A truncated variant of the ribosome-associated trigger factor specifically contributes to plant chloroplast ribosome biogenesis

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Jan. 13, 2025

Molecular chaperones are essential throughout a protein's life and act already during protein synthesis. Bacteria chloroplasts of plant cells share the ribosome-associated chaperone trigger factor (Tig1 in plastids), facilitating maturation emerging nascent polypeptides. While typical employ three domains for their task, here described truncated form, Tig2, contains just ribosome binding domain. Tig2 is widely present green plants appears to have acquired an entirely different task than co-translational polypeptide folding. deletion results remarkable leaf developmental defects cold-exposed Arabidopsis thaliana specific plastidic ribosomes. Our data indicate that functions biogenesis by promoting large subunit. We hypothesize ribosomal tunnel-exit surface aids protecting this sensitive assembly. illustrates fascinating concept how domain evolved individually, serving completely molecular task.

Language: Английский

---

Defective Processing of Cytoplasmic and Chloroplast Ribosomal RNA in the Absence of Arabidopsis DXO1

Plant Cell & Environment, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

Decapping 5'-3' exoribonucleases from the DXO/Rai1 family are highly conserved among eukaryotes and exhibit diverse enzymatic activities depending on organism. The biochemical structural properties of plant DXO1 differ yeast animal counterparts, which is reflected in vivo functions this enzyme. Here we show that Arabidopsis contributes to efficient processing rRNA precursors both nucleolar/cytosolic chloroplast maturation pathways. However, defects DXO1-deficient plants do not depend catalytic activity enzyme but rely its plant-specific N-terminal extension, responsible for interaction with mRNA cap methyltransferase RNMT1. Our RNA sequencing analyses dxo1 mutation deregulates expression many ribosomal protein genes, most likely leading inefficient or delayed pre-rRNA maturation. These phenotypes partially suppressed by RNMT1 overexpression, suggesting defective synthesis may be responsible, at least some extent, observed effects.

Language: Английский

---

A PPR Protein RFCD1 Affects Chloroplast Gene Expression and Chloroplast Development in Arabidopsis

Plants, Journal Year: 2025, Volume and Issue: 14(6), P. 921 - 921

Published: March 15, 2025

Chloroplast development is a highly complex process, involving many regulatory mechanisms that remain poorly understood. This study reports novel PPR protein, RFCD1 (Regulation Factor of Development 1). Fluorescence localization analysis reveals the N-terminal 60 amino acids fused with GFP protein specifically direct to chloroplast. The knockout mutant embryo-lethal. RNA interference (RNAi) transgenic lines display chlorosis phenotypes and abnormal chloroplast development. Quantitative real-time PCR (qRT-PCR) showed expression levels plastid-encoded polymerase (PEP) genes were significantly decreased in RNAi lines. Furthermore, blotting results RNA-seq data processing plastid rRNA was also affected Taken together, these indicate might be involved gene processing, which essential for Arabidopsis.

Language: Английский

---

The major nucleoid-associated protein WHIRLY1 promotes chloroplast development in barley

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 7, 2024

ABSTRACT WHIRLY1 is a DNA-binding protein of high abundance in chloroplast nucleoids, which have complex proteome consisting proteins involved gene expression and unexpected indicating links to energy production biosynthetic activities chloroplasts. In addition, has second localization the nucleus making it an excellent candidate for chloroplast-to-nucleus communication. To unravel role structure composition nucleoids its potential involvement retrograde signaling during development, knockout mutants HvWHIRLY1 were prepared by site-directed mutagenesis using Cas9 endonuclease. contrast rice maize, die after seedling stage, barley why1 survive produce grains. Leaves are initially pale get green with time ( xantha-to-green phenotype). However, chlorophyll content primary leaves stayed distinctly lower than that wild-type leaves, coinciding rather heterogeneous plastid population, whereby only 50% developed normal thylakoid membrane system. For comparison, mature foliage had almost levels but severely reduced photosynthetic capacity. A analysis chloroplasts isolated from revealed absence WHIRLY1, abundances considerable fraction downregulated. The included multiple nucleoid-associated including components transcriptional apparatus. Furthermore, ribosomal proteins, subunits pyruvate dehydrogenase, CLP protease, ATP synthase, Rubisco chaperons/chaperonins found be conclusion, characterization mutant plants not essential development. Rather, ensures fast failure-free progression development remodeling serve as assembly platforms concerted workflow numerous processes required Gene analyses disturbance signaled nucleus, part biogenic plastids.

