scholarly journals The rice pentatricopeptide repeat protein PPR756 is involved in pollen development by affecting multiple RNA editing in mitochondria

2019 ◽  
Author(s):  
Qiannan Zhang ◽  
Yanghong Xu ◽  
Jishuai Huang ◽  
Kai Zhang ◽  
Haijun Xiao ◽  
...  
Keyword(s):  
Rna Editing ◽  
Pollen Development ◽  
Target Genes ◽  
Large Family ◽  
Loss Of Function ◽  
Pentatricopeptide Repeat ◽  
Knock Out ◽  
Ppr Protein ◽  
Ppr Proteins ◽  
Sterile Pollen

AbstractIn land plants, the pentatricopeptide repeat (PPR) proteins form a large family involved in post-transcriptional processing of RNA in mitochondria and chloroplasts, which is critical for plant development and evolutionary adaption. Although studies showed a number of PPR proteins generally influence the editing of organellar genes, few of them were characterized in detail in rice. Here, we report a PLS-E subclass PPR protein in rice, PPR756, loss of function of which led to the abolishment of RNA editing events among three mitochondrial genes including atp6, ccmC, and nad7. Their defective C-to-U transformation then resulted in improper amino acid retention which could cause abortive pollen development. Furthermore, PPR756 could bind to the three target genes directly and interact with three OsMORFs (multiple organellar RNA editing factors): OsMORF1, OsMORF8-1, and OsMORF8-2. The knock-out plants of PPR756 exhibited retarded growth and greener leaves during the early vegetative stages, along with sterile pollen and lower seed setting at the reproductive stage. These results established a role for PPR756 in rice development, participating in RNA editing of three various transcripts and cooperating with OsMORFs via an editosome manner in rice.

scholarly journals The DYW-subgroup pentatricopeptide repeat protein PPR27 interacts with ZmMORF1 to facilitate mitochondrial RNA editing and seed development in maize

2020 ◽  
Vol 71 (18) ◽  
pp. 5495-5505 ◽  
Author(s):  
Rui Liu ◽  
Shi-Kai Cao ◽  
Aqib Sayyed ◽  
Huan-Huan Yang ◽  
Jiao Zhao ◽  
...  
Keyword(s):  
Rna Editing ◽  
Seed Development ◽  
Plant Mitochondria ◽  
Endosperm Development ◽  
Complex Iii ◽  
Mitochondrial Rna ◽  
Mitochondrial Complex ◽  
Pentatricopeptide Repeat ◽  
Ppr Protein ◽  
Ppr Proteins

Abstract C-to-U RNA editing in plant mitochondria requires the participation of many nucleus-encoded factors, most of which are pentatricopeptide repeat (PPR) proteins. There is a large number of PPR proteins and the functions many of them are unknown. Here, we report a mitochondrion-localized DYW-subgroup PPR protein, PPR27, which functions in the editing of multiple mitochondrial transcripts in maize. The ppr27 mutant is completely deficient in C-to-U editing at the ccmFN-1357 and rps3-707 sites, and editing at six other sites is substantially reduced. The lack of editing at ccmFN-1357 causes a deficiency of CcmFN protein. As CcmFN functions in the maturation pathway of cytochrome proteins that are subunits of mitochondrial complex III, its deficiency results in an absence of cytochrome c1 and cytochrome c proteins. Consequently, the assembly of mitochondrial complex III and super-complex I+III2 is decreased, which impairs the electron transport chain and respiration, leading to arrests in embryogenesis and endosperm development in ppr27. In addition, PPR27 was found to physically interact with ZmMORF1, which interacts with ZmMORF8, suggesting that these three proteins may facilitate C-to-U RNA editing via the formation of a complex in maize mitochondria. This RNA editing is essential for complex III assembly and seed development in maize.

scholarly journals The novel E-subgroup pentatricopeptide repeat protein DEK55 is responsible for RNA editing at multiple sites and for the splicing of nad1 and nad4 in maize

