RNA aptamers for targeting mitochondria using a mitochondria-based SELEX method.

Area of Science:

• Biochemistry
• Molecular Biology
• Genomics

Background:

• Mitochondria play crucial roles in cellular energy production and signaling.
• Systematic Evolution of Ligands by Exponential Enrichment (SELEX) is a powerful technique for identifying nucleic acid ligands.
• Targeting mitochondria with specific ligands holds potential for therapeutic and diagnostic applications.

Purpose of the Study:

• To explore the feasibility of using mitochondria-based SELEX for aptamer discovery.
• To isolate and characterize RNA ligands that specifically bind to intact mitochondria.

Main Methods:

• Mitochondria were isolated from rat liver and their integrity confirmed using the respiratory control index.
• A 2'-F RNA random library was incubated with isolated mitochondria.
• Bound RNAs were selected, and counter-selection against nuclei was performed.
• Seven rounds of SELEX were conducted to enrich for mitochondrial-binding sequences.

Main Results:

• Two distinct RNA sequences, designated Mitomer1 and Mitomer2, were identified as binders to isolated mitochondria.
• Truncated Mitomer2 (short Mitomer2) demonstrated enhanced binding affinity to mitochondria compared to Mitomer1.
• The SELEX process successfully enriched for ligands with specificity for mitochondrial targets.

Conclusions:

• Mitochondria-based SELEX is an effective strategy for isolating specific RNA ligands against mitochondrial targets.
• The identified Mitomer sequences, particularly short Mitomer2, represent promising candidates for mitochondrial targeting applications.
• This study validates a novel approach for aptamer development directed at organelle-specific targets.