Physical interaction of apoptosis-inducing factor with DNA and RNA

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Apoptosis-inducing factor (AIF) is a mitochondrial protein known to translocate to the nucleus during apoptosis.
• AIF possesses positively charged regions on its surface, facilitating DNA interaction.

Purpose of the Study:

• To investigate the molecular interactions of AIF with nucleic acids.
• To elucidate the role of AIF in the compaction of DNA and RNA during apoptosis.

Main Methods:

• Mass spectrometry to identify AIF-interacting proteins.
• In vitro binding assays with DNA and RNA.
• Electron microscopy to visualize AIF-nucleic acid complexes.
• Computational modeling to predict binding sites.

Main Results:

• AIF interacts with ribonucleoproteins, binding to the RNA moiety.
• AIF exhibits direct binding and condensation of both single-stranded and double-stranded DNA and RNA.
• Binding shows no clear sequence specificity, with NADP enhancing complex formation.
• AIF lacks detectable RNase activity.

Conclusions:

• AIF directly interacts with DNA and RNA, contributing to nucleic acid compaction in apoptotic cells.
• The binding mechanism involves a common site for distinct nucleic acid species.
• NADP plays a role in stabilizing higher-order AIF/nucleic acid complexes.