@article{bd5c9690ec33480b9b8312f6c9fbb999,
title = "MSP1 encodes an essential RNA-binding pentatricopeptide repeat factor required for nad1 maturation and complex I biogenesis in Arabidopsis mitochondria",
abstract = "Mitochondrial biogenesis relies on nuclearly encoded factors, which regulate the expression of the organellar-encoded genes. Pentatricopeptide repeat (PPR) proteins constitute a major gene family in angiosperms that are pivotal in many aspects of mitochondrial (mt)RNA metabolism (e.g. trimming, splicing, or stability). Here, we report the analysis of MITOCHONDRIA STABILITY/PROCESSING PPR FACTOR1 (MSP1, At4g20090), a canonical PPR protein that is necessary for mitochondrial functions and embryo development. Loss-of-function allele of MSP1 leads to seed abortion. Here, we employed an embryo-rescue method for the molecular characterization of msp1 mutants. Our analyses reveal that msp1 embryogenesis fails to proceed beyond the heart/torpedo stage as a consequence of a nad1 pre-RNA processing defect, resulting in the loss of respiratory complex I activity. Functional complementation confirmed that msp1 phenotypes result from a disruption of the MSP1 gene. In Arabidopsis, the maturation of nad1 involves the processing of three RNA fragments, nad1.1, nad1.2, and nad1.3. Based on biochemical analyses and mtRNA profiles of wild-type and msp1 plants, we concluded that MSP1 facilitates the generation of the 3′ terminus of nad1.1 transcript, a prerequisite for nad1 exons a–b splicing. Our data substantiate the importance of mtRNA metabolism for the biogenesis of the respiratory system during early plant life.",
keywords = "3′-end processing, Arabidopsis, group II introns, mitochondria, MITOCHONDRIA STABILITY/PROCESSING PPR FACTOR1 (MSP1), pentatricopeptide (PPR) proteins, RNA metabolism, splicing",
author = "Corinne Best and Ron Mizrahi and Rana Edris and Hui Tang and Hagit Zer and {Colas des Francs-Small}, Catherine and Finkel, {Omri M.} and Hongliang Zhu and Small, {Ian D.} and Oren Ostersetzer-Biran",
note = "Funding Information: We thank Dr Etienne Meyer for providing the anti-Nad1 antibodies, Prof. Hans-Peter Braun for providing us laboratory procedures for BN-PAGE analysis, Stav Chen for assisting in immunoblots related to the analysis of MSP1, Prof. Ariel Chipman for his help with Nomarski microscopy analyses, and Dr Hakim Mireau for his help with MSP1-binding predictions and useful discussions regarding the role of MSP1 in mtRNA metabolism. A special thank goes to Prof. Gadi Schuster (Technion) for providing the PNPase enzyme and useful discussions regarding the MS, and Dr Michal Zmudjak, a former graduate student of OO-B, for her inspiring role in establishing the modified embryo-rescue method. This work was supported by grants to OO-B from the Israel Science Foundation (ISF) grants nos. 1834/20 and 3254/20, and by grants to HZ from the National Natural Science Foundation of China (NSFC; 32061143022). Funding Information: We thank Dr Etienne Meyer for providing the anti‐Nad1 antibodies, Prof. Hans‐Peter Braun for providing us laboratory procedures for BN‐PAGE analysis, Stav Chen for assisting in immunoblots related to the analysis of MSP1, Prof. Ariel Chipman for his help with Nomarski microscopy analyses, and Dr Hakim Mireau for his help with MSP1‐binding predictions and useful discussions regarding the role of MSP1 in mtRNA metabolism. A special thank goes to Prof. Gadi Schuster (Technion) for providing the PNPase enzyme and useful discussions regarding the MS, and Dr Michal Zmudjak, a former graduate student of OO‐B, for her inspiring role in establishing the modified embryo‐rescue method. This work was supported by grants to OO‐B from the Israel Science Foundation (ISF) grants nos. 1834/20 and 3254/20, and by grants to HZ from the National Natural Science Foundation of China (NSFC; 32061143022). Publisher Copyright: {\textcopyright} 2023 The Authors New Phytologist {\textcopyright} 2023 New Phytologist Foundation.",
year = "2023",
month = jun,
doi = "10.1111/nph.18880",
language = "English",
volume = "238",
pages = "2375--2392",
journal = "New Phytologist",
issn = "0028-646X",
publisher = "John Wiley & Sons",
number = "6",
}