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ru Chang Ren ◽  
Xu Wei Yan ◽  
Ya Jie Zhao ◽  
Yi Ming Wei ◽  
Xiaoduo Lu ◽  
...  
Keyword(s):  
Rna Editing ◽  
Rna Processing ◽  
Mitochondrial Gene ◽  
Endosperm Development ◽  
Molecular Evidence ◽  
Pentatricopeptide Repeat ◽  
Reading Frame ◽  
Maize Kernel ◽  
Ppr Protein ◽  
Ppr Proteins

Abstract Background Pentatricopeptide repeat (PPR) proteins compose a large protein family whose members are involved in both RNA processing in organelles and plant growth. Previous reports have shown that E-subgroup PPR proteins are involved in RNA editing. However, the additional functions and roles of the E-subgroup PPR proteins are unknown. Results In this study, we developed and identified a new maize kernel mutant with arrested embryo and endosperm development, i.e., defective kernel (dek) 55 (dek55). Genetic and molecular evidence suggested that the defective kernels resulted from a mononucleotide alteration (C to T) at + 449 bp within the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within the mitochondria. Molecular analyses showed that the editing percentage of 24 RNA editing sites decreased and that of seven RNA editing sites increased in dek55 kernels, the sites of which were distributed across 14 mitochondrial gene transcripts. Moreover, the splicing efficiency of nad1 introns 1 and 4 and nad4 intron 1 significantly decreased in dek55 compared with the wild type (WT). These results indicate that DEK55 plays a crucial role in RNA editing at multiple sites as well as in the splicing of nad1 and nad4 introns. Mutation in the DEK55 gene led to the dysfunction of mitochondrial complex I. Moreover, yeast two-hybrid assays showed that DEK55 interacts with two multiple organellar RNA-editing factors (MORFs), i.e., ZmMORF1 (Zm00001d049043) and ZmMORF8 (Zm00001d048291). Conclusions Our results demonstrated that a mutation in the DEK55 gene affects the mitochondrial function essential for maize kernel development. Our results also provide novel insight into the molecular functions of E-subgroup PPR proteins involved in plant organellar RNA processing.

scholarly journals Non-canonical Features of Pentatricopeptide Repeat Protein-Facilitated RNA Editing in Arabidopsis Chloroplasts

2019 ◽  
Author(s):  
Yueming Kelly Sun ◽  
Bernard Gutmann ◽  
Ian Small
Keyword(s):  
Rna Editing ◽  
Plant Mitochondria ◽  
Pentatricopeptide Repeat ◽  
Site Specific ◽  
Ppr Protein ◽  
Sequence Variations ◽  
Ppr Proteins ◽  
Editing Activity ◽  
Chloroplast Rna ◽  
Plant Organelles

AbstractCytosine (C) to uracil (U) RNA editing in plant mitochondria and chloroplasts is facilitated by site-specific pentatricopeptide repeat (PPR) editing factors. PPR editing factors contain multiple types of PPR motifs, and PPR motifs of the same type also show sequence variations. Therefore, no PPR motifs are invariant within a PPR protein or between different PPR proteins. This work evaluates the functional diversity of PPR motifs in CHLOROPLAST RNA EDITING FACTOR 3 (CREF3). The results indicate that previously overlooked features of PPR editing factors could also contribute to RNA editing activity. In particular, the N-terminal degenerated PPR motifs and the two L1-type PPR motifs in CREF3 are functionally indispensable. Furthermore, PPR motifs of the same type in CREF3 are not interchangeable. These non-canonical features of CREF3 have important implications on the understanding of PPR-facilitated RNA editing in plant organelles.

scholarly journals Maize Defective Kernel605 Encodes a Canonical DYW-Type PPR Protein that Edits a Conserved Site of nad1 and Is Essential for Seed Nutritional Quality

2020 ◽  
Vol 61 (11) ◽  
pp. 1954-1966 ◽  
Author(s):  
Kaijian Fan ◽  
Yixuan Peng ◽  
Zhenjing Ren ◽  
Delin Li ◽  
Sihan Zhen ◽  
...  
Keyword(s):  
Nutritional Quality ◽  
Complex I ◽  
Endosperm Development ◽  
Mitochondrial Rna ◽  
Loss Of Function ◽  
Pentatricopeptide Repeat ◽  
Respiratory Pathway ◽  
Ppr Protein ◽  
Normal Seed ◽  
Ppr Proteins

