<i>MISF2</i> Encodes an Essential Mitochondrial Splicing Cofactor Required for <i>nad2</i> mRNA Processing and Embryo Development in <i>Arabidopsis thaliana</i>
Mitochondria play key roles in cellular energy metabolism in eukaryotes. Mitochondria of most organisms contain their own genome and specific transcription and translation machineries. The expression of angiosperm mtDNA involves extensive RNA-processing steps, such as RNA trimming, editing, and the...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-02-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/5/2670 |
| Summary: | Mitochondria play key roles in cellular energy metabolism in eukaryotes. Mitochondria of most organisms contain their own genome and specific transcription and translation machineries. The expression of angiosperm mtDNA involves extensive RNA-processing steps, such as RNA trimming, editing, and the splicing of numerous group II-type introns. Pentatricopeptide repeat (PPR) proteins are key players in plant organelle gene expression and RNA metabolism. In the present analysis, we reveal the function of the <i>MITOCHONDRIAL SPLICING FACTOR</i> 2 gene (<i>MISF2</i>, <i>AT3G22670</i>) and show that it encodes a mitochondria-localized PPR protein that is crucial for early embryo development in <i>Arabidopsis</i>. Molecular characterization of embryo-rescued <i>misf2</i> plantlets indicates that the splicing of <i>nad2</i> intron 1, and thus respiratory complex I biogenesis, are strongly compromised. Moreover, the molecular function seems conserved between MISF2 protein in <i>Arabidopsis</i> and its orthologous gene (<i>EMP10</i>) in maize, suggesting that the ancestor of MISF2/EMP10 was recruited to function in <i>nad2</i> processing before the monocot–dicot divergence ~200 million years ago. These data provide new insights into the function of nuclear-encoded factors in mitochondrial gene expression and respiratory chain biogenesis during plant embryo development. |
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| ISSN: | 1661-6596 1422-0067 |