Profiling Glutathionylome in CD38-Mediated Epithelial-Mesenchymal Transition

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Protein S-glutathionylation is a key posttranslational modification regulating cellular functions.
• Epithelial-mesenchymal transition (EMT) is critical for development, healing, and cancer metastasis.
• CD38 overexpression induces EMT by reducing nicotinamide adenine dinucleotide (NAD+) levels.

Purpose of the Study:

• To characterize glutathionylome changes during EMT induced by CD38 overexpression.
• To identify proteins affected by S-glutathionylation in this context.
• To investigate the functional consequences of identified S-glutathionylation events.

Main Methods:

• Engineered a cell system expressing a glutathione synthetase (GS) mutant for clickable glutathione analogue profiling.
• Utilized azido-alanine to catalyze analogue formation for glutathionylome analysis.
• Quantified S-glutathionylated proteins and analyzed their involvement in EMT-related pathways.

Main Results:

• Identified 1298 glutathionylated proteins, with significant changes in EMT-associated pathways like adherens junction, actin cytoskeleton, and integrin signaling.
• Observed increased S-glutathionylation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in CD38-overexpressing cells.
• Demonstrated that S-glutathionylation at Cys63 of 15-PGDH reduces its enzymatic activity, promoting EMT via increased prostaglandin E2 (PGE2).

Conclusions:

• Clickable glutathione serves as an effective tool for comprehensive glutathionylome profiling.
• S-glutathionylation of 15-PGDH at Cys63 is a novel mechanism that inhibits its activity, thereby promoting EMT.
• These findings elucidate a new regulatory pathway linking S-glutathionylation, 15-PGDH activity, and EMT progression.