1: Gene Expression

Question 1

Dysphagia

Answer 1

Difficulties in swallowing

Question 2

Dysphonia

Answer 2

Difficulty speaking

Question 3

Ptosis

Answer 3

Droopy eye lids

Question 4

Oculopharyngeal Muscular Dystrophy (OPMD)

Answer 4

Adult-Onset Myopathy:
Early features- ptosis, dysphagia, dysphonia
Later features- facial weakness, limited eye movement, proximal limb weakness (sometimes cannot walk)
Age of Onset: 40-50

Question 5

Coding Strand

Answer 5

Sense, non-template, same sequence as RNA (except U and T switch)

WE REPORT THIS TOP STRAND

Question 6

Template Strand

Answer 6

Non-coding, antisense, used by RNA polymerase to make RNA.

Question 7

Core Promoter Sequences

Answer 7

BRE (TFIIB recognition element)

TATA Box

Inr (initiation, defines +1)

DPE (downstream core promoter element)

Question 8

Transcription Initiation

Answer 8

1. Polymerase binds to promoter sequence in duplex DNA (closed complex).
2. Polymerase melts duplex DNA near transcription start site, forming bubble (open complex).
3. Polymerase catalyzes phosphodiester linkage of two initials rNTPs.

Question 9

Transcription Elongation

Answer 9

Polymerase goes 3’ to 5 ‘ down template strand, melting duplex DNA and adding rNTPsto growing RNA.

Question 10

Transcription Termination

Answer 10

At stop site, polymerase releases completed RNA and dissociates from DNA.

Question 11

Enhancer

Answer 11

Distal regulatory promoter element.

Question 12

Proximal Gene-Specific Regulatory Sites (examples)

Answer 12

GC

CCAAT

Question 13

Transcription Mediator Complex (Mediator)

Answer 13

Helps mostly distal but also proximal regulatory promoters interact with core promoter complex.

Question 14

Splice Signals

Answer 14

5’-splice site: AG|GU

3’-splice site: AG|G

Question 15

SnRNPs “Snurps”

Answer 15

Small nuclear ribonucleoprotein particles

U1/2/4/5/6

Guide the splicing reaction

Question 16

Lupus erythematosus

Answer 16

Chronic, inflammatory autoimmune disorder

Make antibodies to “Snurps”

Question 17

Zip Code Binding Proteins

Answer 17

Attach Specific mRNPs to Cytoskeletal Motor Proteins (microtubules and actin).

Question 18

Antibiotics that Inhibit Translation

Answer 18

Tetracycline: binds 30s subunit and inhibits binding of tRNAs

Chloramphenicol: inhibits peptidyl transferase on 50s subunit

Cycloheximide: inhibits translocation (eukaryotes)

Streptomycin: inhibits initiation and causes misreading of mRNA (prokaryotes)

Question 19

Regulation of mRNA Decay (stabile or labile)

Answer 19

AU-rich regions in mRNA 3’ UTR

Question 20

OPMD Mutation

Answer 20

Autosomal Dominant

100% Penetrant

Environmental factors make it worse

No gender preference

Question 21

OPMD Trinucleotide Repeat Expansion (on PABPN1 gene)

Answer 21

1-7 extra alanines

GCG (alanine) most common mutation in north NM and Hispanic populations

In the amino terminal coding region of the nuclear poly(A) binding protein

Question 22

Facial Muscles (differences from other muscles)

Answer 22

From neural crest of embryo

Always remodeling

Continuous repair may wear-out and might lose PABPN1 and interacting proteins