Abstract Pentatricopeptide repeat (PPR) proteins involved in mitochondrial RNA cytidine (C)-to-uridine (U) editing mostly result in stagnant embryo and endosperm development upon loss of function. However, less is known about PPRs that are involved in farinaceous endosperm formation and maize quality. Here, we cloned a maize DYW-type PPR Defective Kernel605 (Dek605). Mutation of Dek605 delayed seed and seedling development. Mitochondrial transcript analysis of dek605 revealed that loss of DEK605 impaired C-to-U editing at the nad1-608 site and fails to alter Ser203 to Phe203 in NAD1 (dehydrogenase complex I), disrupting complex I assembly and reducing NADH dehydrogenase activity. Meanwhile, complexes III and IV in the cytochrome pathway, as well as AOX2 in the alternative respiratory pathway, are dramatically increased. Interestingly, the dek605 mutation resulted in opaque endosperm and increased levels of the free amino acids alanine, aspartic acid and phenylalanine. The down- and upregulated genes mainly involved in stress response-related and seed dormancy-related pathways, respectively, were observed after transcriptome analysis of dek605 at 12 d after pollination. Collectively, these results indicate that Dek605 specifically affects the single nad1-608 site and is required for normal seed development and resulted in nutritional quality relevant amino acid accumulation.

scholarly journals The Amount of RNA Editing Sites in Liverwort Organellar Genes Is Correlated with GC Content and Nuclear PPR Protein Diversity

2019 ◽  
Vol 11 (11) ◽  
pp. 3233-3239 ◽  
Author(s):  
Shanshan Dong ◽  
Chaoxian Zhao ◽  
Shouzhou Zhang ◽  
Hong Wu ◽  
Weixue Mu ◽  
...  
Keyword(s):  
Rna Editing ◽  
Phylogenetic Diversity ◽  
Gc Content ◽  
Pentatricopeptide Repeat ◽  
Protein Coding ◽  
Protein Diversity ◽  
Ppr Protein ◽  
Ppr Proteins ◽  
Codon Positions ◽  
Positive Correlations

Abstract RNA editing occurs in the organellar mRNAs of all land plants but the marchantioid liverworts, making liverworts a perfect group for studying the evolution of RNA editing. Here, we profiled the RNA editing of 42 exemplars spanning the ordinal phylogenetic diversity of liverworts, and screened for the nuclear-encoded pentatricopeptide repeat (PPR) proteins in the transcriptome assemblies of these taxa. We identified 7,428 RNA editing sites in 128 organellar genes from 31 non-marchantioid liverwort species, and characterized 25,059 PPR protein sequences. The abundance of organellar RNA editing sites varies greatly among liverwort lineages, genes, and codon positions, and shows strong positive correlations with the GC content of protein-coding genes, and the diversity of the PLS class of nuclear PPR proteins.

scholarly journals A synthetic RNA editing factor edits its target site in chloroplasts and bacteria

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Santana Royan ◽  
Bernard Gutmann ◽  
Catherine Colas des Francs-Small ◽  
Suvi Honkanen ◽  
Jason Schmidberger ◽  
...  
Keyword(s):  
Rna Editing ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Target Sequence ◽  
Pentatricopeptide Repeat ◽  
Binding Assays ◽  
E Coli ◽  
Ppr Protein ◽  
Ppr Proteins

AbstractMembers of the pentatricopeptide repeat (PPR) protein family act as specificity factors in C-to-U RNA editing. The expansion of the PPR superfamily in plants provides the sequence variation required for design of consensus-based RNA-binding proteins. We used this approach to design a synthetic RNA editing factor to target one of the sites in the Arabidopsis chloroplast transcriptome recognised by the natural editing factor CHLOROPLAST BIOGENESIS 19 (CLB19). We show that our synthetic editing factor specifically recognises the target sequence in in vitro binding assays. The designed factor is equally specific for the target rpoA site when expressed in chloroplasts and in the bacterium E. coli. This study serves as a successful pilot into the design and application of programmable RNA editing factors based on plant PPR proteins.

