Transfer of plastid RNA-editing activity to novel sites suggests a critical role for spacing in editing-site recognition

AUTOR(ES)

Hermann, Marita

FONTE

The National Academy of Sciences

RESUMO

RNA editing in higher plant plastids alters mRNA sequences by C-to-U conversions at highly specific sites through an unknown mechanism. To elucidate how the cytidine residues to be edited are specifically recognized and distinguished from other cytidines in close proximity, we have changed in vivo the distances of two plastid RNA-editing sites from their essential upstream cis-acting sequence element. Analysis of RNA editing in transgenic chloroplasts revealed that reduction of this distance by 1 nt entirely abolishes RNA editing. Surprisingly, deletions or combinations of deletional and point mutations that shift a heterologous cytidine residue in the same distance from the upstream cis-element as the editing site in the wild type result in transfer of the RNA-editing activity to the heterologous cytidine whereas the wild-type site remains unedited. Our results suggest that the molecular identity of at least some editing sites in the chloroplast genome is defined by their distance from an essential upstream sequence element.

Documentos Relacionados

• Adenosine deaminases acting on RNA (ADARs): RNA-editing enzymes
• Synthetic substrate analogs for the RNA-editing adenosine deaminase ADAR-2.
• Site-selective inhibition of plastid RNA editing by heat shock and antibiotics: a role for plastid translation in RNA editing.
• RNA-editing cytidine deaminase Apobec-1 is unable to induce somatic hypermutation in mammalian cells
• The structure of a yeast RNA-editing deaminase provides insight into the fold and function of activation-induced deaminase and APOBEC-1