TOR targets an RNA processing network to regulate facultative heterochromatin, developmental gene expression and cell...

Area of Science:

• Molecular Biology
• Cell Biology
• Genetics

Background:

• Cellular processes like proliferation and differentiation depend on precise gene expression control.
• Signaling pathways are crucial for regulating timely gene expression.

Purpose of the Study:

• To investigate the role of Tor2, the catalytic subunit of TORC1, in regulating gene expression.
• To elucidate the mechanism by which Tor2 controls the nuclear RNA elimination network.

Main Methods:

• Investigated the interaction between Tor2 and the Pir1 protein.
• Analyzed the impact of Tor2 phosphorylation on Pir1 stability.
• Examined the role of the ubiquitin-proteasome system (Ubi4, Cul4-Ddb1) in Pir1 degradation.
• Studied the effects on gene expression, heterochromatin assembly, and gametogenesis.

Main Results:

• Tor2 phosphorylation protects Pir1 from degradation by the ubiquitin-proteasome system.
• This pathway suppresses untimely and widespread gene expression, crucial for cell proliferation.
• Tor2-mediated RNA elimination dynamically regulates gene expression patterns during gametogenesis, including meiotic events.

Conclusions:

• The TORC1 pathway, via Tor2 and Pir1, controls gene expression through RNA decay and heterochromatin formation.
• This regulation is essential for cell proliferation and coordinating chromosomal events in gametogenesis.
• Dysregulation of this pathway may contribute to diseases like cancer.