A study on CTCF recruitment to damaged DNA sites
- 주제(키워드) CTCF , breast cancer , DNA repair
- 발행기관 아주대학교
- 지도교수 Jong Soo Lee
- 발행년도 2018
- 학위수여년월 2018. 8
- 학위명 석사
- 학과 및 전공 일반대학원 생명과학과
- 실제URI http://www.dcollection.net/handler/ajou/000000027897
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
In response to DNA damages, the ATM-Chk2 pathway is rapidly activated following by phosphorylating a number of proteins such γH2AX, Mre11-Rad50-Nbs1 (MRN) complex , p53 and BRCA1, which are involved in cell cycle arrest, apoptosis and DNA repair to maintain genomic integrity. CTCF has been demonstrated to participate in DNA damage repair in addition to various cellular progresses including transcription, insulation, and chromatin architecture but how CTCF is recruited into damaged DNA is still vague. In this study, I showed that recruitment and stable retention of CTCF into DNA lesions are dependent on Chk2 kinase activity but neither ATM kinase nor PARP activity. I also mutated five putative CHK2 phosphorylation serine/threonine to alanine residues in CTCF and evaluated recruitments of these CTCF mutants into damaged DNA sites using micro-irradiation. These putative un-phosphorylatable CTCF mutants are less recruited into the sites of damaged DNA, compared with its wild type In particular, ATM is required for CTCF accumulation at damaged DNA sites, although ATM kinase activity is not necessary. HP1γ and KAP-1 attendance into DNA double-strand break are dependent on CTCF. Finally, both N terminal and zinc finger domains are sufficient to CTCF accumulation on a damaged DNA line of the laser.
more목차
Abstract i
List of Figures iii
List of tables iv
INTRODUCTION 1
METHODS 3
Cell cultures, plasmids and siRNA 3
Immunoblot analysis 3
Site-directed mutagenesis 3
Immunofluorescence 4
Laser micro-irradiation 4
Antibody and inhibitor 4
Data analysis 5
RESULTS 7
1. CTCF participates in DNA damage sites induced by laser micro irradiation. 7
2. The recruitment of CTCF is inhibited into the DSBs in the presence of Chk2 inhibitor. 7
3. Mutation of variant predicted phosphorylation residues in CTCF by Chk2 are less recruited into DSB. 8
4. PARP inhibitor fail to prevent CTCF recruitment to DNA lesions. 9
5. CTCF is an interplay between ATM phosphorylation and KAP-1/HP1 interaction during DNA repair. 9
6. N terminus and zinc finger domains are responsible for CTCF accumulation at DNA damage sites. 10
CONCLUSION 24
REFERENCES 26
ACKNOWLEDGEMENTS 29