scholarly journals OTP970 Is Required for RNA Editing of Chloroplast ndhB Transcripts in Arabidopsis thaliana

Genes ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 139
Author(s):  
Mei Fu ◽  
Xiaona Lin ◽  
Yining Zhou ◽  
Chunmei Zhang ◽  
Bing Liu ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Rna Editing ◽  
Nadh Dehydrogenase ◽  
Loss Of Function ◽  
Pentatricopeptide Repeat ◽  
B Subunit ◽  
Transcript Processing ◽  
Organelle Genomes ◽  
Ppr Proteins ◽  
Rna Immunoprecipitation

RNA editing is essential for compensating for defects or mutations in haploid organelle genomes and is regulated by numerous trans-factors. Pentatricopeptide repeat (PPR) proteins are the prime factors that are involved in RNA editing; however, many have not yet been identified. Here, we screened the plastid-targeted PLS-DYW subfamily of PPR proteins belonging to Arabidopsis thaliana and identified ORGANELLE TRANSCRIPT PROCESSING 970 (OTP970) as a key player in RNA editing in plastids. A loss-of-function otp970 mutant was impaired in RNA editing of ndhB transcripts at site 149 (ndhB-C149). RNA-immunoprecipitation analysis indicated that OTP970 was associated with the ndhB-C149 site. The complementation of the otp970 mutant with OTP970 lacking the DYW domain (OTP970∆DYW) failed to restore the RNA editing of ndhB-C149. ndhB gene encodes the B subunit of the NADH dehydrogenase-like (NDH) complex; however, neither NDH activity and stability nor NDH-PSI supercomplex formation were affected in otp970 mutant compared to the wild type, indicating that alteration in amino acid sequence is not necessary for NdhB function. Together, these results suggest that OTP970 is involved in the RNA editing of ndhB-C149 and that the DYW domain is essential for its function.

scholarly journals GmPGL2, Encoding a Pentatricopeptide Repeat Protein, Is Essential for Chloroplast RNA Editing and Biogenesis in Soybean

2021 ◽  
Vol 12 ◽  
Author(s):  
Xingxing Feng ◽  
Suxin Yang ◽  
Yaohua Zhang ◽  
Cheng Zhiyuan ◽  
Kuanqiang Tang ◽  
...  
Keyword(s):  
Rna Editing ◽  
Pentatricopeptide Repeat ◽  
Mobility Shift ◽  
Single Nucleotide ◽  
Chlorophyll Contents ◽  
Complex Processes ◽  
Ppr Protein ◽  
Ppr Proteins ◽  
Mobility Shift Assay

Chloroplast biogenesis and development are highly complex processes requiring interactions between plastids and nuclear genomic products. Pentatricopeptide repeat (PPR) proteins play an essential role in the development of chloroplasts; however, it remains unclear how RNA editing factors influence soybean development. In this study, a Glycine max pale green leaf 2 mutant (Gmpgl2) was identified with decreased chlorophyll contents. Genetic mapping revealed that a single-nucleotide deletion at position 1949 bp in the Glyma.05g132700 gene in the Gmpgl2 mutant, resulting in a truncated GmPGL2 protein. The nuclear-encoded GmPGL2 is a PLS-type PPR protein that localizes to the chloroplasts. The C-to-U editing efficiencies of rps16, rps18, ndhB, ndhD, ndhE, and ndhF were reduced in the Gmpgl2 mutant. RNA electrophoresis mobility shift assay (REMSA) analysis further revealed that GmPGL2 binds to the immediate upstream sequences at RNA editing sites of rps16 and ndhB in vitro, respectively. In addition, GmPGL2 was found to interact with GmMORF8, GmMORF9, and GmORRM6. These results suggest that GmPGL2 participates in C-to-U RNA editing via the formation of a complex RNA editosome in soybean chloroplasts.

scholarly journals A novel E-Subgroup Pentatricopeptide Repeat Protein DEK55 is Responsible for RNA Editing at 15 Sites and Splicing of nad1 and nad4 in Maize

