CCR4-NOT is required for suppressing pervasive transcription and retrotransposable elements.

Area of Science:

• Molecular Biology
• Gene Regulation
• Epigenetics

Background:

• The CCR4-NOT complex is crucial for gene regulation, with known roles in mRNA decay.
• Its nuclear functions, particularly in transcription, remain largely uncharacterized in humans.

Purpose of the Study:

• To investigate the nuclear functions of the CCR4-NOT complex in gene transcription.
• To understand the role of CNOT1 and CNOT4 subunits in transcriptional regulation.

Main Methods:

• Used auxin-induced degradation to deplete CNOT1 and CNOT4 subunits.
• Employed transient transcriptome profiling (TT-Seq) to analyze global RNA synthesis changes.
• Investigated the impact on KRAB-Zinc-Finger-protein (KZNF) gene expression and retrotransposable element (rTE) activation.

Main Results:

• Depletion of CNOT1 or CNOT4 caused widespread RNA synthesis activation in genic and intergenic regions.
• Decreased expression of KZNF genes correlated with the activation of rTEs, particularly LINEs.
• Activated transcription events were predominantly located near KZNF binding sites.
• CCR4-NOT complex was shown to regulate rTE RNA stability, controlling transposon expression.

Conclusions:

• The CCR4-NOT complex plays a significant role in suppressing both genic and rTE transcription, partly via KZNF regulation.
• The complex tightly controls transposon expression by repressing transcription and degrading rTE RNAs.