scholarly journals Albino seedling lethality 4; Chloroplast 30S Ribosomal Protein S1 is Required for Chloroplast Ribosome Biogenesis and Early Chloroplast Development in Rice

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kunneng Zhou ◽  
Caijuan Zhang ◽  
Jiafa Xia ◽  
Peng Yun ◽  
Yuanlei Wang ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Chloroplast Development ◽  
Phage Type ◽  
Chloroplast Biogenesis ◽  
Ribosomal Protein S1 ◽  
Seedling Lethality

Abstract Background Ribosomes responsible for transcription and translation of plastid-encoded proteins in chloroplasts are essential for chloroplast development and plant growth. Although most ribosomal proteins in plastids have been identified, the molecular mechanisms regulating chloroplast biogenesis remain to be investigated. Results Here, we identified albinic seedling mutant albino seedling lethality 4 (asl4) caused by disruption of 30S ribosomal protein S1 that is targeted to the chloroplast. The mutant was defective in early chloroplast development and chlorophyll (Chl) biosynthesis. A 2855-bp deletion in the ASL4 allele was verified as responsible for the mutant phenotype by complementation tests. Expression analysis revealed that the ASL4 allele was highly expressed in leaf 4 sections and newly expanded leaves during early leaf development. Expression levels were increased by exposure to light following darkness. Some genes involved in chloroplast biogenesis were up-regulated and others down-regulated in asl4 mutant tissues compared to wild type. Plastid-encoded plastid RNA polymerase (PEP)-dependent photosynthesis genes and nuclear-encoded phage-type RNA polymerase (NEP)-dependent housekeeping genes were separately down-regulated and up-regulated, suggesting that plastid transcription was impaired in the mutant. Transcriptome and western blot analyses showed that levels of most plastid-encoded genes and proteins were reduced in the mutant. The decreased contents of chloroplast rRNAs and ribosomal proteins indicated that chloroplast ribosome biogenesis was impaired in the asl4 mutant. Conclusions Rice ASL4 encodes 30S ribosomal protein S1, which is targeted to the chloroplast. ASL4 is essential for chloroplast ribosome biogenesis and early chloroplast development. These data will facilitate efforts to further elucidate the molecular mechanism of chloroplast biogenesis.

Albino seedling lethality 4 ; chloroplast 30S ribosomal protein S1 required for chloroplast ribosome biogenesis and early chloroplast development in rice

2021 ◽  
Author(s):  
Kunneng Zhou ◽  
Caijuan Zhang ◽  
Jiafa Xia ◽  
Peng Yun ◽  
Yuanlei Wang ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Chloroplast Development ◽  
Chlorophyll Biosynthesis ◽  
Housekeeping Genes ◽  
Chloroplast Biogenesis ◽  
Ribosomal Protein S1 ◽  
Photosynthesis Genes

Abstract Background : Ribosomes responsible for transcription and translation of plastid-encoded proteins in chloroplasts are essential for chloroplast development and plant growth. Although most ribosomal proteins in plastids have been identified, the molecular mechanisms regulating chloroplast biogenesis remain to be investigated. Results: Here, we identified albinic seedling mutant asl4 caused by disruption of 30S ribosomal protein S1 that is targeted to the chloroplast . The mutant was defective in early chloroplast development and chlorophyll biosynthesis . A 2,855-bp deletion in the ASL4 allele was verified as responsible for the mutant phenotype by complementation tests. Expression analysis revealed that the ASL4 allele was highly expressed in leaf 4 sections and newly expanded leaves during early leaf development. Expression levels were increased by exposure to light following darkness. Some genes involved in chloroplast biogenesis were up-regulated and others down-regulated in asl4 mutant tissues compared to wild type. PEP-dependent photosynthesis genes and NEP-dependent housekeeping genes were separately down-regulated and up-regulated, suggesting that plastid transcription was impaired in the mutant. Transcriptome and western blot analyses showed that levels of most plastid-encoded genes and proteins were reduced in the mutant. The decreased contents of chloroplast rRNAs and ribosomal proteins indicated that chloroplast ribosome biogenesis was impaired in the asl4 mutant. Conclusion: Rice ASL4 encodes 30S ribosomal protein S1, which is targeted to the chloroplast. ASL4 is essential for chloroplast ribosome biogenesis and early chloroplast development. These data will facilitate efforts to further elucidate the molecular mechanism of chloroplast biogenesis.

