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Updated: Jun 19, 2026
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Generating iPS Cells from MEFS through Forced Expression of Sox-2, Oct-4, c-Myc, and Klf4
Published on: April 7, 2008
Klf4 interacts directly with Oct4 and Sox2 to promote reprogramming
Zong Wei1, Yang Yang, Peilin Zhang
1Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.
Stem Cells (Dayton, Ohio)
|October 10, 2009
Summary
Klf4, Oct4, and Sox2 directly interact to reprogram somatic cells into induced pluripotent stem (iPS) cells. This interaction is crucial for activating genes like Nanog and essential for successful cellular reprogramming.
Area of Science:
- Stem cell biology
- Molecular and cellular biology
- Epigenetics and gene regulation
Background:
- Somatic cell reprogramming into induced pluripotent stem (iPS) cells relies on specific transcription factors.
- Oct4, Sox2, and Klf4 are key factors in reprogramming, sharing target genes with embryonic stem (ES) cells.
- The precise functional relationship between Oct4, Sox2, and Klf4 during reprogramming remains incompletely understood.
Purpose of the Study:
- To investigate the interaction dynamics between Oct4, Sox2, and Klf4 during somatic cell reprogramming.
- To determine if these factors function collaboratively or independently in the reprogramming process.
- To elucidate the role of Klf4-Oct4-Sox2 interactions in activating key pluripotency genes.
Main Methods:
- Co-immunoprecipitation assays to detect protein-protein interactions between Klf4, Oct4, and Sox2.
- Analysis of endogenous protein interactions in iPS cells and mouse ES cells.
- Functional assays using dominant-negative Klf4 mutants to assess reprogramming efficiency.
- Chromatin immunoprecipitation (ChIP) to examine promoter occupancy of target genes like Nanog.
Main Results:
- Klf4 directly interacts with Oct4 and Sox2 at levels sufficient for iPS cell induction.
- Endogenous Klf4 forms complexes with Oct4 and Sox2 in both iPS cells and mouse ES cells.
- The C-terminal zinc finger region of Klf4 is essential for Oct4/Sox2 interaction and Nanog activation.
- Klf4 and Oct4 co-occupy the Nanog promoter, and Klf4 is critical for Nanog activation.
- A dominant-negative Klf4 mutant inhibits reprogramming by disrupting functional Oct4/Sox2/Klf4 complexes.
- Endogenous Klf4 interaction with Oct4/Sox2 is necessary for reprogramming even without Klf4 overexpression.
Conclusions:
- Direct physical interactions between Klf4, Oct4, and Sox2 are critical for efficient somatic cell reprogramming.
- Klf4's interaction domain and its role in Nanog activation are essential for pluripotency induction.
- These findings highlight a collaborative mechanism involving Oct4, Sox2, and Klf4 in establishing pluripotency.
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