Post-transcriptional control of executioner caspases by RNA-binding proteins

Area of Science:

• Molecular Biology
• Cell Biology
• Genetics

Background:

• Caspases are crucial for apoptosis, with regulation occurring at multiple levels.
• Post-transcriptional control of caspases remains less understood.
• RNA-binding proteins (RBPs) play diverse roles in gene expression regulation.

Purpose of the Study:

• To investigate the role of RBPs in post-transcriptional regulation of caspases.
• To identify specific RBPs controlling caspase expression in C. elegans and humans.
• To elucidate the mechanisms of translational repression of caspases.

Main Methods:

• RNA-binding protein identification and characterization in C. elegans.
• Analysis of mRNA translation and 3' UTR binding sites.
• Investigation of caspase regulation in human cell lines.

Main Results:

• Four conserved RBPs (PUF-8, MEX-3, GLD-1, CGH-1) sequentially repress CED-3 caspase in C. elegans.
• GLD-1 represses CED-3 mRNA translation via its 3' UTR, providing dual apoptosis control.
• Homologs of these RBPs, including PUM1, QKI, and DDX6, regulate human caspase-3.

Conclusions:

• RBPs provide critical post-transcriptional control over executioner caspases.
• Translational repression of caspases by RBPs is a conserved mechanism for apoptosis regulation across metazoans.
• This finding highlights a widespread strategy for controlling programmed cell death.