Journal of Life Science (생명과학회지)

Korean Society of Life Science (한국생명과학회)
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Localization of Translation Initiation Factors to the Postsynaptic Sites

신경세포 연접후 위치에 단백질합성 해석시작인자(eIF)들의 존재

  • Choi, Myoung-Kwon (Department of Anatomy, College of Medicine, Dongguk University) ;
  • Park, Sung-Dong (Department of General Thoracic and Cardiovascular Surgery, College of Medicine, Dongguk University) ;
  • Park, In-Sick (Department of Anatomy, College of Oriental Medicine) ;
  • Moon, Il-Soo (Department of Anatomy, College of Medicine, Dongguk University)
  • 최명권 (동국대학교 의과대학 해부학교실) ;
  • 박성동 (동국대학교 의과대학 흉부외과학교실) ;
  • 박인식 (동국대학교 한의과대학 해부학교실) ;
  • 문일수 (동국대학교 의과대학 해부학교실)
  • Received : 2011.10.11
  • Accepted : 2011.11.17
  • Published : 2011.11.30
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Abstract

Local protein synthesis in neuronal dendrites is important for site-specific regulation of synaptic plasticity. In this study, we investigated whether translation initiation factors (eIFs) are present at the postsynaptic sites. High resolution confocal microscopy showed that the eIF4E and eIF4G (which bind the 5'-terminal mRNA cap), eIF5 (which is important during the 3' direction scanning to find an initiation codon), eIF6 (which mediates upregulation of translation by external stimuli), and eIF5A (which mediate translation upregulation under adverse conditions) were localized to the post-synaptic sites. Immunoblot and detergent extraction experiments also indicated that these eIFs were present in the synapse in association with the postsynaptic density (PSD). Our data provide evidence for the strategic positioning of eIFs at the postsynaptic site for initiation of translation in diverse situations.

신경세포의 연접후 위치에서 단백질합성은 국소적 연접가소성의 조절에 중요한 역할을 한다. 본 연구에서는 연접후 위치에 eIF들이 존재하는지를 배양한 흰쥐해마신경세포의 면역세포화학적 염색과 immunoblot, 그리고 세제세척실험으로 알아보았다. 단백질해석 시작단계의 초기에 중요한 역할을 하는 eIF4E와 eIF4G, 개시코돈을 찾는 단계에서 중요한 eIF5, 외부자극에 의하여 합성을 시작하게 하는 eIF6, 그리고 불리한 환경에서 해석의 효율을 높여주는 eIF5A 들은 모두 해마신경세포의 연접후에 위치함을 배양한 해마신경세포를 다중초점형광현미경으로 관찰할 수 있었다. 또한 Immunoblot 실험에서도 이들은 연접후치밀질(PSD) 분획에서 검출되었으며, 여러 가지 세제에 의하여 PSD로부터 잘 떨어지지 않는 것으로 보아 PSD와 강하게 결합하고 있음을 알 수 있었다. 본 연구결과는 여러 가지 eIF들이 연접후에 위치하여 다양한 상황에서 단백질합성을 시작하게 할 수 있음을 시사한다.

Keywords

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