scholarly journals Analysis of protein domains and Rett syndrome mutations indicate that multiple regions influence chromatin-binding dynamics of the chromatin-associated protein MECP2 in vivo

2008 ◽  
Vol 121 (7) ◽  
pp. 1128-1137 ◽  
Author(s):  
A. Kumar ◽  
S. Kamboj ◽  
B. M. Malone ◽  
S. Kudo ◽  
J. L. Twiss ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Protein Domains ◽  
Chromatin Binding ◽  
Multiple Regions ◽  
Protein Mecp2

scholarly journals The Trithorax group protein ASH1 requires a combination of BAH domain and AT hooks, but not the SET domain, for mitotic chromatin binding and survival

Chromosoma ◽  
2021 ◽  
Author(s):  
Philipp A. Steffen ◽  
Christina Altmutter ◽  
Eva Dworschak ◽  
Sini Junttila ◽  
Attila Gyenesei ◽  
...  
Keyword(s):  
Transcriptional Profiling ◽  
Histone H3 ◽  
Chromatin Binding ◽  
Set Domain ◽  
Trithorax Group ◽  
Trxg Protein ◽  
Group Protein ◽  
Bah Domain ◽  
Mitotic Chromatin

AbstractThe Drosophila Trithorax group (TrxG) protein ASH1 remains associated with mitotic chromatin through mechanisms that are poorly understood. ASH1 dimethylates histone H3 at lysine 36 via its SET domain. Here, we identify domains of the TrxG protein ASH1 that are required for mitotic chromatin attachment in living Drosophila. Quantitative live imaging demonstrates that ASH1 requires AT hooks and the BAH domain but not the SET domain for full chromatin binding in metaphase, and that none of these domains are essential for interphase binding. Genetic experiments show that disruptions of the AT hooks and the BAH domain together, but not deletion of the SET domain alone, are lethal. Transcriptional profiling demonstrates that intact ASH1 AT hooks and the BAH domain are required to maintain expression levels of a specific set of genes, including several involved in cell identity and survival. This study identifies in vivo roles for specific ASH1 domains in mitotic binding, gene regulation, and survival that are distinct from its functions as a histone methyltransferase.

scholarly journals In vivo Polycomb kinetics and mitotic chromatin binding distinguish stem cells from differentiated cells

2012 ◽  
Vol 26 (8) ◽  
pp. 857-871 ◽  
Author(s):  
J. P. Fonseca ◽  
P. A. Steffen ◽  
S. Muller ◽  
J. Lu ◽  
A. Sawicka ◽  
...  
Keyword(s):  
Stem Cells ◽  
Chromatin Binding ◽  
Differentiated Cells ◽  
Mitotic Chromatin

A Chemometric Analysis for Evaluation of Early-Stage Cartilage Degradation by Infrared Fiber-Optic Probe Spectroscopy

2005 ◽  
Vol 59 (12) ◽  
pp. 1527-1533 ◽  
Author(s):  
Guiyang Li ◽  
Mary Thomson ◽  
Edward Dicarlo ◽  
Xu Yang ◽  
Bryan Nestor ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Early Stage ◽  
Cartilage Degradation ◽  
Fiber Optic Probe ◽  
Replacement Surgery ◽  
Multiple Regions ◽  
Grading Scale ◽  
Optic Probe ◽  
Probe Spectroscopy

In vivo identification of early-stage cartilage degradation could positively impact disease progression in osteoarthritis, but to date remains a challenge. The primary goal of this study was to develop an infrared fiber-optic probe (IFOP) chemometric method using partial least squares (PLS1) to objectively determine the degree of cartilage degradation. Arthritic human tibial plateaus ( N = 61) were obtained during knee replacement surgery and analyzed by IFOP. IFOP data were collected from multiple regions of each specimen and the cartilage graded according to the Collins Visual Grading Scale of 0, 1, 2, or 3. These grades correspond to cartilage morphology that displayed normal, swelling or softening, superficially slight fibrillation, and deeper fibrillation or serious fibrillation, respectively. The model focused on detecting early cartilage degradation and therefore utilized data from grades 0, 1, and 2. The best PLS1 calibration utilized the spectral range 1733–984 cm−1, and independent validation of the model utilizing 206 spectra to create a model and 105 independent test spectra resulted in a correlation between the predicted and actual Collins grade of R2 = 0.8228 with a standard error of prediction of 0.258 with a PLS1 rank of 15 PLS factors. A preliminary PLS1 calibration that utilized a cross-validation technique to investigate the possibility of correlation with histological tissue grade (33 spectra from 18 tissues) resulted in R2 = 0.8408 using only eight PLS factors, a very encouraging outcome. Thus, the groundwork for use of IFOP-based chemometric determination of early cartilage degradation has been established.