Control points in eucaryotic ribosome biogenesis

1991 ◽  
Vol 69 (1) ◽  
pp. 5-22 ◽  
Author(s):  
D. E. Larson ◽  
P. Zahradka ◽  
B. H. Sells
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Rna Polymerase Iii ◽  
Ribosomal Subunits ◽  
Rrna Species ◽  
Polymerase I ◽  
Ribosomal Precursor ◽  
Precursor Molecules

Ribosome biogenesis in eucaryotic cells involves the coordinated synthesis of four rRNA species, transcribed by RNA polymerase I (18S, 28S, 5.8S) and RNA polymerase III (5S), and approximately 80 ribosomal proteins translated from mRNAs synthesized by RNA polymerase II. Assembly of the ribosomal subunits in the nucleolus, the site of 45S rRNA precursor gene transcription, requires the movement of 5S rRNA and ribosomal proteins from the nucleoplasm and cytoplasm, respectively, to this structure. To integrate these events and ensure the balanced production of individual ribosomal components, different strategies have been developed by eucaryotic organisms in response to a variety of physiological changes. This review presents an overview of the mechanisms modulating the production of ribosomal precursor molecules and the rate of ribosome biogenesis in various biological systems.Key words: rRNA, ribosomal proteins, nucleolus, ribosome.

The relationship between the spoT gene, the synthesis of stable RNA, ribosomal proteins, and the ββ′ subunits of RNA polymerase following a nutritional shiftup of Escherichia coli

1978 ◽  
Vol 56 (6) ◽  
pp. 528-533 ◽  
Author(s):  
Stephen M. Boyle ◽  
Frederick Chu ◽  
Nathan Brot ◽  
Bruce H. Sells
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Rna Synthesis ◽  
Transient Increase ◽  
Spot Gene ◽  
The Relationship

The level of ppGpp and rates of synthesis of stable RNA, ribosomal protein, and the β and β′ subunits of RNA polymerase were measured following a nutritional shiftup in Escherichia coli strains, NF 929 (spoT+) and NF 930 (spoT'−). In the spoT+ strain, ppGpp levels decreased 50% within 2 min following shiftup, and the rates of synthesis of stable RNA, ribosomal proteins, and the β and β′ subunits of RNA polymerase increased with little or no lag. In contrast, in the spoT− strain, ppGpp levels transiently increased 40% during the first 6 min following shiftup. An inhibition in the rate of stable RNA synthesis and a delay in the increased synthesis of ribosomal proteins and β and β′ subunits occurred concurrently with the transient increase in ppGpp. In addition, the DNA-dependent synthesis in vitro of the β and β′ subunits of RNA polymerase was inhibited by physiological levels of ppGpp. Because of the timing and magnitude of the changes in ppGpp levels in the spoT− strain versus the timing when the new rates of stable RNA, ribosomal protein, and β and β′ subunits synthesis are reached, it is concluded that ppGpp is not the sole element regulating the expression of these genes.

scholarly journals Functional domains of the 50S subunit mature late in the assembly process

2013 ◽  
Vol 42 (5) ◽  
pp. 3419-3435 ◽  
Author(s):  
Ahmad Jomaa ◽  
Nikhil Jain ◽  
Joseph H. Davis ◽  
James R. Williamson ◽  
Robert A. Britton ◽  
...  
Keyword(s):  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Functional Sites ◽  
Chemical Probing ◽  
Cryo Electron Microscopy ◽  
Mass Spectrometry Technique ◽  
Spectrometry Technique ◽  
Late Stages ◽  
Trna Binding

