Signal Specificity • Different cells have different _______ • Different _______ ______ • Different _____ _______or __________ • Allows ________ ____ to have a _________ _______to the same signal • In Liver cells: Epinephrine = glycogen breakdown  glucose production • In cardiac muscle: Epinephrine = rapid & enhanced contractions

34. Scaffolding Proteins • Definition - ______ _____ proteins that __________________ ________________________ • Crucial for __________ _________ ________ ___________ • _______ ________ significantly increases efficiency of signal transfer • Scaffolding in ______ _____ hold together _________________ _________________________

36. Signal Termination • Just as certain molecules are ________, they too can be _________ • Signal molecule leaves the receptor = ____________ • _______ ____________ _________ phosphorylatedprotein kinases • Soon the _____ ____ is returned to its _____ form, and ____ __ __ _______again.

37. GF = Growth factor RTK = Receptor Tyrosine Kinase Ras = G Protein Associated with tumor growth Rho = G protein

38. RTK = Receptor Tyrosine Kinase GPCR – G-protein coupled receptor PDK1 = Protein dehydrogenase kinase Akt = Protein kinase -- Involved in apoptosis Apoptosis = Programmed cell death

39. 1. ______ 11. ______ 2. ______ 3. ______ 4. ______ 5. ______ 6. ______ 7. ______ 8. ______ 9. ______ 10. ______