1. Molecular Biology & Medicine

2. a bacterial expression vector produces lots of the protein encoded by a cloned gene Figure 16.13

3. strategy for the production of a therapeutic protein Figure 16.14

4. Gleevec, designed atom by atom, is a treatment for CML p. 339

5. Medical Problems Accessible to Molecular Biology “One Gene - One Disease” –diseases due to single polypeptides enzymes of phenylalanine metabolism –alkaptonuria –phenylketonuria (PKU)

6. two defects in phenylalanine catabolism result in different heritable diseases Figure 17.1

7. Medical Problems Accessible to Molecular Biology “One Gene - One Disease” –diseases due to single polypeptides hemoglobin - a carrier protein –sickle cell disease –hemoglobin C disease –hemoglobin E disease

8. Figure 17.2

9. Figure 17.3

10. Medical Problems Accessible to Molecular Biology “One Gene - One Disease” –diseases due to single polypeptides membrane proteins - receptors & transporters –familial hypercholesterolemia –cystic fibrosis

11. Medical Problems Accessible to Molecular Biology “One Gene - One Disease” –diseases due to single polypeptides structural proteins –Duchenne muscular dystrophy »cells lack dystrophin –hemophilia »blood lacks coagulation protein

12. Medical Problems Accessible to Molecular Biology “One Gene - One Disease” –diseases due to single polypeptides misfolded protein –Transmissible spongiform encephalopathies, prion diseases »Scrapie, “mad cow”, Kruetzfeld- Jacob, kuru »transmitted by a protein

13. Figure 17.4 normalmisfolded

14. Medical Problems Accessible to Molecular Biology molecular analysis requires isolation of the affected gene(s) –human genomic libraries can be screened with sequence-specific probes deduced from protein sequence from mRNA from other species identified by a “positional” clue

15. sequences derived from genes or linked to genes can be used to isolate the genes Figure 17.6

16. RFLPs serve as natural genetic markers that can be linked to genes Figure 17.7

17. Heritable Diseases Arise by Mutation mutations result from a variety of causes –point mutations may be spontaneous or induced 5-methylcytosine => thymine mutations 5-m CAA or 5-m CAG =>TAA or TAG glutamine => stop 5-m CGA=>TGA arginine => stop

18. the uracil repair system does not recognize a 5-Me C=>T mutation Figure 17.8

19. Heritable Diseases Arise by Mutation mutations result from a variety of causes –point mutations may be spontaneous or induced silent - no disease missense - disease possible nonsense - disease probable

20. Heritable Diseases Arise by Mutation mutations result from a variety of causes –large-scale deletion may remove part of a gene all of a gene several neighboring genes –inversion or translocation may interrupt a gene create a new gene

21. a hybrid enzyme: part bcr (chr 22) and part abl (chr 9) an active protein Kinase p. 339

22. Heritable Diseases Arise by Mutation mutations result from a variety of causes –expanding triplet repeats may cause progressive heritable diseases Fragile-X syndrome  ~30 CGG repeats - normal  50-200 repeats - “premutated”  200-1300 repeats - cytosine methylation, gene inactivation, mental retardation

23. FMR1 promoter region Figure 17.9 18-162 bp 165-600 bp 600-6000 bp

24. Fragile-X at metaphase Figure 17.5

25. Heritable Diseases Arise by Mutation mutations result from a variety of causes –expanding triplet repeats may cause progressive heritable diseases Fragile-X syndrome - CGG repeats Myotonic dystrophy - CTG repeats Huntington’s disease - CAG repeats > 9 others, so far… – … or not

26. Molecular Diagnosis: Before the Disease genetically characterized diseases can be detected by various tests –phenotypic screens PKU preliminary screen

27. the heel-stick test identifies infants for more testing Figure 17.10

28. possible PKU bacteria that require phe grow on PKU blood, don’t on normal Blood Figure 17.10

29. detection of sickle cell allele by RFLP with a specific restriction enzyme Figure 17.11 MstII recognizes …CCTNAGG… The sickle cell allele has …CCTGTGG…

30. Molecular Diagnosis: Before the Disease genetically characterized diseases can be detected by various tests –phenotypic screens –genotypic screens identification of known disease-causing alleles –allele-specific RFLPs –allele-specific hybridization

31. detection of sickle cell allele by allele- specific hybridization Figure 17.12

32. Cancer - A Disease of Genetic Changes cancer cells differ from normal cells –division without normal signals to divide –division in spite normal signals not to divide

33. Cancer - A Disease of Genetic Changes tumor types differ –benign slow-growing, localized, like source tissue –malignant dedifferentiated cells

34. Figure 17.13

35. Cancer - A Disease of Genetic Changes tumor types differ –benign slow-growing, localized, like source tissue –malignant dedifferentiated cells –metastatic express digestive enzymes fail to make cell adhesion proteins cause vascularization

36. Cancer - A Disease of Genetic Changes tumor types differ –different tissues carcinomas: epithelial (lung, breast, colon, liver) sarcomas: deep tissues (bone, blood vessels, muscle) leukemias, lymphomas: blood stem cells

37. Viral agents in cancer Table 17.1

38. Cancer - A Disease of Genetic Changes varied causes –viruses (~15%) combined with specific mutations –most cancers (~85%) begin with somatic mutations dividing cells are most susceptible to mutational consequences

39. mutations in dividing cells produce mutant cell populations Figure 17.14

40. Cancer - A Disease of Genetic Changes two types of genes can lead to cancer –proto-oncogenes normally stimulate cell division –growth factors –growth factor receptors –signal transduction components –transcription factors usually dominant mutations

41. proto- oncogenes normally stimulate cell division Figure 17.15

42. Cancer - A Disease of Genetic Changes two types of genes can lead to cancer –tumor-suppressor genes normally regulate cell division –cell-adhesion proteins –DNA repair proteins –cell cycle control proteins generally recessive mutations

43. Figure 17.17

44. tumor-suppressor mutations are recessive Figure 17.16

45. Cancer - A Disease of Genetic Changes metastatic cancers involve the accumulation of many defects

46. five mutations of tumor suppressor genes or proto-oncogenes lead to polyp, benign tumor, class II & III adenomas, malignant tumor & metastatic cancer -TS APC +OG ras -TS DCC -TS p53 +telomerase, -adhesion, etc. Figure 17.18

47. cytotoxic treatments can be used to control the spread of cancer Figure 17.19

48. Treatment of Genetic Diseases modify the phenotype –restrict toxic substrates - PKU –metabolic inhibition - block cholesterol synthesis –kill targeted cells - treat cancer with chemicals that kill fast-growing cells –administer missing protein - insulin, clotting factor

49. example of ex vivo gene therapy Figure 17.20

50. Treatment of Genetic Diseases Gene Therapy –ex vivo remove cells from patient repair defect in cells return cells to patient but returned cells eventually die, so altered stem cells may serve as a permanent source of new cells

51. Treatment of Genetic Diseases Gene Therapy –in vivo repair cells in patient requires a delivery method –dispersal –gene delivery

52. Figure 17.22

53. Figure 17.23

54. many human genes are alternatively spliced Figure 17.24

55. rapid production of designer pharmaceuticals plant viral expression vectors –a host plant is infected with an engineered virus carrying a gene for a specific product –the same host species can produce protein from any gene placed in a viral vector –designer phamaceuticals are produced in months rather than years