DNA Repair

Question 1

Defects in HRR typically cause which two things?

Answer 1

1. Breast Cancer
2. Ataxia Telangiatcia

Question 2

Defect in MMR causes______

Answer 2

Lynch Syndrome

Question 3

Defects in NER Trans Pathway causes ______

Answer 3

Cockaynes

Question 4

How severe is the Mental Disabilty for Werner Syndrome?

Answer 4

No Mental Retardation, No Neurological Effects!

Question 5

BER 3 Steps

Answer 5

1. ID with Glycosylase/helicase
2. Cut with Apurinic Endonuc
3. Patch up with PLL

“Sugar Surgery Keeps it short and Sweet”

Question 6

Defects in ssBR cause_____

Answer 6

Ataxia Oculomotor Apraxia

Question 7

NER Trans 4 Steps

Answer 7

1. ID with CSA/CSB/Ubiquitination
2. Clean and Chop with recruit of XPA
3. Single Chops with XPA, (XPF,ERcc1, XPG)complex
4. Patch with PolD/E and Ligase

Question 8

NHEJR in 3 Steps

Answer 8

1. ID/Sense with Ku70/80
2. Align/Chop with Artemis
3. Ligate

Question 9

NER Global 3 Steps

Answer 9

1. ID with XPC/XPE
2. Single Chops with XPA, (XPF,ERcc1, XPG)complex
3. Patch up with HPL

“You need eXperienCe and Energy to fix the globe”

Question 10

3 things different AOMA vs Ataxia Telangiectasia

Answer 10

1. Telang is HRR repair, AOMA is ssBR repair
2. AT has cancer risk, AOMA does not
3. Ataxia Tenlagiectasia has dilated blood vessels around face

Question 11

ssBR in 3 Steps

Answer 11

1. ID with PARP-1 and recruit XRCC4 Scaffold
2. Process and Fix with APTX
3. Insert and Glue with DNA Pol B

Question 12

7 Steps In depth Nucleotide Excision Repair Mechanism

Answer 12

1. During DNA transcription, helix distortion/damage will halt RNA polymerase attempting to transcribe the DNA. The damage and halted RNA Pol is recognized by two proteins - CSA and CSB.
2. RNA Pol is displaced from the transcription site.
3. XPA, XPC, and TFIIH is recruited to the site
4. XPF and XPG then make incisions 3’ and 5’ of the damage
5. XPB and XPD, which have helicase activity, unwind the DNA to allow release of the damaged section. This step is also aided by TFIIH
6. DNA Pol (∂/ε) fill the gap
7. DNA Ligase then repairs the nick

Question 13

MMR 3 steps

Answer 13

1. ID with MSH2/6
2. Cut with MLH1/PMS2
3. Remove and Patch with HEP3L

“Start off with two sets of MH’s for Mismatch”

Question 14

Homologous Recombination Repair in 3 Steps

Answer 14

1. ID/Sense with Rad52/51 (BRCA regulation)
2. Nuclease,Heli,Join​

Question 15

Defects in NER Global Pathway causes______

Answer 15

Xeroderma Pig (Cancer)

Question 16

Defects in BER causes______

Answer 16

Werner’s Syndrome