Phenotypic reversion infasmutants ofArabidopsis thalianaby reintroduction ofFASgenes: variable recovery of telomeres with major spatial rearrangements and transcriptional reprogramming of 45S rDNA genes

2016 ◽  
Vol 88 (3) ◽  
pp. 411-424 ◽  
Author(s):  
Veronika Pavlištová ◽  
Martina Dvořáčková ◽  
Michal Jež ◽  
Iva Mozgová ◽  
Petr Mokroš ◽  
...  
Keyword(s):  
45S Rdna ◽  
Rdna Genes ◽  
Transcriptional Reprogramming ◽  
Phenotypic Reversion

scholarly journals Binding of Carbonic Anhydrase IX to 45S rDNA Genes Is Prevented by Exportin-1 in Hypoxic Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Emanuele Sasso ◽  
Monica Vitale ◽  
Francesca Monteleone ◽  
Francesca Ludovica Boffo ◽  
Margherita Santoriello ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Nuclear Export ◽  
Ph Regulation ◽  
Surrogate Marker ◽  
Carbonic Anhydrase Ix ◽  
Gene Promoters ◽  
45S Rdna ◽  
Rdna Genes ◽  
Rdna Gene ◽  
Ca Ix

Carbonic anhydrase IX (CA IX) is a surrogate marker of hypoxia, involved in survival and pH regulation in hypoxic cells. We have recently characterized its interactome, describing a set of proteins interacting with CA IX, mainly in hypoxic cells, including several members of the nucleocytoplasmic shuttling apparatuses. Accordingly, we described complex subcellular localization for this enzyme in human cells, as well as the redistribution of a carbonic anhydrase IX pool to nucleoli during hypoxia. Starting from this evidence, we analyzed the possible contribution of carbonic anhydrase IX to transcription of the 45S rDNA genes, a process occurring in nucleoli. We highlighted the binding of carbonic anhydrase IX to nucleolar chromatin, which is regulated by oxygen levels. In fact, CA IX was found on 45S rDNA gene promoters in normoxic cells and less represented on these sites, in hypoxic cells and in cells subjected to acetazolamide-induced acidosis. Both conditions were associated with increased representation of carbonic anhydrase IX/exportin-1 complexes in nucleoli. 45S rRNA transcript levels were accordingly downrepresented. Inhibition of nuclear export by leptomycin B suggests a model in which exportin-1 acts as a decoy, in hypoxic cells, preventing carbonic anhydrase IX association with 45S rDNA gene promoters.

scholarly journals Sequencing of the Arabidopsis NOR2 reveals its distinct organization and tissue-specific rRNA ribosomal variants

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jason Sims ◽  
Giovanni Sestini ◽  
Christiane Elgert ◽  
Arndt von Haeseler ◽  
Peter Schlögelhofer
Keyword(s):  
Rrna Gene ◽  
Sequence Information ◽  
45S Rdna ◽  
Rdna Genes ◽  
Tissue Specific ◽  
Short Read Sequencing ◽  
Sequencing Technologies ◽  
Nucleolus Organizing Region ◽  
Specific Manner ◽  
Genes Encoding

AbstractDespite vast differences between organisms, some characteristics of their genomes are conserved, such as the nucleolus organizing region (NOR). The NOR is constituted of multiple, highly repetitive rDNA genes, encoding the catalytic ribosomal core RNAs which are transcribed from 45S rDNA units. Their precise sequence information and organization remain uncharacterized. Here, using a combination of long- and short-read sequencing technologies we assemble contigs of the Arabidopsis NOR2 rDNA domain. We identify several expressed rRNA gene variants which are integrated into translating ribosomes in a tissue-specific manner. These findings support the concept of tissue specific ribosome subpopulations that differ in their rRNA composition and provide insights into the higher order organization of NOR2.

Karyotype analysis and physical mapping of the 5S and 45S rDNA genes in Tigridia pavonia var. Dulce (Iridaceae)

Caryologia ◽  
2017 ◽  
Vol 71 (1) ◽  
pp. 1-6
Author(s):  
Hugo Abelardo Arroyo-Martínez ◽  
Amaury Martín Arzate-Fernández ◽  
Rodrigo Barba-González ◽  
José Luis Piña-Escutia
Keyword(s):  
Physical Mapping ◽  
Karyotype Analysis ◽  
45S Rdna ◽  
Rdna Genes ◽  
5S And 45S Rdna

Physical mapping of 5S and 45S rDNA genes and ploidy levels of Iranian Asparagus species

2016 ◽  
Vol 211 ◽  
pp. 269-276 ◽  
Author(s):  
Seyyed Javad Mousavizadeh ◽  
Mohammad Reza Hassandokht ◽  
Abdolkarim Kashi ◽  
Juan Gil ◽  
Adoracion Cabrera ◽  
...  
Keyword(s):  
Physical Mapping ◽  
45S Rdna ◽  
Ploidy Levels ◽  
Rdna Genes ◽  
5S And 45S Rdna

Novel players fine-tune plant trade-offs

2015 ◽  
Vol 58 ◽  
pp. 83-100 ◽  
Author(s):  
Selena Gimenez-Ibanez ◽  
Marta Boter ◽  
Roberto Solano
Keyword(s):  
Ubiquitin Ligase ◽  
Feedback Loop ◽  
Molecular Level ◽  
26S Proteasome ◽  
Signalling Molecules ◽  
Transcriptional Reprogramming ◽  
Trade Offs ◽  
Jaz Proteins ◽  
Regulatory Feedback Loop ◽  
Fine Tune

Jasmonates (JAs) are essential signalling molecules that co-ordinate the plant response to biotic and abiotic challenges, as well as co-ordinating several developmental processes. Huge progress has been made over the last decade in understanding the components and mechanisms that govern JA perception and signalling. The bioactive form of the hormone, (+)-7-iso-jasmonyl-l-isoleucine (JA-Ile), is perceived by the COI1–JAZ co-receptor complex. JASMONATE ZIM DOMAIN (JAZ) proteins also act as direct repressors of transcriptional activators such as MYC2. In the emerging picture of JA-Ile perception and signalling, COI1 operates as an E3 ubiquitin ligase that upon binding of JA-Ile targets JAZ repressors for degradation by the 26S proteasome, thereby derepressing transcription factors such as MYC2, which in turn activate JA-Ile-dependent transcriptional reprogramming. It is noteworthy that MYCs and different spliced variants of the JAZ proteins are involved in a negative regulatory feedback loop, which suggests a model that rapidly turns the transcriptional JA-Ile responses on and off and thereby avoids a detrimental overactivation of the pathway. This chapter highlights the most recent advances in our understanding of JA-Ile signalling, focusing on the latest repertoire of new targets of JAZ proteins to control different sets of JA-Ile-mediated responses, novel mechanisms of negative regulation of JA-Ile signalling, and hormonal cross-talk at the molecular level that ultimately determines plant adaptability and survival.

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