TY - JOUR

T1 - One C-to-U RNA editing site and two independently evolved editing factors

T2 - testing reciprocal complementation with DYW-type PPR proteins from the moss Physcomitrium (Physcomitrella) patens and the flowering plants Macadamia integrifolia and Arabidopsis

AU - Oldenkott, Bastian

AU - Burger, Matthias

AU - Hein, Anke-Christiane

AU - Jörg, Anja

AU - Senkler, Jennifer

AU - Braun, Hans-Peter

AU - Knoop, Volker

AU - Takenaka, Mizuki

AU - Schallenberg-Rüdinger, Mareike

N1 - Funding Information: We dedicate this article to Axel Brennicke, who sadly passed away in February 2017. We thank Stefan Rensing (University Marburg, Germany) for providing the starting culture of P. patens ecotype Reute and to Lieven De Veylder (Ghent University, Belgium) for providing seeds of homozygous T-DNA insertion lines of Arabidopsis thaliana cwm1-1 and cwm1-2. We thank Bernd Reinken and the Botanical Garden Bonn for growing M. integrifolia. B.O., A.-C.H., V.K., and M.S.-R. thank Sarah Brenner for excellent technical assistance and the lab courses TRPL 2017/2018/ 2019 for their help in cloning overexpression constructs. M.B., A.J., and M.T. thank Dagmar Pruchner and Angelika Müller for excellent experimental help. B.O. and M.S.-R. thank Tobias Spanke for technical assistance with RStudio, Cloe De Luxán Hernández for comments on Arabidopsis culturing, and Ursula Mettmann and Ute Vothknecht for providing access to the binocular Leica MZ FLIII fluorescence stereomicroscope. J.S., H.-P.B., and M.S.-R. thank Michael Senkler for remodeling of complex I. Work on RNA editing and PPR proteins is supported by the Deutsche For-schungsgemeinschaft (grant SCHA1952/2-1 to M.S.-R.).

PY - 2020/7/2

Y1 - 2020/7/2

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85090505901&partnerID=8YFLogxK

U2 - 10.1105/tpc.20.00311

DO - 10.1105/tpc.20.00311

M3 - Article

C2 - 32616665

VL - 32

SP - 2997

EP - 3018

JO - The plant cell

JF - The plant cell

SN - 1040-4651

IS - 9

ER -