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Mitosin/CENP-F as a negative regulator of activating transcription factor-4

Xubin Zhou1, Rong Wang, Libin Fan

  • 1Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.

The Journal of Biological Chemistry
|January 29, 2005
PubMed

Insights

Mitosin interacts with activating transcription factor-4 (ATF4), a key protein in cell processes. This study reveals mitosin acts as a negative regulator of ATF4 activity during the cell cycle.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Protein Interactions

Background:

  • Mitosin/CENP-F is a nuclear matrix protein involved in cell proliferation and differentiation.
  • Activating transcription factor-4 (ATF4) is a transcription factor crucial for proliferation, differentiation, and stress response.

Purpose of the Study:

  • To investigate the interaction between mitosin and ATF4.
  • To elucidate the functional consequences of this interaction on ATF4 activity.

Main Methods:

  • Co-immunoprecipitation assays to confirm protein-protein interactions.
  • Analysis of mitosin mutants for ATF4 binding domains.
  • Reporter gene assays to assess ATF4 transactivation activity.
  • Gene knockdown experiments to evaluate mitosin's regulatory role.

Main Results:

  • Mitosin directly binds to ATF4 via its C-terminal region, involving leucine zipper motifs.
  • ATF4 interacts with mitosin through its basic leucine zipper domain.
  • Mitosin represses ATF4 transactivation activity upon overexpression.
  • Mitosin knockdown enhances ATF4 activity.

Conclusions:

  • Mitosin negatively regulates ATF4 activity in interphase cells through direct physical interaction.
  • This interaction suggests a novel regulatory mechanism for ATF4 function in cellular processes.

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