Jung-Eun Kim

Publications (2)11.46 Total impact

• Article: Proline-rich transcript in brain protein induces stress granule formation.

  Jung-Eun Kim, Incheol Ryu, Woo Jae Kim, Ok-Kyu Song, Jeongeun Ryu, Mi Yi Kwon, Joon Hyun Kim, Sung Key Jang
  [show abstract] [hide abstract]
  ABSTRACT: The repression of translation in environmentally stressed eukaryotic cells causes the sequestration of translation initiation factors and the 40S ribosomal subunit into discrete cytoplasmic foci called stress granules (SGs). Most components of the preinitiation complex, such as eIF3, eIF4A, eIF4E, eIF4G, and poly(A)-binding protein, congregate into SGs under stress conditions. However, the molecular basis of translation factor sequestration into SGs has not been clearly elucidated. Here, we report that proline-rich transcript in brain (PRTB) protein interacts with eIF4G and participates in SG formation. PRTB was recruited to SG under sodium arsenite and heat stress conditions. When overexpressed, PRTB inhibited global translation and formed SGs containing TIA-1, eIF4G, and eIF3. Knockdown of PRTB reduced the SG formation induced by sodium arsenite. These results suggest that PRTB not only is a component of SG formed by cellular stresses but also plays an important role in SG formation via an interaction with the scaffold protein eIF4G, which is associated with many translation factors and mRNAs.
  Molecular and cellular biology 02/2008; 28(2):803-13. · 6.06 Impact Factor
• Article: Translation of polioviral mRNA is inhibited by cleavage of polypyrimidine tract-binding proteins executed by polioviral 3C(pro).

  Sung Hoon Back, Yoon Ki Kim, Woo Jae Kim, Sungchan Cho, Hoe Rang Oh, Jung-Eun Kim, Sung Key Jang
  [show abstract] [hide abstract]
  ABSTRACT: The translation of polioviral mRNA occurs through an internal ribosomal entry site (IRES). Several RNA-binding proteins, such as polypyrimidine tract-binding protein (PTB) and poly(rC)-binding protein (PCBP), are required for the poliovirus IRES-dependent translation. Here we report that a poliovirus protein, 3C(pro) (and/or 3CD(pro)), cleaves PTB isoforms (PTB1, PTB2, and PTB4). Three 3C(pro) target sites (one major target site and two minor target sites) exist in PTBs. PTB fragments generated by poliovirus infection are redistributed to the cytoplasm from the nucleus, where most of the intact PTBs are localized. Moreover, these PTB fragments inhibit polioviral IRES-dependent translation in a cell-based assay system. We speculate that the proteolytic cleavage of PTBs may contribute to the molecular switching from translation to replication of polioviral RNA.
  Journal of Virology 04/2002; 76(5):2529-42. · 5.40 Impact Factor