1. Part II Structure and Catalysis
5 Amino Acids, Peptides, and Proteins
6 The Three-Dimensional Structure of Proteins
7 Protein Function
8 Enzymes
9 Carbohydrates and Glycobiology
10 Nucleotides and Nucleic Acids
11 Lipids
12 Biological Membranes and Transport
13 Biosignaling

2. Chapter 13
Biosignaling

3. Molecular Mechanisms of Signal Transduction

5. Scatchard Plot: Quantifies the Receptor-Ligand Interaction
R + L RL

6. Four general types of signal transducers

7. Gated Ion Channels Ion Channels Underlie Electrical Signaling in
Excitable Cells
Transmembrane
electrical potential

8. The Nicotinic Acetylcholine Receptor is a Ligand-Gated Ion Channels
CH3-N-CH2CH2O-C-CH3
CH3 O +

9. Voltage-Gated Ion Channels
Produce
Neuronal Action Potential
Neurons Have Receptor
Channels That Respond to
A Variety of Neurotransmitters
Glycine, glutamate, serotonin,
g-aminobutyric acid (GABA)

10. Receptor Enzymes
Tyrosine-
specific
protein
kinase

11. Regulation of gene expression by insulin

12. Activation of glycogen synthase by insulin

13. Guanylyl Cyclase is a Receptor Enzyme that Generates
The Second Messenger cGMP
(diarrhea)
cGMP-dependent protein kinase PKG
Atrial Natriuretic Factor
Heart
ANF
Kidney
ANF/ANFR
cGMP
Na+/H2O out

14. G protein-Coupled Receptors and Second Messengers
(Adrenaline)
Serpentine receptors
b-adrenergic receptor
Gs:
Stimulatory G protein
(a, b and g subunits)

15. Interaction of Gsa with adenylyl cyclase (AC)
Forskolin
GTP

16. Self-inactivation of Gs

17. Activation of cAMP-dependent protein kinase, PKA
ATP
PKI
a C subunit of PKA

19. Epinephrine Cascade

20. Degradation of cAMP by
Cyclic Nucleotide Phosphodiesterase

21. Desensitization of the b-Adrenergic Receptor
b-arrestin

22. Two Second Messengers Are Derived from PhosphatidylinositolsGq
Phospholipase C
(IP3)
Diacylglycerol (DG)
Protein kinase C (PKC)

24. Calcium Is a Second Messenger in Many Signal Transductions
Thymocytes (loaded with fura dye)
A single hepatocyte
norepinephrine
Cytosolic [Ca2+] < 10-7 M

25. Calmodulin (CaM)
CaM kinase II peptide

26. Sensory Transduction in Vision, Olfaction, and Gustation
Light reception in the vertebrate eye
(low levels of light)
(colors)
inner outer
segment
(visual cortex of the brain)

27. Light-induced hyperpolarization of rod cells
(Light induces degradation of cGMP)

28. Likely structure of rhodopsin complexed with G protein transducin
11-cis-retinal
opsin
(rhodopsin)
transducin
(abc subunits)

29. Molecular consequences of photon absorption by rhodopsin

30. Cone cells specialize in color vision – different opsins
Blindness
red- or green-
dichromats

31. Vertebrate Olfaction, and Gustation Use Mechanisms
Similar to the Visual System

33. Common features of signaling systems that detects
hormones, light, smells, and tetastes

34. Toxins produced by bacteria that cause cholera and
whooping cough (pertussis)

35. Regulation of Transcription by Steroid Hormons

36. Antagonist of steroid hormones as drugs
Antagonist of estrogen
- breast cancer treatment
Antagonist of progesterone
- terminate early pregnancies

37. Regulation of Cell Cycle by Protein Kinases
Eukaryotic
cell cycle

38. Activation of cyclin-dependent protein kinase (CDKs) by cyclin
and phosphorylation
T loop
(mask active site)
Glu51
CDK2
P-Thr
ATP

39. Variation in the activities of specific CDKs
during the cell cycle in animals

40. Regulation of CDK by phosphorylation and proteolysis
DBRP: destruction box
recognizing protein

41. Regulation of cell division by growth factors

42. Regulation of passage from G1 to S by phosphorylation of pRb
pRb, retinoblastoma protein

43. Oncogenes, Tumor Suppressor Genes, and Programmed Cell Death
Oncogenes are mutant forms of the genes for protein that regulate the cell cycle
Conversion of a regulatory gene into a viral oncogene

44. Oncogene-encoded defective EGF receptor
Breast, stomach, and ovary cancers

45. From Normal Epithelial Cell to Colorectal Cancer

46. Initial events of apoptosis