Dephosphorylation of protamine 2 at serine 56 is crucial for murine sperm maturation in vivo

2019 ◽  
Vol 12 (574) ◽  
pp. eaao7232 ◽  
Author(s):  
Katsuhiko Itoh ◽  
Gen Kondoh ◽  
Hitoshi Miyachi ◽  
Manabu Sugai ◽  
Yoshiyuki Kaneko ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Sperm Maturation ◽  
Sperm Cells ◽  
Chromatin Binding ◽  
Wild Type ◽  
Underlying Mechanisms ◽  
Deficient Mice ◽  
Protamine 2

The posttranslational modification of histones is crucial in spermatogenesis, as in other tissues; however, during spermiogenesis, histones are replaced with protamines, which are critical for the tight packaging of the DNA in sperm cells. Protamines are also posttranslationally modified by phosphorylation and dephosphorylation, which prompted our investigation of the underlying mechanisms and biological consequences of their regulation. On the basis of a screen that implicated the heat shock protein Hspa4l in spermatogenesis, we generated mice deficient in Hspa4l (Hspa4l-null mice), which showed male infertility and the malformation of sperm heads. These phenotypes are similar to those of Ppp1cc-deficient mice, and we found that the amount of a testis- and sperm-specific isoform of the Ppp1cc phosphatase (Ppp1cc2) in the chromatin-binding fraction was substantially less in Hspa4l-null spermatozoa than that in those of wild-type mice. We further showed that Ppp1cc2 was a substrate of the chaperones Hsc70 and Hsp70 and that Hspa4l enhanced the release of Ppp1cc2 from these complexes, enabling the freed Ppp1cc2 to localize to chromatin. Pull-down and in vitro phosphatase assays suggested the dephosphorylation of protamine 2 at serine 56 (Prm2 Ser56) by Ppp1cc2. To confirm the biological importance of Prm2 Ser56 dephosphorylation, we mutated Ser56 to alanine in Prm2 (Prm2 S56A). Introduction of this mutation to Hspa4l-null mice (Hspa4l−/−; Prm2S56A/S56A) restored the malformation of sperm heads and the infertility of Hspa4l−/− mice. The dephosphorylation signal to eliminate phosphate was crucial, and these results unveiled the mechanism and biological relevance of the dephosphorylation of Prm2 for sperm maturation in vivo.

scholarly journals In vivo functional mapping of the conserved protein domains within murine Themis1

2014 ◽  
Vol 92 (8) ◽  
pp. 721-728 ◽  
Author(s):  
Ekaterina Zvezdova ◽  
Jan Lee ◽  
Dalal El‐Khoury ◽  
Valarie Barr ◽  
Itoro Akpan ◽  
...  
Keyword(s):  
Protein Domains ◽  
Functional Mapping

scholarly journals The Rett Syndrome Protein MeCP2 Regulates Synaptic Scaling

2012 ◽  
Vol 32 (3) ◽  
pp. 989-994 ◽  
Author(s):  
Z. Qiu ◽  
E. L. Sylwestrak ◽  
D. N. Lieberman ◽  
Y. Zhang ◽  
X.-Y. Liu ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Synaptic Scaling ◽  
Syndrome Protein ◽  
Protein Mecp2

scholarly journals Deficient Purposeful Use of Forepaws in Female Mice Modelling Rett Syndrome

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Bianca De Filippis ◽  
Mattia Musto ◽  
Luisa Altabella ◽  
Emilia Romano ◽  
Rossella Canese ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Motor Coordination ◽  
Neurodevelopmental Disorder ◽  
Fine Motor ◽  
Resonance Spectroscopy ◽  
Fine Motor Skill ◽  
Female Mice ◽  
Fine Grain ◽  
Motor Abnormalities

