Bacterial toxin RelE induces apoptosis in human cells

Area of Science:

• Microbiology
• Molecular Biology
• Cell Biology

Background:

• The bacterial protein RelE is a toxin component of the RelE-RelB toxin-antitoxin system, found ubiquitously in prokaryotes.
• RelE is known to inhibit prokaryotic translation and cell growth, potentially activated by nutritional stress.

Purpose of the Study:

• To investigate the activity of the bacterial RelE protein in eukaryotic cells.
• To determine if RelE exhibits toxicity beyond prokaryotes and to explore its mechanism of action.

Main Methods:

• Inducible expression of the Escherichia coli relE gene in a human osteosarcoma cell line.
• Observation of cell growth, viability, and induction of apoptosis.

Main Results:

• Expression of the E. coli relE gene in human cells significantly retarded cell growth.
• RelE induced cell death via apoptosis in the human osteosarcoma cell line.
• These findings suggest RelE possesses broad activity against both prokaryotic and eukaryotic cells.

Conclusions:

• Bacterial RelE toxin demonstrates significant toxicity and apoptotic activity in human eukaryotic cells.
• RelE's action on conserved translation machinery components may explain its broad prokaryotic and eukaryotic activity.
• RelE represents an unusual bacterial toxin with potential applications or implications in eukaryotic cell biology.