Diseases and Drugs

Question 1

What disease does AZT treat and what is its mechamism of action?

Answer 1

HIV; inhibits reverse transcriptase

Question 2

What disease does acyclovir treat and what is its method of action?

Answer 2

Herpes; inhibits reverse transcriptase

Question 3

What is quinolone?

Answer 3

Broad-spectrum antibiotic; inhibits DNA gyrase and replication of DNA

Question 4

What is the cause of dyskeratosis congenita?

Answer 4

Telomerase deficiency syndrome; causes premature aging

Question 5

What is the cause of hereditary non-polyposis colorectal cancer (Lynch Syndrome)?

Answer 5

Mutations in MMR (mismatch repair) genes

Question 6

What is the cause of Hemoglobin Wayne syndrome?

Answer 6

Deletion of U frameshift/sense mutation that results in polypeptide elongation

Question 7

What is the cause of Thalassemias?

Answer 7

Mutation in beta-globin promoter or complete deletion of locus control region (LCR) of beta-globin gene cluster, resulting in lower levels of hemoglobin production in RBCs

Question 8

Describe Hemophilia B-Leyden.

Answer 8

Due to a mutation in promoter of Factor IX gene, important in blood clotting. After puberty, Factor IX production increases because androgen can alternatively bind the promoter.

Question 9

Describe Fragile X Syndrome.

Answer 9

Most common form of mental retardation in boys; results from CGG repeat expansion in 5’UTR of FMR1 gene, causing region to be highly methylated and preventing initiation of transcription.

Question 10

How does aspirin inhibit production of inflammatory cytokines?

Answer 10

Inhibits IKB phosphorylation, disallowing NF-kB from unbinding and moving into nucleus.

Question 11

Why does a congenital loss of APC increase the likelihood of developing colon cancer?

Answer 11

APC, a tumor suppressor, is part of the complex that degrades B-catenin. B-catenin is a TF to induce cell proliferation.

Question 12

How does Rifampicin work?

Answer 12

It binds RNA polymerase in bacteria and blocks the RNA exit channel.

Question 13

What is alpha-amanitin and what does it do?

Answer 13

Toxin/peptide of death-cap mushroom; prevents RNA Pol II from translocating by binding the bridge helix.

Question 14

What do Cockayne syndrome, Xeroderma Pigmentosum and Trichothiodystrophy have in common?

Answer 14

Involve mutations/loss of function in TFIIH, which is involved in transcriptional initiation and nucleotide excision repair. Common symptom is photosensitivity.

Question 15

How does Vorinostat work?

Answer 15

HDAC inhibitor used to treat T-cell lymphoma.

Question 16

What is Gleevac (imantinib)?

Answer 16

A tyrosine kinase inhibitor used to treat chronic mylogenous leukemia, a disease in which tyrosine kinase in permanently turned on.

Question 17

What is the molecular basis of Cystic Fibrosis?

Answer 17

F508 gene deletion resulting in misfolded CF transmembrane conductase regulator (CFTR), required to regulate sweat, mucus, and digestive fluids.

Question 18

Describe Methotrexate.

Answer 18

Competitive inhibitor of dihydrofolate reductase, an enzyme necessary for nucleotide biosynthesis; used in cancer treatment.

Question 19

How does penicillin work to block bacterial growth?

Answer 19

Irreversibly binds and inhibits glycopeptide transpeptidase and prevents cell wall formation.

Question 20

Describe Gout.

Answer 20

Due to accumulation of (low-soluble) purines in tissue. Leads to symptoms of arthritis, pain and welling in the joints (often big toe) due to increase in uric acid.

Question 21

Describe Lesch-Nyhan Disease.

Answer 21

An X-linked trait. A defect in the enzyme the breaks down purines, leading to accumulation in tissues. Leads to symptoms of gout and self-destructive biting

Question 22

Describe Cysplatin.

Answer 22

A chemotherapetuic alkylating agent. Causes crosslinks in DNA that are not remedies by repair mechanisms and lead to cell death.

Question 23

Describe Acyclovir.

Answer 23

A nucleoside analogue that is incorporated during replication and that then blocks DNA polymerase. An antiviral.

Question 24

Describe Adriamycin.

Answer 24

AKA doxorubicin, a chemotherapy drug; intercalates (inserts) between planar bases of DNA, inhibiting topoisomerase

Question 25

Describe Puromycin.

Answer 25

A nucleotide analogue that mimics tRNA acceptor region, allowing peptide transfer and premature termination of translation. An antibiotic.

Question 26

Describe spinal muscular atrophy.

Answer 26

Caused by defect in SNM1 gene that encodes for SMN protein (survival of motor neuron protein), which is an essential component of splicesomal machinery.

Question 27

Describe Erythromycin.

Answer 27

Antiobiotic; affects peptidyl transferase process of translation

Question 28

Describe Rapamycin.

Answer 28

mTOR protein-kinase inhibitor; kinase phosphorylates 4E-BP, prohibiting it from sequestering 4E, a binding protein of translation. A common immunosuppressant.

Question 29

Describe Craniosynostosis.

Answer 29

Causes premature fusion of cranial sutures; Proline to histidine substitution within MSX2 homeodomain causes stronger protein binding, “gain of function” mutation

Question 30

Describe Androgen-Insensitivity Syndrome.

Answer 30

Due to mutation in DNA binding domain of androgen receptor (a Zn-finger DNA binding protein)

Question 31

Describe Waardenburg Syndrome Type II.

Answer 31

A pigmentation anomaly due to mutation in MITF gene which encodes a bHLH binding protein, rendering the protein non-functional.

Question 32

Describe Rubinstein-Taybi Syndrome.

Answer 32

Characterized by short stature, broad fingers and toes. Due to mutation in CBP (a HAT co-activator) for many TFs.

Question 33

How does Tamoxifen work?

Answer 33

An estrogen antagonist prevents binding of estrogen to estrogen receptor, which then cannot dimerize and bind to DNA to recruit HATs.

Question 34

Describe Cyclosporin.

Answer 34

An immunosuppressant that inhibits calcineurin, a calcium-dependent kinase that acts on NF-AT, activating it to move into the nucleus to affect transcription of T-cells.

Question 35

What is the preferred secretase pathway of the APP (amyloid precursor protein)?

Answer 35

Alpha, then gamma. If beta, than gamma, protein is AB40 or AB42.

Question 36

Describe Prion Disease.

Answer 36

Due to misfolding of the prion protein into aggregates composed of a large proportion of beta-sheets.