The multiple faces of Set1This paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (4) ◽  
pp. 536-548 ◽  
Author(s):  
Pierre-Marie Dehé ◽  
Vincent Géli
Keyword(s):  
Transcriptional Activation ◽  
Peer Review Process ◽  
Position Effect ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Set Domain ◽  
Terminal Set ◽  
Multiple Phenotypes ◽  
Length Regulation ◽  
Selection Of

In Saccharomyces cerevisiae, H3 methylation at lysine 4 (H3K4) is mediated by Set1. Set1 is a large protein bearing a conserved RNA recognition motif in addition to its catalytic C-terminal SET domain. The SET and RRM domains are conserved in Set1 orthologs from yeast to humans. Set1 belongs to a complex of 8 proteins, also showing a striking conservation, most subunits being required to efficiently catalyze methylation of H3K4. The deletion of SET1 is not lethal but has pleiotropic phenotypes. It affects growth, transcriptional activation, repression and elongation, telomere length regulation, telomeric position effect, rDNA silencing, meiotic differentiation, DNA repair, chromosome segregation, and cell wall organization. In this review, we discuss the regulation of H3K4 methylation and try to link Set1 activity with the multiple phenotypes displayed by cells lacking Set1. We also suggest that Set1 may have multiple targets.

scholarly journals Mutant Alleles of the Drosophila trithorax Gene Produce Common and Unusual Homeotic and Other Developmental Phenotypes

Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 319-344
Author(s):  
Thomas R Breen
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Protein Isoforms ◽  
Homeotic Genes ◽  
Set Domain ◽  
Human Homologue ◽  
Terminal Set ◽  
Hypomorphic Alleles ◽  
Different Levels ◽  
Target Gene Transcription

Abstract trithorax (trx) encodes chromosome-binding proteins required throughout embryogenesis and imaginal development for tissue- and cell-specific levels of transcription of many genes including homeotic genes of the ANT-C and BX-C. trx encodes two protein isoforms that contain conserved motifs including a C-terminal SET domain, central PHD fingers, an N-terminal DNA-binding homology, and two short motifs also found in the TRX human homologue, ALL1. As a first step to characterizing specific developmental functions of TRX, I examined phenotypes of 420 combinations of 21 trx alleles. Among these are 8 hypomorphic alleles that are sufficient for embryogenesis but provide different levels of trx function at homeotic genes in imaginal cells. One allele alters the N terminus of TRX, which severely impairs larval and imaginal growth. Hypomorphic alleles that alter different regions of TRX equivalently reduce function at affected genes, suggesting TRX interacts with common factors at different target genes. All hypomorphic alleles examined complement one another, suggesting cooperative TRX function at target genes. Comparative effects of hypomorphic genotypes support previous findings that TRX has tissue-specific interactions with other factors at each target gene. Some hypomorphic genotypes also produce phenotypes that suggest TRX may be a component of signal transduction pathways that provide tissue- and cell-specific levels of target gene transcription.

scholarly journals Tethering-induced destabilization and ATP-binding for tandem RRM domains of ALS-causing TDP-43 and hnRNPA1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mei Dang ◽  
Yifan Li ◽  
Jianxing Song
Keyword(s):  
Conformational Dynamics ◽  
Md Simulations ◽  
Atp Binding ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Nucleic Acid Binding ◽  
General Role ◽  
Nmr Characterization ◽  
Lateral Sclerosis

AbstractTDP-43 and hnRNPA1 contain tandemly-tethered RNA-recognition-motif (RRM) domains, which not only functionally bind an array of nucleic acids, but also participate in aggregation/fibrillation, a pathological hallmark of various human diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), alzheimer's disease (AD) and Multisystem proteinopathy (MSP). Here, by DSF, NMR and MD simulations we systematically characterized stability, ATP-binding and conformational dynamics of TDP-43 and hnRNPA1 RRM domains in both tethered and isolated forms. The results reveal three key findings: (1) upon tethering TDP-43 RRM domains become dramatically coupled and destabilized with Tm reduced to only 49 °C. (2) ATP specifically binds TDP-43 and hnRNPA1 RRM domains, in which ATP occupies the similar pockets within the conserved nucleic-acid-binding surfaces, with the affinity slightly higher to the tethered than isolated forms. (3) MD simulations indicate that the tethered RRM domains of TDP-43 and hnRNPA1 have higher conformational dynamics than the isolated forms. Two RRM domains become coupled as shown by NMR characterization and analysis of inter-domain correlation motions. The study explains the long-standing puzzle that the tethered TDP-43 RRM1–RRM2 is particularly prone to aggregation/fibrillation, and underscores the general role of ATP in inhibiting aggregation/fibrillation of RRM-containing proteins. The results also rationalize the observation that the risk of aggregation-causing diseases increases with aging.

