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In-Depth Sequence Analysis of Bread Wheat VRN1 Genes.
Strejčková, B, Milec, Z, Holušová, K, Cápal, P, Vojtková, T, Čegan, R, Šafář, J
International journal of molecular sciences. 2021;(22)
Abstract
The VERNALIZATION1 (VRN1) gene encodes a MADS-box transcription factor and plays an important role in the cold-induced transition from the vegetative to reproductive stage. Allelic variability of VRN1 homoeologs has been associated with large differences in flowering time. The aim of this study was to investigate the genetic variability of VRN1 homoeologs (VRN-A1, VRN-B1 and VRN-D1). We performed an in-depth sequence analysis of VRN1 homoeologs in a panel of 105 winter and spring varieties of hexaploid wheat. We describe the novel allele Vrn-B1f with an 836 bp insertion within intron 1 and show its specific expression pattern associated with reduced heading time. We further provide the complete sequence of the Vrn-A1b allele, revealing a 177 bp insertion in intron 1, which is transcribed into an alternative splice variant. Copy number variation (CNV) analysis of VRN1 homoeologs showed that VRN-B1 and VRN-D1 are present in only one copy. The copy number of recessive vrn-A1 ranged from one to four, while that of dominant Vrn-A1 was one or two. Different numbers of Vrn-A1a copies in the spring cultivars Branisovicka IX/49 and Bastion did not significantly affect heading time. We also report on the deletion of secondary structures (G-quadruplex) in promoter sequences of cultivars with more vrn-A1 copies.
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Tissue-specific DNase I footprint analysis confirms the association of GATAD2B Q470* variant with intellectual disability.
Nikam, V, Shaik Mohammad, N
Journal of genetics. 2021
Abstract
Intellectual disability (ID) is a neurodevelopmental disorder in which genetics play a key aetiological role. GATA zinc finger domain-containing 2B (GATAD2B) gene encodes a zinc-finger protein transcriptional repressor which is a part of the methyl-CpG binding protein-1 complex. Pathogenic variants in this gene are linked to ID, dysmorphic features, and cognitive disability. To date, only 18 cases are reported worldwide and only one case is reported from India. A 12-year-old girl presented with a heterozygous nonsense variation in exon 8 of the GATAD2B gene (chr1:153785737G>A). She has severe ID and significant delayed developmental milestones along with clinical features including broad arched eyebrows, low-set ears, a bulbous nose tip, thin upper lip, and wide mouth with downturned corners. This is the second report of a heterozygous mutation in the GATAD2B gene from India with a novel phenotype. To substantiate the association of GATAD2B mutation with ID, we performed DNase I footprint analysis of wild and mutant DNA sequences to establish k-mer binding profile and deduced GATA binding affinity using human ENCODE experimental data of foetal brain. We observed that in the presence of variation, GATA zinc finger domain was altered thus contributing to ID. Our findings support the importance of the GATAD2B gene in the study of neurodevelopmental disorders.
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AHRR methylation in heavy smokers: associations with smoking, lung cancer risk, and lung cancer mortality.
Grieshober, L, Graw, S, Barnett, MJ, Thornquist, MD, Goodman, GE, Chen, C, Koestler, DC, Marsit, CJ, Doherty, JA
BMC cancer. 2020;(1):905
Abstract
BACKGROUND A low level of methylation at cg05575921 in the aryl-hydrocarbon receptor repressor (AHRR) gene is robustly associated with smoking, and some studies have observed associations between cg05575921 methylation and increased lung cancer risk and mortality. To prospectively examine whether decreased methylation at cg05575921 may identify high risk subpopulations for lung cancer screening among heavy smokers, and mortality in cases, we evaluated associations between cg05575921 methylation and lung cancer risk and mortality, by histotype, in heavy smokers. METHODS The β-Carotene and Retinol Efficacy Trial (CARET) included enrollees ages 45-69 with ≥ 20 pack-year smoking histories and/or occupational asbestos exposure. A subset of CARET participants had cg05575921 methylation available from HumanMethylationEPIC assays of blood collected on average 4.3 years prior to lung cancer diagnosis in cases. Cg05575921 methylation β-values were treated continuously for a 10% methylation decrease and as quintiles, where quintile 1 (Q1, referent) represents high methylation and Q5, low methylation. We used conditional logistic regression models to examine lung cancer risk overall and by histotype in a nested case-control study including 316 lung cancer cases (diagnosed through 2005) and 316 lung cancer-free controls matched on age (±5 years), sex, race/ethnicity, enrollment year, current/former smoking, asbestos exposure, and follow-up time. Mortality analyses included 372 lung cancer cases diagnosed between 1985 and 2013 with available methylation data. We used Cox proportional hazards models to examine mortality overall and by histotype. RESULTS Decreased cg05575921 methylation was strongly associated with smoking, even in our population of heavy smokers. We did not observe associations between decreased pre-diagnosis cg05575921 methylation and increased lung cancer risk, overall or by histotype. We observed linear increasing trends for lung cancer-specific mortality across decreasing cg05575921 methylation quintiles for adenocarcinoma and small cell carcinoma (P-trends = 0.01 and 0.04, respectively). CONCLUSIONS In our study of heavy smokers, decreased cg05575921 methylation was strongly associated with smoking but not increased lung cancer risk. The observed association between cg05575921 methylation and increased mortality in adenocarcinoma and small cell histotypes requires further examination. Our results do not support using decreased cg05575921 methylation as a biomarker for lung cancer screening risk stratification.
