Journal of Life Science (생명과학회지)

Korean Society of Life Science (한국생명과학회)
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Developmental Expression of Eukaryotic Initiation Factor 4E (eIF4E) and eIF4E-binding Protein 1 (eIF4EBP1) in Rat Hippocampal Neurons

발생단계별 해마신경세포에서 eIF4E 및 eIF4EBP1의 표현

  • Park, Jaewan (Department of Anatomy, Dongguk University, College of Medicine, and Medical Institute of Dongguk University) ;
  • Moon, Il Soo (Department of Anatomy, Dongguk University, College of Medicine, and Medical Institute of Dongguk University)
  • 박재완 (동국대학교 의과대학 해부학교실) ;
  • 문일수 (동국대학교 의과대학 해부학교실)
  • Received : 2013.07.18
  • Accepted : 2013.07.26
  • Published : 2013.07.30
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Abstract

Local protein synthesis at subsynaptic sites plays a key role in the regulation of the protein composition in local domains. In this study, we carried out immunocytochemistry of cultured rat hippocampal neurons in various developmental stages to investigate the expression of eIF4E and its binding protein, eIF4EBP1. Both proteins were distributed in dendrites. In addition, eIF4EBP1 was highly expressed in the nucleus throughout the development, whereas eIF4E was not expressed in the nucleus. Punctate expression of eIF4E and eIF4EBP1 was evident in DIV 3. The colocalization rates of eIF4E or eIF4EBP1 puncta with PSD95 were higher in the dendrogenic than in the mature stages. In contrast, the colocalization rates of eIF4E and eIF4EBP1 puncta were higher in the mature than in the dendrogenic stages. As eIF4E is inactive when it is bound to eIF4EBP1, these data indicate that most dendritic eIF4E's are active during development but that they are mostly under inhibition in mature neurons.

신경세포의 가지돌기 내 단백질합성은 필요한 단백질을 실시간으로 제공할 수 있는 이점을 제공한다. 본 연구에서는 단백질합성인자 eIF4E와 그 억제 단백질인 eIF4EBP1의 발생단계별 표현을 배양한 해마신경세포를 면역 염색하여 조사하였다. eIF4E는 가지돌기에 점박이 모양으로 표현되었으며, 핵에는 표현되지 않았다. 그러나 eIF4EBP1는 가지돌기 뿐 아니라 발생초기(DIV 0.5)부터 핵에서 표현되었으며 성숙한 세포에서 핵에 더욱 뚜렷이 표현되었다. eIF4E 혹은 eIF4EBP1의 PSD95과의 colocalization은 $39.1{\pm}9.6%$ 및 $70.5{\pm}5.2%$ (DIV 7), $57.7{\pm}8.2%$ 및 $36.0{\pm}3.1%$ (DIV 10), $29.9{\pm}2.9%$ 및 $40.2{\pm}11.7%$ (DIV 20)이었다. eIF4E와 eIF4EBP1의 colocalizatin은 $18.5{\pm}2.6%$ (DIV 7), $11.1{\pm}3.9%$ (DIV 10), $38.6{\pm}5.6%$ (DIV 20)이었다. 이 결과는 eIF4E 및 eIF4EBP1의 많은 부분이 연접후에 위치하며, 발생초기에는 eIF4E가 활동적인 형태로 존재하지만, 성숙 신경세포에서는 eIF4EBP1과 결합하여 비활성적인 형태로 존재함을 의미한다.

Keywords

References

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