Identification of Decrease in TRiC Proteins as Novel Targets of Alpha-Amanitin-Derived Hepatotoxicity by Comparative...

Area of Science:

• Toxicology
• Proteomics
• Molecular Biology

Background:

• Alpha-amanitin (α-AMA) is a potent cyclic peptide toxin from *Amanita phalloides* mushrooms.
• Hepatotoxicity is primarily attributed to α-AMA's inhibition of RNA polymerase II, affecting RNA and DNA translocation.

Purpose of the Study:

• To investigate novel molecular mechanisms of α-AMA-induced hepatotoxicity.
• To characterize the global proteome dynamics in response to α-AMA exposure in human hepatoma cells.

Main Methods:

• Quantitative nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS).
• Tandem mass tag (TMT) labeling for proteome-wide analysis.
• Bioinformatics analysis of quantified proteins.

Main Results:

• Identified 1828 proteins and quantified 1563 proteins in Huh-7 cells treated with α-AMA.
• Observed a dose-dependent decrease in four subunits of the T-complex protein 1-ring complex (TRiC/CCT).
• Characterized a unique toxic signature of α-AMA in hepatoma cells.

Conclusions:

• This study provides the first global proteomic analysis of α-AMA concentration variations.
• Findings suggest a novel mechanism of α-AMA-induced hepatotoxicity involving the T-complex protein 1-ring complex.
• The identified proteomic changes offer new molecular targets for understanding and potentially treating α-AMA poisoning.