scholarly journals Affinity and Structural Analysis of the U1A RNA Recognition Motif with Engineered Methionines to Improve Experimental Phasing

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 273
Author(s):  
Yoshita Srivastava ◽  
Rachel Bonn-Breach ◽  
Sai Shashank Chavali ◽  
Geoffrey M. Lippa ◽  
Jermaine L. Jenkins ◽  
...  
Keyword(s):  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Molecular Replacement ◽  
Hydrophobic Core ◽  
Anomalous Diffraction ◽  
Recognition Motif ◽  
Determination Process ◽  
Experimental Phasing ◽  
Crystal Contacts ◽  
Apical Loop

RNA plays a central role in all organisms and can fold into complex structures to orchestrate function. Visualization of such structures often requires crystallization, which can be a bottleneck in the structure-determination process. To promote crystallization, an RNA-recognition motif (RRM) of the U1A spliceosomal protein has been co-opted as a crystallization module. Specifically, the U1-snRNA hairpin II (hpII) single-stranded loop recognized by U1A can be transplanted into an RNA target to promote crystal contacts and to attain phase information via molecular replacement or anomalous diffraction methods using selenomethionine. Herein, we produced the F37M/F77M mutant of U1A to augment the phasing capability of this powerful crystallization module. Selenomethionine-substituted U1A(F37M/F77M) retains high affinity for hpII (KD of 59.7 ± 11.4 nM). The 2.20 Å resolution crystal structure reveals that the mutated sidechains make new S-π interactions in the hydrophobic core and are useful for single-wavelength anomalous diffraction. Crystals were also attained of U1A(F37M/F77M) in complex with a bacterial preQ1-II riboswitch. The F34M/F37M/F77M mutant was introduced similarly into a lab-evolved U1A variant (TBP6.9) that recognizes the internal bulged loop of HIV-1 TAR RNA. We envision that this short RNA sequence can be placed into non-essential duplex regions to promote crystallization and phasing of target RNAs. We show that selenomethionine-substituted TBP6.9(F34M/F37M/F77M) binds a TAR variant wherein the apical loop was replaced with a GNRA tetraloop (KD of 69.8 ± 2.9 nM), laying the groundwork for use of TBP6.9(F34M/F37M/F77M) as a crystallization module. These new tools are available to the research community.

Identification and expression analysis of Dazl homologue in Cynops cyanurus

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Yinjiao Zhao ◽  
Ya Du ◽  
Qinglan Ge ◽  
Fang Yan ◽  
Shu Wei
Keyword(s):  
Phylogenetic Analysis ◽  
Comparative Studies ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Specific Expression ◽  
Recognition Motif ◽  
Deleted In Azoospermia ◽  
Specific Expression Pattern

Summary The Dazl (deleted in azoospermia-like) gene encodes an RNA-binding protein containing an RNA recognition motif (RRM) and a DAZ motif. Dazl is essential for gametogenesis in vertebrates. In this study, we report the cloning of Dazl cDNA from Cynops cyanurus. Ccdazl mRNA showed a germline-specific expression pattern as expected. Ccdazl expression gradually decreased during oogenesis, suggesting that it may be involved in oocyte development. Phylogenetic analysis revealed that the Ccdazl protein shares conserved motifs/domains with Dazl proteins from other species. Cloning of Ccdazl provides a new tool to carry out comparative studies of germ cell development in amphibians.

scholarly journals RNA recognition and self-association of CPEB4 is mediated by its tandem RRM domains

2014 ◽  
Vol 42 (15) ◽  
pp. 10185-10195 ◽  
Author(s):  
Constanze Schelhorn ◽  
James M.B. Gordon ◽  
Lidia Ruiz ◽  
Javier Alguacil ◽  
Enrique Pedroso ◽  
...  
Keyword(s):  
Rna Binding ◽  
Titration Calorimetry ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Mobility Shift ◽  
Cytoplasmic Polyadenylation ◽  
C Terminus ◽  
Self Association ◽  
Mobility Shift Assay ◽  
A Minor

