One C-to-U RNA editing site and two independently evolved editing factors

testing reciprocal complementation with DYW-type PPR proteins from the moss Physcomitrium (Physcomitrella) patens and the flowering plants Macadamia integrifolia and Arabidopsis

authored by

Bastian Oldenkott, Matthias Burger, Anke-Christiane Hein, Anja Jörg, Jennifer Senkler, Hans-Peter Braun, Volker Knoop, Mizuki Takenaka, Mareike Schallenberg-Rüdinger

Abstract

Cytidine-to-uridine RNA editing is a posttranscriptional process in plant organelles, mediated by specific pentatricopeptide repeat (PPR) proteins. In angiosperms, hundreds of sites undergo RNA editing. By contrast, only 13 sites are edited in the moss Physcomitrium (Physcomitrella) patens. Some are conserved between the two species, like the mitochondrial editing site nad5eU598RC. The PPR proteins assigned to this editing site are known in both species: the DYW-type PPR protein PPR79 in P. patens and the E1-type PPR protein CWM1 in Arabidopsis (Arabidopsis thaliana). CWM1 also edits sites ccmCeU463RC, ccmBeU428SL, and nad5eU609VV. Here, we reciprocally expressed the P. patens and Arabidopsis editing factors in the respective other genetic environment. Surprisingly, the P. patens editing factor edited all target sites when expressed in the Arabidopsis cwm1 mutant background, even when carboxy-terminally truncated. Conversely, neither Arabidopsis CWM1 nor CWM1-PPR79 chimeras restored editing in P. patens ppr79 knockout plants. A CWM1-like PPR protein from the early diverging angiosperm macadamia (Macadamia integrifolia) features a complete DYW domain and fully rescued editing of nad5eU598RC when expressed in P. patens. We conclude that (1) the independently evolved P. patens editing factor PPR79 faithfully operates in the more complex Arabidopsis editing system, (2) truncated PPR79 recruits catalytic DYW domains in trans when expressed in Arabidopsis, and (3) the macadamia CWM1-like protein retains the capacity to work in the less complex P. patens editing environment.

Organisation(s)

Section Plant Molecular Biology and Plant Proteomics

External Organisation(s)

Ulm University
University of Bonn
Kyoto University

Type

Article

Journal

The plant cell

Volume

32

Pages

2997-3018

No. of pages

22

ISSN

1040-4651

Publication date

02.07.2020

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Plant Science, Cell Biology

Electronic version(s)

https://doi.org/10.1105/tpc.20.00311 (Access: Closed)