Abstract Despite the identification of many factors that facilitate ribosome assembly, the molecular mechanisms by which they drive ribosome biogenesis are poorly understood. Here, we analyze the late stages of assembly of the 50S subunit using Bacillus subtilis cells depleted of RbgA, a highly conserved GTPase. We found that RbgA-depleted cells accumulate late assembly intermediates bearing sub-stoichiometric quantities of ribosomal proteins L16, L27, L28, L33a, L35 and L36. Using a novel pulse labeling/quantitative mass spectrometry technique, we show that this particle is physiologically relevant and is capable of maturing into a complete 50S particle. Cryo-electron microscopy and chemical probing revealed that the central protuberance, the GTPase associating region and tRNA-binding sites in this intermediate are unstructured. These findings demonstrate that key functional sites of the 50S subunit remain unstructured until late stages of maturation, preventing the incomplete subunit from prematurely engaging in translation. Finally, structural and biochemical analysis of a ribosome particle depleted of L16 indicate that L16 binding is necessary for the stimulation of RbgA GTPase activity and, in turn, release of this co-factor, and for conversion of the intermediate to a complete 50S subunit.

scholarly journals Oxidative damage-induced hyperactive ribosome biogenesis participates in tumorigenesis of offspring by cross-interacting with the Wnt and TGF-β1 pathways in IVF embryos

2021 ◽  
Author(s):  
Yue Huang ◽  
Zhiling Li ◽  
En Lin ◽  
Pei He ◽  
Gaizhen Ru
Keyword(s):  
Oxidative Damage ◽  
In Vitro Culture ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Tumor Formation ◽  
Vitro Fertilization ◽  
Egcg Treatment ◽  
Tgf Β1

AbstractIn vitro fertilization (IVF) increases the risk of tumorigenesis in offspring. The increased oxidative damage during IVF may be involved in tumor formation. However, the molecular mechanisms underlying this phenomenon remain largely unclear. Using a well-established model of oxidatively damaged IVF mouse embryos, we applied the iTRAQ method to identify proteins differentially expressed between control and oxidatively damaged zygotes and explored the possible tumorigenic mechanisms, especially with regard to the effects of oxidative damage on ribosome biogenesis closely related to tumorigenesis. The iTRAQ results revealed that ribosomal proteins were upregulated by oxidative stress through the Nucleolin/β-Catenin/n-Myc pathway, which stimulated ribosomes to synthesize an abundance of repair proteins to correct the damaged DNA/chromosomes in IVF-derived embryos. However, the increased percentages of γH2AX-positive cells and apoptotic cells in the blastocyst suggested that DNA repair was insufficient, resulting in aberrant ribosome biogenesis. Overexpression of ribosomal proteins, particularly Rpl15, which gradually increased from the 1-cell to 8-cell stages, indicated persistent hyperactivation of ribosome biogenesis, which promoted tumorigenesis in offspring derived from oxidatively damaged IVF embryos by selectively enhancing the translation of β-Catenin and TGF-β1. The antioxidant epigallocatechin-3-gallate (EGCG) was added to the in vitro culture medium to protect embryos from oxidative damage, and the expression of ribosome-/tumor-related proteins returned to normal after EGCG treatment. This study suggests that regulation of ribosome biogenesis by EGCG may be a means of preventing tumor formation in human IVF-derived offspring, providing a scientific basis for optimizing in vitro culture conditions and improving human-assisted reproductive technology.

scholarly journals Human Ribosomal Proteins RPeL27, RPeL43, and RPeL41 Are Upregulated in Nasopharyngeal Carcinoma Cell Lines

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Edmund Ui-Hang Sim ◽  
Stella Li-Li Chan ◽  
Kher-Lee Ng ◽  
Choon-Weng Lee ◽  
Kumaran Narayanan
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Ribosomal Protein ◽  
Cell Lines ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Expression Patterns ◽  
Transcript Level ◽  
Ribosomal Protein Genes ◽  
Significant Differential Expression ◽  
Protein Levels

