APEX-1 Regulates Cell Proliferation through GDNF/ GFRα1 Signaling = APEX-1은 GDNF/ GFRα1 시그널을 통해 세포증식을 조절한다

국문 초록 (Abstract)

APEX-1 (인간 apyrimidinic / apurinic 효소)은 염기성 사이트 및 DNA단일 가닥 결손으로 손상된 DNA을 복구 할 수 있는 다기능 단백질이다. 또한 APEX-1은 많은 전사 인자들의 redox-modifying factor (산화 환원 수정 요소)로서의 역할을 한다고 알려져 있다. 이런 APEX-1의 전사 타겟을 동정하는 것은 APEX-1의 다양한 세포 내 작용 메커니즘을 이해하는데 필수적이다. 따라서 이 논문에서는 먼저 Expression array analysis를 통해 glial cell-derived neurotropic factor receptor α1 (GFRα1)을 동정하였다. GFRα1은 glial cell-derived neurotropic factor (GDNF) family 수용체이며 APEX-1에 의해 발현이 증가된다. APEX-1이 과발현된 세포에서 GDNF처리에 의해GDNF/ GFRα1 시그널 타겟인 c-Src가 Tyr418잔기에서 인산화 됨을 관찰하였다. 또한 APEX-1이 과발현된 세포에 GDNF처리하면, 세포증식이 증가함을 보았다. 반면, APEX-1 발현을 siRNA을 이용하여 감소시키면 GFR α1 발현과 GDNF에 의한 c-Src 인산화 및 세포증식이 감소함을 확인하였다. 이상의 결과는 APEX-1은 GDNF/GFRα1 시그널을 통해 세포 생존과 증식을 조절함을 증명하였다. 따라서 본 연구를 통해 APEX-1의 세포 증식을 조절하는 새로운 기전을 규명하였다.

다국어 초록 (Multilingual Abstract)

Human apurinic/apyrimidinic endonuclease (APEX-1) is a multifunctional protein that is capable of repairing abasic sites and single-strand breaks in damaged DNA. In addition, it serves as a redox-modifying factor for a number of transcription factors. Identifying the transcriptional targets of APEX-1 is essential for understanding how it affects various cellular outcomes. Expression array analysis was used to identify glial cell-derived neurotropic factor receptor α1 (GFRα1), which is an encoding receptor for the glial cell-derived neurotropic factor (GDNF) family, the expression of which is induced by APEX-1. A target of GDNF/GFRα signaling, c-Src (Tyr418) was strongly phosphorylated by GNDF in the APEX-1 expressing cells. Moreover, GDNF initiated cell proliferation, measured by counting the number of cells, in the APEX-1 expressing cells. Importantly, the down-regulation of APEX-1 by siRNA caused a marked reduction in the GFRα1 expression level, and it reduced the ability of GDNF to phosphorylate c-Src (Tyr418) and stimulate cell proliferation. These results demonstrate an association between APEX-1 and GDNF/GFRα signaling and suggest a potential molecular mechanism for the involvement of APEX-1 in cell survival and proliferation.

목차 (Table of Contents)

• Introduction
• Materials and Methods
• Results Discussion
• References

참고문헌 (Reference)

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