Characterization of a crucifer plant pre-rRNA processing complex.

  title={Characterization of a crucifer plant pre-rRNA processing complex.},
  author={Julio S{\'a}ez-V{\'a}squez and David Caparros-Ruiz and Fredy Barneche and Manuel Echeverria},
  journal={Biochemical Society transactions},
  volume={32 Pt 4},
In cruciferous plants, the primary pre-rRNA cleavage site (P site) is immediately downstream of four similar, highly conserved sequences (A(1), A(2), A(3) and B) located within the 5'-ETS (5'-external transcribed spacer). In the present study, we describe the characterization of a plant NF D (nuclear factor D) that binds and interacts specifically with this A(123)BP cluster in the rDNA sequence. NF D is a high-molecular-mass complex containing nucleolin, fibrillarin and U3 and U14 snoRNAs… 

Arabidopsis small nucleolar RNA monitors the efficient pre-rRNA processing during ribosome biogenesis

This study shows that an uncharacterized C/D box snoRNA, HIDDEN TREASURE 2 (HID2), functions as a prominent player in the monitoring of efficient pre-rRNA processing, which, in turn, is essential for accurate ribosome assembly in Arabidopsis.

Identification of protein factors and U3 snoRNAs from a Brassica oleracea RNP complex involved in the processing of pre-rRNA.

It is concluded that the BoU3 snoRNP complex is mainly required for 40S pre-ribosome synthesis and it is also expected that U3snoRNA variants and interacting proteins might play a major role in BoU 3 sno RNP complex assembly and/or function.

Ribosomal RNA Biogenesis and Its Response to Chilling Stress in Oryza sativa1[OPEN]

Overall, this study identified the pre-rRNA processing pathway in rice and showed that ribosome biogenesis is quickly inhibited by low temperatures, which may shed light on the link between ribosomes biogenesis and environmental acclimation in crop plants.

Nucleolar Proteome Analysis and Proteasomal Activity Assays Reveal a Link between Nucleolus and 26S Proteasome in A. thaliana

A novel mass spectrometry analysis of isolated nucleoli from Arabidopsis thaliana plants using the FANoS (Fluorescence Assortment Nucleolus Sorting) strategy identifies many ribosome biogenesis factors and proteins non-related with ribosomes biogenesis in agreement with the recognized multi-functionality of the nucleolus.

Variations in a team: Major and minor variants of Arabidopsis thaliana rDNA genes

A model is presented to explain how transcription of this this unusual variant, maintained in an active state by nucleolin binding, could be involved in control of expression of the major variant, while absence of nucleolin leads to silencing of the minor variant and consequent expression ofThe major variant.

Ribosome Biogenesis in Plants: From Functional 45S Ribosomal DNA Organization to Ribosome Assembly Factors[OPEN]

The functional organization of ribosomal DNA and ribosome assembly in plants is described, along with recent findings concerning a plant-specific mechanism involved in ribosome stress responses. The



A U3 small nuclear ribonucleoprotein-requiring processing event in the 5' external transcribed spacer of Xenopus precursor rRNA

A processing site has been identified within the 5' external transcribed spacer of Xenopus laevis and X. borealis pre-RNAs, and in vivo processing can be reproduced in vitro, suggesting that this 5' ETS processing site serves an evolutionarily selective function.

Nucleolin functions in the first step of ribosomal RNA processing

It is shown that nucleolin, one of the major RNA‐binding proteins of the nucleolus, is involved in the early cleavage of pre‐rRNA, and it is demonstrated that this interaction is required for the processing reaction in vitro.

A large nucleolar U3 ribonucleoprotein required for 18S ribosomal RNA biogenesis

A large ribonucleoprotein (RNP) complex from Saccharomyces cerevisiae that contains the U3 snoRNA and 28 proteins is purified and it is suggested that this complex may correspond to the terminal knobs present at the 5′ ends of nascent pre-rRNAs.

Two ribosomal DNA-binding factors interact with a cluster of motifs on the 5' external transcribed spacer, upstream from the primary pre-rRNA processing site in a higher plant.

It is shown that NF D binds specifically to the A123 clustered motifs but not to similar B or P motifs, which indicates that these factors regulate rDNA transcription elongation at the level of the primary pre-rRNA processing site in crucifers.

Nucleolin: a multifunctional major nucleolar phosphoprotein.

This multifunctional protein has been implicated to be involved directly or indirectly in many metabolic processes such as ribosome biogenesis, cytokinesis, nucleogenesis, cell proliferation and growth, cytoplasmic-nucleolar transport of ribosomal components, transcriptional repression, replication, signal transduction, inducing chromatin decondensation and many more (see text).

Extensive purification of a putative RNA polymerase I holoenzyme from plants that accurately initiates rRNA gene transcription in vitro.

A cell-free system from broccoli inflorescence that supports promoter-dependent RNA pol I transcription in vitro is reported that suggests the occurrence of a holoenzyme complex is probably not unique to the pol II system but may be a general feature of eukaryotic nuclear polymerases.

Base pairing between U3 and the pre‐ribosomal RNA is required for 18S rRNA synthesis.

The nucleolus, the site of pre‐ribosomal RNA (pre‐rRNA) synthesis and processing in eukaryotic cells, contains a number of small nucleolar RNAs (snoRNAs) which require direct base pairing between snoRNA and the substrate.

Repression of RNA Polymerase I Transcription by Nucleolin Is Independent of the RNA Sequence That Is Transcribed*

It is proposed that nucleolin affects RNA pol I transcription by acting directly on the transcription machinery or on the rDNA promoter sequences and not, as previously thought, through interaction with the nascent pre-rRNA.

Interaction of nucleolar phosphoprotein C23 with cloned segments of rat ribosomal deoxyribonucleic acid.

Results suggest that protein C23 has a preference for binding DNA sequences in the nontranscribed spacer of rDNA.

The terminal balls characteristic of eukaryotic rRNA transcription units in chromatin spreads are rRNA processing complexes.

It is shown that a rRNA-processing signal in the 5'-external transcribed spacer (ETS) of the Xenopus laevis ribosomal primary transcript forms a large, processing-related complex with factors of the xenopus oocyte, analogous to 5' ETS processing complexes found in other vertebrate cell types.