Apart from their canonical role in ribosome biogenesis, there is increasing evidence of ribosomal protein genes’ involvement in various cancers. A previous study by us revealed significant differential expression of three ribosomal protein genes (RPeL27, RPeL41, and RPeL43) between cell lines derived from tumor and normal nasopharyngeal epithelium. However, the results therein were based on a semiquantitative assay, thus preliminary in nature. Herein, we provide findings of a deeper analysis of these three genes in the context to nasopharyngeal carcinoma (NPC) tumorigenesis. Their expression patterns were analyzed in a more quantitative manner at transcript level. Their protein expression levels were also investigated. We showed results that are contrary to previous report. Rather than downregulation, these genes were significantly overexpressed in NPC cell lines compared to normal control at both transcript and protein levels. Nevertheless, their association with NPC has been established. Immunoprecipitation pulldown assays indicate the plausible interaction of either RPeL27 or RPeL43 with POTEE/TUBA1A and ACTB/ACTBL2 complexes. In addition, RPeL43 is shown to bind with MRAS and EIF2S1 proteins in a NPC cell line (HK1). Our findings support RPeL27, RPeL41, and RPeL43 as potential markers of NPC and provide insights into the interaction targets of RPeL27 and RPeL43 proteins.

scholarly journals A novel stress response pathway regulates rRNA biogenesis

2020 ◽  
Author(s):  
Witold Szaflarski ◽  
Mateusz Sowiński ◽  
Marta Leśniczak ◽  
Sandeep Ojha ◽  
Anaïs Aulas ◽  
...  
Keyword(s):  
Stress Response ◽  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Protein Translation ◽  
Rrna Processing ◽  
Stress Response Pathway ◽  
Cellular Translation ◽  
Response To Stress ◽  
Ribosomal Protein Synthesis

ABSTRACTProduction of ribosomes is an energy-intensive process owing to the intricacy of these massive macromolecular machines. Each human ribosome contains 80 ribosomal proteins and four non-coding RNAs. Accurate assembly requires precise regulation of protein and RNA subunits. In response to stress, the integrated stress response (ISR) rapidly inhibits global translation. How rRNA is coordinately regulated with the rapid inhibition of ribosomal protein synthesis is not known. Here we show that stress specifically inhibits the first step of rRNA processing. Unprocessed rRNA is stored within the nucleolus, and, when stress resolves, it re-enters the ribosome biogenesis pathway. Retention of unprocessed rRNA within the nucleolus aids in the maintenance of this organelle. This response is independent of the ISR or inhibition of cellular translation but represents an independent stress-response pathway that we term Ribosome Biogenesis Stress Response (RiBiSR). Failure to coordinately regulate ribosomal protein translation and rRNA production results in nucleolar fragmentation. Our study unveils a novel stress response pathway that aims at conserving energy, preserving the nucleolus, and prevents further stress by regulation of rRNA processing.

scholarly journals Ribosomal Protein L10: From Function to Dysfunction

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2503
Author(s):  
Daniela Pollutri ◽  
Marianna Penzo
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Large Subunit ◽  
Inherited Disease ◽  
The Past ◽  
Important Player ◽  
Pathologic Processes ◽  
Cytoplasmic Ribosomes

Eukaryotic cytoplasmic ribosomes are highly structured macromolecular complexes made up of four different ribosomal RNAs (rRNAs) and 80 ribosomal proteins (RPs), which play a central role in the decoding of genetic code for the synthesis of new proteins. Over the past 25 years, studies on yeast and human models have made it possible to identify RPL10 (ribosomal protein L10 gene), which is a constituent of the large subunit of the ribosome, as an important player in the final stages of ribosome biogenesis and in ribosome function. Here, we reviewed the literature to give an overview of the role of RPL10 in physiologic and pathologic processes, including inherited disease and cancer.

scholarly journals Bi-allelic missense disease-causing variants in RPL3L associate neonatal dilated cardiomyopathy with muscle-specific ribosome biogenesis

