Involvement of S6K1 in mitochondria function and structure in HeLa cells

Jisoo Park, Quangdon Tran, Kisun Mun, Kouhei Masuda, So Hee Kwon, Seon Hwan Kim, Dong-Hun Kim, George Thomas, Jongsun Park

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6 Citations (Scopus)

Abstract

The major biological function of mitochondria is to generate cellular energy through oxidative phosphorylation. Apart from cellular respiration, mitochondria also play a key role in signaling processes, including aging and cancer metabolism. It has been shown that S6K1-knockout mice are resistant to obesity due to enhanced beta-oxidation, with an increased number of large mitochondria. Therefore, in this report, the possible involvement of S6K1 in regulating mitochondria dynamics and function has been investigated in stable lenti-shS6K1-HeLa cells. Interestingly, S6K1-stably depleted HeLa cells showed phenotypical changes in mitochondria morphology. This observation was further confirmed by detailed image analysis of mitochondria shape. Corresponding molecular changes were also observed in these cells, such as the induction of mitochondrial fission proteins (Drp1 and Fis1). Oxygen consumption is elevated in S6K1-depeleted HeLa cells and FL5.12 cells. In addition, S6K1 depletion leads to enhancement of ATP production in cytoplasm and mitochondria. However, the relative ratio of mitochondrial ATP to cytoplasmic ATP is actually decreased in lenti-shS6K1-HeLa cells compared to control cells. Lastly, induction of mitophagy was found in lenti-shS6K1-HeLa cells with corresponding changes of mitochondria shape on electron microscope analysis. Taken together, our results indicate that S6K1 is involved in the regulation of mitochondria morphology and function in HeLa cells. This study will provide novel insights into S6K1 function in mitochondria-mediated cellular signaling.

Original languageEnglish
Pages (from-to)1904-1915
Number of pages12
JournalCellular Signalling
Volume28
Issue number12
DOIs
Publication statusPublished - 2016 Dec 1

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Keywords

  • Energy metabolism
  • Mitochondria fission
  • mTOR signaling
  • S6K1

ASJC Scopus subject areas

  • Cell Biology

Cite this

Park, J., Tran, Q., Mun, K., Masuda, K., Kwon, S. H., Kim, S. H., Kim, D-H., Thomas, G., & Park, J. (2016). Involvement of S6K1 in mitochondria function and structure in HeLa cells. Cellular Signalling, 28(12), 1904-1915. https://doi.org/10.1016/j.cellsig.2016.09.003