scholarly journals Diminished miRNA activity is associated with aberrant cytoplasmic intron retention in ALS pathogenesis

2021 ◽  
Author(s):  
Marija Petric-Howe ◽  
Hamish Crerar ◽  
Jacob Neeves ◽  
Giulia E. Tyzack ◽  
Rickie Patani ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Target Genes ◽  
Intron Retention ◽  
Spatiotemporal Dynamics ◽  
Expression Level ◽  
Mechanistic Insight ◽  
Selective Increase ◽  
Insight Into

SUMMARYIntron retention (IR) is now recognized as a dominant splicing event during motor neuron (MN) development, however the role and regulation of intron-retaining transcripts (IRTs) localized to the cytoplasm remain particularly understudied. By resolving the spatiotemporal dynamics of IR underlying distinct stages of MN lineage restriction, we identify a cytoplasmic group of IRTs that is not associated with reduced expression of their own genes but instead with an upregulation of predicted target genes of specific miRNAs, the motifs of which are enriched within the intronic sequences of this group. Next, we show that ALS-causing VCP mutations lead to a selective increase in IR of this particular class of introns. This in turn temporally coincides with an increase in the expression level of predicted target genes of these miRNAs, providing a potential mechanistic insight into ALS pathogenesis. Altogether, we propose a novel role for the cytoplasmic intronic sequences in regulating miRNA activity through miRNA sequestration, which potentially contributes to ALS pathogenesis.

scholarly journals Histone H3K23-specific acetylation by MORF is coupled to H3K14 acylation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Suk Min Jang ◽  
Catherine Lachance ◽  
Wenyi Mi ◽  
Jie Lyu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Memory Impairment ◽  
Target Genes ◽  
Epigenetic Mark ◽  
Mechanistic Insight ◽  
Genomic Analyses ◽  
Insight Into

Abstract Acetylation of histone H3K23 has emerged as an essential posttranslational modification associated with cancer and learning and memory impairment, yet our understanding of this epigenetic mark remains insufficient. Here, we identify the native MORF complex as a histone H3K23-specific acetyltransferase and elucidate its mechanism of action. The acetyltransferase function of the catalytic MORF subunit is positively regulated by the DPF domain of MORF (MORFDPF). The crystal structure of MORFDPF in complex with crotonylated H3K14 peptide provides mechanistic insight into selectivity of this epigenetic reader and its ability to recognize both histone and DNA. ChIP data reveal the role of MORFDPF in MORF-dependent H3K23 acetylation of target genes. Mass spectrometry, biochemical and genomic analyses show co-existence of the H3K23ac and H3K14ac modifications in vitro and co-occupancy of the MORF complex, H3K23ac, and H3K14ac at specific loci in vivo. Our findings suggest a model in which interaction of MORFDPF with acylated H3K14 promotes acetylation of H3K23 by the native MORF complex to activate transcription.

scholarly journals GLI1/GLI2 functional interplay is required to control Hedgehog/GLI targets gene expression

2020 ◽  
Vol 477 (17) ◽  
pp. 3131-3145 ◽  
Author(s):  
Ezequiel J. Tolosa ◽  
Maite G. Fernandez-Barrena ◽  
Eriko Iguchi ◽  
Angela L. McCleary-Wheeler ◽  
Ryan M. Carr ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Chromatin Immunoprecipitation ◽  
Target Genes ◽  
Large Set ◽  
Gli Proteins ◽  
Pancreatic Cancer Cells ◽  
Mechanistic Insight ◽  
Mapping Analysis ◽  
First Time ◽  
Insight Into

The Hedgehog-regulated transcription factors GLI1 and GLI2 play overlapping roles in development and disease; however, the mechanisms underlying their interplay remain elusive. We report for the first time that GLI1 and GLI2 physically and functionally interact in cancer cells. GLI1 and GLI2 were shown to co-immunoprecipitate in PANC1 pancreatic cancer cells and RMS13 rhabdomyosarcoma cells. Mapping analysis demonstrated that the zinc finger domains of both proteins are required for their heteromerization. RNAi knockdown of either GLI1 or GLI2 inhibited expression of many well-characterized GLI target genes (BCL2, MYCN, PTCH2, IL7 and CCND1) in PANC1 cells, whereas PTCH1 expression was only inhibited by GLI1 depletion. qPCR screening of a large set of putative canonical and non-canonical Hedgehog/GLI targets identified further genes (e.g. E2F1, BMP1, CDK2) strongly down-regulated by GLI1 and/or GLI2 depletion in PANC1 cells, and demonstrated that ANO1, AQP1 and SOCS1 are up-regulated by knockdown of either GLI1 or GLI2. Chromatin immunoprecipitation showed that GLI1 and GLI2 occupied the same regions at the BCL2, MYCN and CCND1 promoters. Furthermore, depletion of GLI1 inhibited GLI2 occupancy at these promoters, suggesting that GLI1/GLI2 interaction is required for the recruitment of GLI2 to these sites. Together, these findings indicate that GLI1 and GLI2 co-ordinately regulate the transcription of some genes, and provide mechanistic insight into the roles of GLI proteins in carcinogenesis.

scholarly journals Mechanistic insight into B(C6F5)3 catalyzed imine reduction with PhSiH3 under stoichiometric water conditions

RSC Advances ◽  
2021 ◽  
Vol 11 (34) ◽  
pp. 20961-20969
Author(s):  
Yunqing He ◽  
Wanli Nie ◽  
Ying Xue ◽  
Qishan Hu
Keyword(s):  
Mechanistic Insight ◽  
Excess Water ◽  
Water Conditions ◽  
Imine Reduction ◽  
Water Amount ◽  
Insight Into

Hydrosilylation or amination products? It depends on water amount and nucleophiles like excess water or produced/added amines.

scholarly journals Mechanistic insight into the fluorescence activity of forensic fingerprinting reagents

2021 ◽  
Vol 154 (12) ◽  
pp. 124313
Author(s):  
L. M. Hunnisett ◽  
P. F. Kelly ◽  
S. Bleay ◽  
F. Plasser ◽  
R. King ◽  
...  
Keyword(s):  
Mechanistic Insight ◽  
Insight Into

scholarly journals Alternative splicing landscapes in Arabidopsis thaliana across tissues and stress conditions highlight major functional differences with animals

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guiomar Martín ◽  
Yamile Márquez ◽  
Federica Mantica ◽  
Paula Duque ◽  
Manuel Irimia
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Alternative Splicing ◽  
Stress Responses ◽  
Target Genes ◽  
Intron Retention ◽  
Single Gene ◽  
Exon Skipping ◽  
Environmental Response ◽  
Biotic Stresses

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.

Sign in / Sign up

Export Citation Format

Share Document