Rett syndrome (RTT) is a rare neurodevelopmental disorder, characterized by severe behavioural and physiological symptoms. Mutations in the methyl CpG binding protein 2 gene (MECP2) cause more than 95% of classic cases. Motor abnormalities represent a significant part of the spectrum of RTT symptoms. In the present study we investigated motor coordination and fine motor skill domains in MeCP2-308 female mice, a validated RTT model. This was complemented by thein vivomagnetic resonance spectroscopy (MRS) analysis of metabolic profile in behaviourally relevant brain areas. MeCP2-308 heterozygous female mice (Het, 10-12 months of age) were impaired in tasks validated for the assessment of purposeful and coordinated forepaw use (Morag testandCapellini handling task). A fine-grain analysis of spontaneous behaviour in the home-cage also revealed an abnormal handling pattern when interacting with the nesting material, reduced motivation to explore the environment, and increased time devoted to feeding in Het mice. The brain MRS evaluation highlighted decreased levels of bioenergetic metabolites in the striatal area in Het mice compared to controls. Present results confirm behavioural and brain alterations previously reported in MeCP2-308 males and identify novel endpoints on which the efficacy of innovative therapeutic strategies for RTT may be tested.

scholarly journals A mixed modality approach towards Xi reactivation for Rett syndrome and other X-linked disorders

2017 ◽  
Vol 115 (4) ◽  
pp. E668-E675 ◽  
Author(s):  
Lieselot L. G. Carrette ◽  
Chen-Yu Wang ◽  
Chunyao Wei ◽  
William Press ◽  
Weiyuan Ma ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Noncoding Rna ◽  
Cultured Cells ◽  
Fragile X ◽  
Specific Treatment ◽  
Disease Genes ◽  
X Chromosomes ◽  
Modality Approach ◽  
Mixed Modality

The X-chromosome harbors hundreds of disease genes whose associated diseases predominantly affect males. However, a subset, including neurodevelopmental disorders, Rett syndrome (RTT), fragile X syndrome, and CDKL5 syndrome, also affects females. These disorders lack disease-specific treatment. Because female cells carry two X chromosomes, an emerging treatment strategy has been to reawaken the healthy allele on the inactive X (Xi). Here, we focus on methyl-CpG binding protein 2 (MECP2) restoration for RTT and combinatorially target factors in the interactome of Xist, the noncoding RNA responsible for X inactivation. We identify a mixed modality approach combining an Xist antisense oligonucleotide and a small-molecule inhibitor of DNA methylation, which, together, achieve 30,000-fold MECP2 up-regulation from the Xi in cultured cells. Combining a brain-specific genetic Xist ablation with short-term 5-aza-2′-deoxycytidine (Aza) treatment models the synergy in vivo without evident toxicity. The Xi is selectively reactivated. These experiments provide proof of concept for a mixed modality approach for treating X-linked disorders in females.

scholarly journals Regulation of Rtt107 Recruitment to Stalled DNA Replication Forks by the Cullin Rtt101 and the Rtt109 Acetyltransferase

2008 ◽  
Vol 19 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Tania M. Roberts ◽  
Iram Waris Zaidi ◽  
Jessica A. Vaisica ◽  
Matthias Peter ◽  
Grant W. Brown
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Replication Forks ◽  
Chromatin Binding ◽  
Direct Role ◽  
Repair Enzymes ◽  
Damage Response ◽  
Stalled Replication Forks

RTT107 (ESC4, YHR154W) encodes a BRCA1 C-terminal domain protein that is important for recovery from DNA damage during S phase. Rtt107 is a substrate of the checkpoint kinase Mec1, and it forms complexes with DNA repair enzymes, including the nuclease subunit Slx4, but the role of Rtt107 in the DNA damage response remains unclear. We find that Rtt107 interacts with chromatin when cells are treated with compounds that cause replication forks to arrest. This damage-dependent chromatin binding requires the acetyltransferase Rtt109, but it does not require acetylation of the known Rtt109 target, histone H3-K56. Chromatin binding of Rtt107 also requires the cullin Rtt101, which seems to play a direct role in Rtt107 recruitment, because the two proteins are found in complex with each other. Finally, we provide evidence that Rtt107 is bound at or near stalled replication forks in vivo. Together, these results indicate that Rtt109, Rtt101, and Rtt107, which genetic evidence suggests are functionally related, form a DNA damage response pathway that recruits Rtt107 complexes to damaged or stalled replication forks.

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