Mitochondrial poly(ADP-ribosylation): from old data to new perspectives

Area of Science:

• Biochemistry and Molecular Biology
• Cellular Biology
• Genetics

Background:

• Poly(ADP-ribosylation) (PAR) is a post-translational modification vital for DNA repair, replication, transcription, and cell death.
• Historically, only one enzyme, ADPRT/PARP, was known, but a growing family of PARP enzymes has been identified.
• Emerging evidence indicates PAR is not limited to the nucleus, with cytoplasmic enzymes also active.

Purpose of the Study:

• To re-evaluate the existing literature on mitochondrial poly(ADP-ribosylation).
• To discuss the significance of mitochondrial PAR in the context of cell death.
• To integrate recent findings on PARP family members and cytoplasmic PARylation.

Main Methods:

• Literature review and reappraisal of existing studies on mitochondrial PARylation.
• Analysis of current research on the role of PAR in cell death pathways.
• Synthesis of data regarding nuclear and cytoplasmic PARylation activities.

Main Results:

• The discovery of multiple PARP enzymes introduces complexity to the field.
• Cytoplasmic PARylation suggests regulatory roles beyond the nucleus.
• Mitochondrial PARylation is an under-explored area with potential links to cell death.

Conclusions:

• The expanding PARP family and cytoplasmic PARylation necessitate a broader view of PAR's functions.
• Mitochondrial PARylation warrants further investigation for its role in cellular regulation and apoptosis.
• PARylation is a dynamic process with implications across various cellular compartments and functions, particularly in cell death.