RNA Editing in Plants and Its Evolution

Abstract

RNA editing alters the identity of nucleotides in RNA molecules such that the information for a protein in the mRNA differs from the prediction of the genomic DNA. In chloroplasts and mitochondria of flowering plants, RNA editing changes C nucleotides to U nucleotides; in ferns and mosses, it also changes U to C. The approximately 500 editing sites in mitochondria and 40 editing sites in plastids of flowering plants are individually addressed by specific proteins, genes for which are amplified in plant species with organellar RNA editing. These proteins contain repeat elements that bind to cognate RNA sequence motifs just 5' to the edited nucleotide. In flowering plants, the site-specific proteins interact selectively with individual members of a different, smaller family of proteins. These latter proteins may be connectors between the site-specific proteins and the as yet unknown deaminating enzymatic activity.

Predictable Alteration of Sequence Recognition by RNA Editing Factors from Arabidopsis

“…PLS-class proteins contain characteristic triplets of P, L (35 to 36 amino acids in length), and S (31 amino acids) motifs (Lurin et al, 2004). The PLS-class proteins commonly have extra C-terminal domains that are implicated in RNA editing (Lurin et al, 2004), an alteration of specific bases in the RNA sequence that is essential for correct expression of many organellar transcripts (reviewed in Chateigner-Boutin and Small, 2010;Takenaka et al, 2013b). The process requires PPR proteins to convey the necessary RNA specificity by binding in close proximity to the cytidine that will be edited (Okuda and Shikanai, 2012).…”

Dysfunctional mitochondria regulate the size of root apical meristem and leaf development in Arabidopsis

“…3 In general, the P subfamily PPR proteins are involved in RNA cleavage, splicing, stabilization and translation, whereas members of the PLS subfamily are mostly associated with RNA editing in chloroplasts and mitochondria. 3,4 Computational prediction and crystal structure analysis reveal that PPR proteins may bind RNA via a one PPR domain-one nucleotide module. 1,5 Therefore, the diverse array of PPR motifs may constitute a sequence-specific RNA binding protein.…”

The Pentatricopeptide Repeat Proteins TANG2 and ORGANELLE TRANSCRIPT PROCESSING439 Are Involved in the Splicing of the Multipartite nad5 Transcript Encoding a Subunit of Mitochondrial Complex I

“…They are characterized by tandem repeats of a 35-amino acid motif (Small and Peeters, 2000) and classified according to the type of motifs they bear: members of the P subfamily are composed of the canonical 35-residue motif, while the PLS subfamily is composed of trimers of motifs of various lengths and additional C-terminal domains (Lurin et al, 2004). The P-class PPR proteins have been shown to be involved in transcript stability and intron splicing, while most PLS proteins are implicated in RNA editing (Takenaka et al, 2013;Barkan and Small, 2014).…”