2020 ◽  
Vol 139 (11) ◽  
pp. 1443-1454
Author(s):  
Mythily Ganapathi ◽  
Loukas Argyriou ◽  
Francisco Martínez-Azorín ◽  
Susanne Morlot ◽  
Gökhan Yigit ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Ribosomal Protein ◽  
In Silico ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Systolic Function ◽  
Ribosomal Subunit ◽  
Autosomal Recessive Inheritance ◽  
Compound Heterozygous ◽  
Ribosomal Protein L3

Abstract Dilated cardiomyopathy (DCM) belongs to the most frequent forms of cardiomyopathy mainly characterized by cardiac dilatation and reduced systolic function. Although most cases of DCM are classified as sporadic, 20–30% of cases show a heritable pattern. Familial forms of DCM are genetically heterogeneous, and mutations in several genes have been identified that most commonly play a role in cytoskeleton and sarcomere-associated processes. Still, a large number of familial cases remain unsolved. Here, we report five individuals from three independent families who presented with severe dilated cardiomyopathy during the neonatal period. Using whole-exome sequencing (WES), we identified causative, compound heterozygous missense variants in RPL3L (ribosomal protein L3-like) in all the affected individuals. The identified variants co-segregated with the disease in each of the three families and were absent or very rare in the human population, in line with an autosomal recessive inheritance pattern. They are located within the conserved RPL3 domain of the protein and were classified as deleterious by several in silico prediction software applications. RPL3L is one of the four non-canonical riboprotein genes and it encodes the 60S ribosomal protein L3-like protein that is highly expressed only in cardiac and skeletal muscle. Three-dimensional homology modeling and in silico analysis of the affected residues in RPL3L indicate that the identified changes specifically alter the interaction of RPL3L with the RNA components of the 60S ribosomal subunit and thus destabilize its binding to the 60S subunit. In conclusion, we report that bi-allelic pathogenic variants in RPL3L are causative of an early-onset, severe neonatal form of dilated cardiomyopathy, and we show for the first time that cytoplasmic ribosomal proteins are involved in the pathogenesis of non-syndromic cardiomyopathies.

scholarly journals Ribosomal Protein L12 Uses a Distinct Nuclear Import Pathway Mediated by Importin 11

2002 ◽  
Vol 22 (4) ◽  
pp. 1266-1275 ◽  
Author(s):  
Scott M. Plafker ◽  
Ian G. Macara
Keyword(s):  
Ribosomal Protein ◽  
Nuclear Import ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Protein Import ◽  
Nuclear Translocation ◽  
Nuclear Accumulation ◽  
Transient Transfection Assay

ABSTRACT Ribosome biogenesis requires the nuclear translocation of ribosomal proteins from their site of synthesis in the cytoplasm to the nucleus. Analyses of the import mechanisms have revealed that most ribosomal proteins can be delivered to the nucleus by multiple transport receptors (karyopherins or importins). We now provide evidence that ribosomal protein L12 (rpL12) is distinguished from the bulk of ribosomal proteins because it accesses the importin 11 pathway as a major route into the nucleus. rpL12 specifically and directly interacted with importin 11 in vitro and in vivo. Both rpL12 binding to and import by importin 11 were inhibited by another importin 11 substrate, UbcM2, indicating that these two cargoes may bind overlapping sites on the transport receptor. In contrast, the import of rpL23a, a ribosomal protein that uses the general ribosomal protein import system, was not competed by UbcM2, and in an in vitro binding assay, importin 11 did not bind to the nuclear localization signal of rpL23a. Furthermore, in a transient transfection assay, the nuclear accumulation of rpL12 was increased by coexpressed importin 11, but not by other importins. These data are consistent with importin 11 being a mediator of rpL12 nuclear import. Taken together, these results indicate that rpL12 uses a distinct nuclear import pathway that may contribute to a mechanism for regulating ribosome synthesis and/or maturation.

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