KRBP72 facilitates ATPase-dependent editing progression through a structural roadblock in mitochondrial A6 mRNA
Ontology highlight
ABSTRACT: Uridine insertion/deletion editing of mitochondrial mRNAs in kinetoplastids entails the coordinated action of three complexes. RNA Editing Catalytic Complexes (RECCs) catalyze the enzymatic reactions, while the RNA Editing Substrate Binding Complex (RESC) and RNA Editing Helicase 1 Complex coordinate interactions between RECCs, mRNAs, and hundreds of gRNAs that direct edited sequences. Additionally, numerous auxiliary factors are required for productive editing of specific mRNAs. Here, we elucidate the role of KRBP72, an editing auxiliary factor of the ABC ATPase family that exhibits RNA binding activity. In procyclic form T. brucei, KRBP72 knockdown leads to a pause in editing at the base of a predicted stem loop structure in ATP synthase subunit 6 (A6) mRNA. Enhanced cross-linking and affinity purification revealed KRBP72 binding sites both within and upstream of this stem loop. KRBP72 ATPase activity is essential for its A6 mRNA editing function; however, its RNA binding activity is dispensable. KRBP72 interacts with most RESC proteins in an RNA-dependent manner. By contrast, RESC12A associates with KRBP72 in an RNA-independent fashion, and RESC12A strongly promotes KRBP72’s interaction with RNA. Hence, KRBP72 ATPase activity facilitates the progression of editing through a challenging RNA secondary structure, highlighting this protein’s crucial role in A6 mRNA editing.
ORGANISM(S): Trypanosoma brucei brucei
PROVIDER: GSE272305 | GEO | 2025/01/29
REPOSITORIES: GEO
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