KREPA6 functions in RNA editing catalytic complex structural organization and gRNA utilization in Trypanosoma brucei

Area of Science:

• Molecular Biology
• Parasitology
• Biochemistry

Background:

• Mitochondrial mRNA function in Trypanosoma brucei relies on RNA editing, a process guided by guide RNA (gRNA).
• RNA editing is catalyzed by three RNA Editing Catalytic Complexes (RECCs), each containing 12 proteins, including KREPA6.
• KREPA6 features an oligonucleotide binding (OB)-fold domain and an intrinsically disordered region (IDR).

Purpose of the Study:

• To investigate the functional significance of KREPA6 within the RECCs.
• To determine the impact of KREPA6 mutations on Trypanosoma brucei growth and RNA editing.

Main Methods:

• Site-directed mutagenesis of KREPA6, including single amino acid substitutions and IDR deletion.
• Assessment of parasite growth and viability.
• Analysis of RECC structure and RNA editing activity, including gRNA utilization.

Main Results:

• Single amino acid substitutions or IDR deletion in KREPA6 inhibit bloodstream form (BF) parasite growth and viability.
• Mutations affect RECC structure and alter, but do not abolish, RNA editing.
• Some mutations lead to differential gRNA utilization, suggesting complex functional roles for KREPA6.

Conclusions:

• KREPA6 plays multiple essential roles in Trypanosoma brucei, extending beyond its catalytic function.
• These roles involve dynamic interactions with other RECC proteins and substrate RNAs.
• Understanding KREPA6 function is crucial for deciphering the complex RNA editing process in these parasites.