Research Progress in the Molecular Functions of Plant mTERF Proteins
Open Access
- 20 January 2021
- Vol. 10 (2), 205
- https://doi.org/10.3390/cells10020205
Abstract
Present-day chloroplast and mitochondrial genomes contain only a few dozen genes involved in ATP synthesis, photosynthesis, and gene expression. The proteins encoded by these genes are only a small fraction of the many hundreds of proteins that act in chloroplasts and mitochondria. Hence, the vast majority, including components of organellar gene expression (OGE) machineries, are encoded by nuclear genes, translated into the cytosol and imported to these organelles. Consequently, the expression of nuclear and organellar genomes has to be very precisely coordinated. Furthermore, OGE regulation is crucial to chloroplast and mitochondria biogenesis, and hence, to plant growth and development. Notwithstanding, the molecular mechanisms governing OGE are still poorly understood. Recent results have revealed the increasing importance of nuclear-encoded modular proteins capable of binding nucleic acids and regulating OGE. Mitochondrial transcription termination factor (mTERF) proteins are a good example of this category of OGE regulators. Plant mTERFs are located in chloroplasts and/or mitochondria, and have been characterized mainly from the isolation and analyses of Arabidopsis and maize mutants. These studies have revealed their fundamental roles in different plant development aspects and responses to abiotic stress. Fourteen mTERFs have been hitherto characterized in land plants, albeit to a different extent. These numbers are limited if we consider that 31 and 35 mTERFs have been, respectively, identified in maize and Arabidopsis. Notwithstanding, remarkable progress has been made in recent years to elucidate the molecular mechanisms by which mTERFs regulate OGE. Consequently, it has been experimentally demonstrated that plant mTERFs are required for the transcription termination of chloroplast genes (mTERF6 and mTERF8), transcriptional pausing and the stabilization of chloroplast transcripts (MDA1/mTERF5), intron splicing in chloroplasts (BSM/RUG2/mTERF4 and Zm-mTERF4) and mitochondria (mTERF15 and ZmSMK3) and very recently, also in the assembly of chloroplast ribosomes and translation (mTERF9). This review aims to provide a detailed update of current knowledge about the molecular functions of plant mTERF proteins. It principally focuses on new research that has made an outstanding contribution to unravel the molecular mechanisms by which plant mTERFs regulate the expression of chloroplast and mitochondrial genomes.Keywords
This publication has 72 references indexed in Scilit:
- The mTERF protein MOC1 terminates mitochondrial DNA transcription in the unicellular green alga Chlamydomonas reinhardtiiNucleic Acids Research, 2013
- Promoter-proximal pausing of RNA polymerase II: emerging roles in metazoansNature Reviews Genetics, 2012
- Structure of the human MTERF4–NSUN4 protein complex that regulates mitochondrial ribosome biogenesisProceedings of the National Academy of Sciences of the United States of America, 2012
- Plastid gene expression and plant development require a plastidic protein of the mitochondrial transcription termination factor familyProceedings of the National Academy of Sciences of the United States of America, 2011
- Transcription termination by nuclear RNA polymerasesGenes & Development, 2009
- RETRACTED: mTERF2 Regulates Oxidative Phosphorylation by Modulating mtDNA TranscriptionCell Metabolism, 2009
- A plant-specific RNA-binding domain revealed through analysis of chloroplast group II intron splicingProceedings of the National Academy of Sciences of the United States of America, 2009
- A Ribonuclease III Domain Protein Functions in Group II Intron Splicing in Maize ChloroplastsPlant Cell, 2007
- RNA editing in plant organelles: machinery, physiological function and evolutionCellular and Molecular Life Sciences, 2006
- SALT AND DROUGHT STRESS SIGNAL TRANSDUCTION IN PLANTSAnnual Review of Plant Biology, 2002