Abstract Cytoplasmic polyadenylation is regulated by the interaction of the cytoplasmic polyadenylation element binding proteins (CPEB) with cytoplasmic polyadenylation element (CPE) containing mRNAs. The CPEB family comprises four paralogs, CPEB1–4, each composed of a variable N-terminal region, two RNA recognition motif (RRM) and a C-terminal ZZ-domain. We have characterized the RRM domains of CPEB4 and their binding properties using a combination of biochemical, biophysical and NMR techniques. Isothermal titration calorimetry, NMR and electrophoretic mobility shift assay experiments demonstrate that both the RRM domains are required for an optimal CPE interaction and the presence of either one or two adenosines in the two most commonly used consensus CPE motifs has little effect on the affinity of the interaction. Both the single RRM1 and the tandem RRM1–RRM2 have the ability to dimerize, although representing a minor population. Self-association does not affect the proteins’ ability to interact with RNA as demonstrated by ion mobility–mass spectrometry. Chemical shift effects measured by NMR of the apo forms of the RRM1–RRM2 samples indicate that the two domains are orientated toward each other. NMR titration experiments show that residues on the β-sheet surface on RRM1 and at the C-terminus of RRM2 are affected upon RNA binding. We propose a model of the CPEB4 RRM1–RRM2–CPE complex that illustrates the experimental data.

scholarly journals Sir Proteins, Rif Proteins, and Cdc13p BindSaccharomyces Telomeres In Vivo

1998 ◽  
Vol 18 (9) ◽  
pp. 5600-5608 ◽  
Author(s):  
Brenda D. Bourns ◽  
Mary Kate Alexander ◽  
Andrew M. Smith ◽  
Virginia A. Zakian
Keyword(s):  
Reporter Gene ◽  
Transcriptional Activation ◽  
Binding Proteins ◽  
Position Effect ◽  
Initiation Site ◽  
Telomeric Sequence ◽  
Transcriptional Activation Domain ◽  
Amino Terminal ◽  
Sir Proteins

ABSTRACT Although a surprisingly large number of genes affect yeast telomeres, in most cases it is not known if their products act directly or indirectly. We describe a one-hybrid assay for telomere binding proteins and use it to establish that six proteins that affect telomere structure or function but which had not been shown previously to bind telomeres in vivo are indeed telomere binding proteins. A promoter-defective allele of HIS3 was placed adjacent to a chromosomal telomere. Candidate proteins fused to a transcriptional activation domain were tested for the ability to activate transcription of the telomere-linked HIS3 gene. Using this system, Rif1p, Rif2p, Sir2p, Sir3p, Sir4p, and Cdc13p were found to be in vivo telomere binding proteins. None of the proteins activated the same reporter gene when it was at an internal site on the chromosome. Moreover, Cdc13p did not activate the reporter gene when it was adjacent to an internal tract of telomeric sequence, indicating that Cdc13p binding was telomere limited in vivo. The amino-terminal 20% of Cdc13p was sufficient to target Cdc13p to a telomere, suggesting that its DNA binding domain was within this portion of the protein. Rap1p, Rif1p, Rif2p, Sir4p, and Cdc13p activated the telomeric reporter gene in a strain lacking Sir3p, which is essential for telomere position effect (TPE). Thus, the telomeric association of these proteins did not require any of the chromatin features necessary for TPE. The data support models in which the telomere acts as an initiation site for TPE by recruiting silencing proteins to the chromosome end.

The nucleosome: a little variation goes a long wayThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (4) ◽  
pp. 505-507 ◽  
Author(s):  
Emily Bernstein ◽  
Sandra B. Hake
Keyword(s):  
Peer Review Process ◽  
Gene Activation ◽  
Epigenetic Inheritance ◽  
Histone Variants ◽  
Post Translational Modifications ◽  
Chromatin Compaction ◽  
Cellular Processes ◽  
Chromatin Template ◽  
Mitosis And Meiosis ◽  
Selection Of

Changes in the overall structure of chromatin are essential for the proper regulation of cellular processes, including gene activation and silencing, DNA repair, chromosome segregation during mitosis and meiosis, X chromosome inactivation in female mammals, and chromatin compaction during apoptosis. Such alterations of the chromatin template occur through at least 3 interrelated mechanisms: post-translational modifications of histones, ATP-dependent chromatin remodeling, and the incorporation (or replacement) of specialized histone variants into chromatin. Of these mechanisms, the exchange of variants into and out of chromatin is the least well understood. However, the exchange of conventional histones for variant histones has distinct and profound consequences within the cell. This review focuses on the growing number of mammalian histone variants, their particular biological functions and unique features, and how they may affect the structure of the nucleosome. We propose that a given nucleosome might not consist of heterotypic variants, but rather, that only specific histone variants come together to form a homotypic nucleosome, a hypothesis that we refer to as the nucleosome code. Such nucleosomes might in turn participate in marking specific chromatin domains that may contribute to epigenetic inheritance.

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