2. Academic Validation
  3. Serine 347 Phosphorylation by JNKs Negatively Regulates OCT4 Protein Stability in Mouse Embryonic Stem Cells

Serine 347 Phosphorylation by JNKs Negatively Regulates OCT4 Protein Stability in Mouse Embryonic Stem Cells

  • Stem Cell Reports. 2017 Dec 12;9(6):2050-2064. doi: 10.1016/j.stemcr.2017.10.017.
Ki Beom Bae 1,  Dong Hoon Yu 1,  Kun Yeong Lee 1,  Ke Yao 1,  Joohyun Ryu 1,  Do Young Lim 1,  Tatyana A Zykova 1,  Myoung Ok Kim 2,  Ann M Bode 1,  Zigang Dong 3
Affiliations

Affiliations

  • 1 The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA.
  • 2 The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA; The School of Animal BT Science, Kyungpook National University, Sangju, Gyeongsangbuk-do 37224, Republic of Korea.
  • 3 The Hormel Institute, University of Minnesota, 801 16(th) Avenue NE, Austin, MN 55912, USA. Electronic address: zgdong@hi.umn.edu.
PMID: 29153991 DOI: 10.1016/j.stemcr.2017.10.017
Abstract

The POU transcription factor OCT4 is critical for maintaining the undifferentiated state of embryonic stem cells (ESCs) and generating induced pluripotent stem cells (iPSCs), but its precise mechanisms of action remain poorly understood. Here, we investigated the role of OCT4 phosphorylation in the biological functions of ESCs. We observed that c-Jun N-terminal kinases (JNKs) directly interacted with and phosphorylated OCT4 at serine 347, which inhibited the transcriptional activity of OCT4. Moreover, phosphorylation of OCT4 induced binding of FBXW8, which reduced OCT4 protein stability and enhanced its proteasomal degradation. We also found that the mutant OCT4 (S347A) might delay the differentiation process of mouse ESCs and enhance the efficiency of generating iPSCs. These results demonstrated that OCT4 phosphorylation on serine 347 by JNKs plays an important role in its stability, transcriptional activities, and self-renewal of mouse ESCs.

Keywords

FBXW8; JNK; OCT4; embryonic stem cells; induced pluripotent stem cells; phosphorylation; self-renewal; ubiquitination.

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