Language: Английский

---

Multilayered Regulation of Plastids and Mitochondria

Plant and Cell Physiology, Journal Year: 2024, Volume and Issue: 65(4), P. 473 - 476

Published: April 1, 2024

Plastids and mitochondria, the powerhouses of plant cells, have long intrigued scientists due to their crucial role in supporting complex life on Earth.Despite importance, these organelles are still regarded as hidden gems box, they both difficult analyze manipulate.While genomes were fully sequenced much earlier than

Language: Английский

---

Unveiling the Role of SlRNC1 in Chloroplast Development and Global Gene Regulation in Tomato Plants

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(13), P. 6898 - 6898

Published: June 24, 2024

RNC1, a plant-specific gene, is known for its involvement in splicing group II introns within maize chloroplast. However, role chloroplast development and global gene expression remains poorly understood. This study aimed to investigate the of RNC1 identify genes that mediate function entire tomato plants. Consistent with findings maize, silencing induced dwarfism leaf whitening Subcellular localization analysis revealed protein localized both nucleus cytoplasm, including stress granule chloroplasts. Electron microscopic examination transverse sections exposed significant disruptions spatial arrangement thylakoid network upon silencing, crucial efficient light energy capture conversion into chemical energy. Transcriptome suggested potentially impacts plant through associated all three categories (biological processes, cellular components, molecular functions). Overall, our contribute better understanding critical significance physiology.

Language: Английский

---

Dominant‐negative chaperonin mutation ptCPN60α1^S57F uncovers redundancy in chloroplast rRNA processing

The Plant Journal, Journal Year: 2024, Volume and Issue: 119(6), P. 2937 - 2950

Published: Aug. 8, 2024

SUMMARY The biogenesis of functional forms chloroplast ribosomal RNAs (rRNAs) is crucial for the translation mRNAs into polypeptides. However, molecular mechanisms underlying proper processing and maturation rRNA species are poorly understood. Through a genetic approach, we isolated characterized an Arabidopsis mutant, α1‐4 , harboring missense mutation in plastid chaperonin‐60α1 gene. Using allelism tests transgenic manipulation, determined redundancy among ptCPN60 subunits. ptCPN60α1 S57F caused specific defects formation species, including 23S, 5S, 4.5S rRNAs, but not 16S rRNAs. Allelism suggested that dysfunctional competes with other members family. Indeed, overexpression protein wild‐type plants mimicked phenotypes observed while increasing endogenous transcriptional levels ptCPN60α2 β1 β2 β3 mutant partially mitigated abnormal fragmentation Furthermore, demonstrated between ptCPN60β1 ptCPN60β2 through double‐mutant analysis. Collectively, our data reveal novel physiological role subunits generating large 50S subunit chloroplasts.

Language: Английский

---

Comparison of organelle genomes between endangered mangrove plant Dolichandrone spathacea to terrestrial relative provides insights into its origin and adaptative evolution

Frontiers in Plant Science, Journal Year: 2024, Volume and Issue: 15

Published: Sept. 23, 2024

Dolichandrone spathacea is a mangrove associate with high medicinal and ecological values. However, due to the dual-pressure of climate change human activities, D. has become endangered in China. Moreover, misidentification between its terrestrial relative cauda-felina poses further challenges field protection proper usage . Thus, address these problems, we sequenced assembled mitochondrial (mt) chloroplast (cp) genomes for both Comparative analysis revealed apparently different size scaffold number two mt genomes, but similarity cp genomes. Eight regions sequence divergence were identified which might be used developing candidate DNA markers distinguishing species. The splitting was inferred occur at ~6.8 - 7.7 million years ago (Mya), may driven by environment fluctuations late Miocene. In genome, 12 genes related expression photosynthesis-associated proteins detected signatures positive selection, contribute origin evolutionary adaptation These new findings do not only enrich organelle genomic resources species, also provide important genetic clues improving conservation

Language: Английский

---

Chloroplast Translation Machinery

Nucleic acids and molecular biology, Journal Year: 2024, Volume and Issue: unknown, P. 93 - 132

Published: Jan. 1, 2024

Language: Английский

---