2020 ◽  
Author(s):  
Ru Chang Ren ◽  
Xu Wei Yan ◽  
Ya Jie Zhao ◽  
Yi Ming Wei ◽  
Xiaoduo Lu ◽  
...  
Keyword(s):  
Rna Editing ◽  
Endosperm Development ◽  
Pentatricopeptide Repeat ◽  
Reading Frame ◽  
Maize Kernel ◽  
Ppr Protein ◽  
Ppr Proteins ◽  
Large Protein Family ◽  
Underlying Mechanisms ◽  
Mutant Phenotypes

Abstract Background Pentatricopeptide repeat (PPR) proteins is a large protein family, which participate in RNA processing in organelles and plant growth. Previous reports have generally considered E-subgroup PPR proteins as an editing factors for RNA editing. However, the underlying mechanisms and effects of E-subgroup PPR proteins remain to be investigated.Results In this study, we recognized and identified a new maize kernel mutant with arrested embryo and endosperm development, defective kernel 55 (dek55). Genetic and molecular evidences suggest that the defective kernels resulted from a mononucleotide alteration (C to T) at + 449 in the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within mitochondria. Molecular analyses suggest that DEK55 plays crucial roles in RNA editing at multiple sites of ribosomal protein S13, ATP synthase subunit1, NADH dehydrogenase-6 (nad6), and nad9 transcripts as well as in splicing of nad1 and nad4. The mutation of DEK55 lead to the dysfunction of mitochondrial complex I.Conclusions Our results demonstrate that the DEK55 mutation is responsible for the dek55 mutant phenotypes, as it affects mitochondrial function that is essential for maize kernel development. This study also provides novel insight into the molecular function of E-subgroup PPR proteins in plant organellar RNA metabolism.

scholarly journals The novel E-subgroup pentatricopeptide repeat protein DEK55 is responsible for RNA editing at multiple sites and for the splicing of nad1 and nad4 in maize

2020 ◽  
Author(s):  
Ru Chang Ren ◽  
Xu Wei Yan ◽  
Ya Jie Zhao ◽  
Yi Ming Wei ◽  
Xiaoduo Lu ◽  
...  
Keyword(s):  
Rna Editing ◽  
Rna Processing ◽  
Mitochondrial Gene ◽  
Endosperm Development ◽  
Molecular Evidence ◽  
Pentatricopeptide Repeat ◽  
Reading Frame ◽  
Maize Kernel ◽  
Ppr Protein ◽  
Ppr Proteins

Abstract Background: Pentatricopeptide repeat (PPR) proteins compose a large protein family whose members are involved in both RNA processing in organelles and plant growth. Previous reports have shown that E-subgroup PPR proteins are involved in RNA editing. However, the additional functions and roles of the E-subgroup PPR proteins are unknown. Results: In this study, we developed and identified a new maize kernel mutant with arrested embryo and endosperm development, i.e., defective kernel (dek) 55 (dek55). Genetic and molecular evidence suggested that the defective kernels resulted from a mononucleotide alteration (C to T) at +449 bp within the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within the mitochondria. Molecular analyses showed that the editing percentage of 24 RNA editing sites decreased and that of seven RNA editing sites increased in dek55 kernels, the sites of which were distributed across 14 mitochondrial gene transcripts. Moreover, the splicing efficiency of nad1 introns 1 and 4 and nad4 intron 1 significantly decreased in dek55 compared with the wild type (WT). These results indicate that DEK55 plays a crucial role in RNA editing at multiple sites as well as in the splicing of nad1 and nad4 introns. Mutation in the DEK55 gene led to the dysfunction of mitochondrial complex I. Moreover, yeast two-hybrid assays showed that DEK55 interacts with two multiple organellar RNA-editing factors (MORFs), i.e., ZmMORF1 (Zm00001d049043) and ZmMORF8 (Zm00001d048291).Conclusions: Our results demonstrated that a mutation in the DEK55 gene affects the mitochondrial function essential for maize kernel development. Our results also provide novel insight into the molecular functions of E-subgroup PPR proteins involved in plant organellar RNA processing.

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