Acetylation-dependent coupling between G6PD activity and apoptotic signaling.

Area of Science:

• Biochemistry
• Molecular Biology
• Cellular Signaling

Background:

• Lysine acetylation is a widespread posttranslational modification in human proteins, including metabolic enzymes.
• Understanding acetylation's role is crucial for elucidating metabolic regulation and cellular communication.

Purpose of the Study:

• To investigate the functional impact of lysine acetylation on glucose-6-phosphate dehydrogenase (G6PD).
• To explore how G6PD acetylation influences its enzymatic activity, downstream modifications, and cellular processes like apoptosis.

Main Methods:

• Utilized site-specifically acetylated G6PD for functional analysis.
• Employed structural studies to elucidate mechanisms of acetylation-dependent inhibition.
• Investigated acetylation-dependent ubiquitylation, phosphorylation, and protein interactions.

Main Results:

• Acetylation at K89 activates G6PD, while acetylation at K403 inhibits it.
• Acetylation-induced G6PD inactivation involves structural distortion of the enzyme's active site.
• Demonstrated acetylation-dependent ubiquitylation (K95/97), phosphorylation (Y503), p53 interaction, and induction of apoptosis.

Conclusions:

• A single lysine acetylation site can coordinate multiple acetylation-dependent events.
• Acetylation is a complex posttranslational modification regulating enzymatic activity, further modifications, and apoptotic signaling pathways.