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Dynamic Signatures of the Epigenome: Friend or Foe?
Machnik, M, Oleksiewicz, U
Cells. 2020;(3)
Abstract
Highly dynamic epigenetic signaling is influenced mainly by (micro)environmental stimuli and genetic factors. The exact mechanisms affecting particular epigenomic patterns differ dependently on the context. In the current review, we focus on the causes and effects of the dynamic signatures of the human epigenome as evaluated with the high-throughput profiling data and single-gene approaches. We will discuss three different aspects of phenotypic outcomes occurring as a consequence of epigenetics interplaying with genotype and environment. The first issue is related to the cases of environmental impacts on epigenetic profile, and its adverse and advantageous effects related to human health and evolutionary adaptation. The next topic will present a model of the interwoven co-evolution of genetic and epigenetic patterns exemplified with transposable elements (TEs) and their epigenetic repressors Krüppel-associated box zinc finger proteins (KRAB-ZNFs). The third aspect concentrates on the mitosis-based microevolution that takes place during carcinogenesis, leading to clonal diversity and expansion of tumor cells. The whole picture of epigenome plasticity and its role in distinct biological processes is still incomplete. However, accumulating data define epigenomic dynamics as an essential co-factor driving adaptation at the cellular and inter-species levels with a benefit or disadvantage to the host.
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[Progress in Role of FEZF1-AS1 in Non-small Cell Lung Cancer].
Chen, J, Yin, R, Liu, X
Zhongguo fei ai za zhi = Chinese journal of lung cancer. 2020;(4):294-298
Abstract
Nowadays, accumulating evidence indicates that long non-coding RNA (lncRNA) play vital roles in tumorigenesis. As a newly discovered lncRNA, FEZ family zinc finger 1-antisense RNA 1 (FEZF1-AS1) is markedly upregulated in various malignant tumors including non-small cell lung cancer (NSCLC). Aberrant expression of FEZF1-AS1 is related to clinical characteristics of patients with NSCLC and suggests poor prognosis. Moreover, FEZF1-AS1 can regulate numerous biological processes, such as cell proliferation, migration and invasion through different mechanisms. In this article, we systematically summarize the recent research progress of FEZF1-AS1 in NSCLC, which might be a novel target for clinical therapy.
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ASXL1 mutation confers poor prognosis in primary myelofibrosis patients with low JAK2V617F allele burden but not in those with high allele burden.
Wang, YH, Lin, CC, Lee, SH, Tsai, CH, Wu, SJ, Hou, HA, Huang, TC, Kuo, YY, Yao, M, Chang, K, et al
Blood cancer journal. 2020;(10):99
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7.
Pseudokinases: a tribble-edged sword.
Richmond, L, Keeshan, K
The FEBS journal. 2020;(19):4170-4182
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Abstract
Advances in the understanding of the Tribbles family of pseudokinases (TRIB1, TRIB2 and TRIB3) reveal these proteins as potentially valuable biomarkers of disease diagnosis, prognosis, prediction and clinical strategy. In their role as signalling mediators and scaffolding proteins, TRIBs lead to changes in protein stability and activity, which impact on diverse cellular processes such as proliferation, differentiation, cell cycle and cell death. We review the role of TRIB proteins as promising therapeutic targets, with an emphasis on their role in cancer, and as biomarkers, with potential application across diverse pathological processes.
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The protonation state of an evolutionarily conserved histidine modulates domainswapping stability of FoxP1.
Medina, E, Villalobos, P, Coñuecar, R, Ramírez-Sarmiento, CA, Babul, J
Scientific reports. 2019;(1):5441
Abstract
Forkhead box P (FoxP) proteins are members of the versatile Fox transcription factors, which control the timing and expression of multiple genes for eukaryotic cell homeostasis. Compared to other Fox proteins, they can form domain-swapped dimers through their DNA-binding -forkhead- domains, enabling spatial reorganization of distant chromosome elements by tethering two DNA molecules together. Yet, domain swapping stability and DNA binding affinity varies between different FoxP proteins. Experimental evidence suggests that the protonation state of a histidine residue conserved in all Fox proteins is responsible for pH-dependent modulation of these interactions. Here, we explore the consequences of the protonation state of another histidine (H59), only conserved within FoxM/O/P subfamilies, on folding and dimerization of the forkhead domain of human FoxP1. Dimer dissociation kinetics and equilibrium unfolding experiments demonstrate that protonation of H59 leads to destabilization of the domain-swapped dimer due to an increase in free energy difference between the monomeric and transition states. This pH-dependence is abolished when H59 is mutated to alanine. Furthermore, anisotropy measurements and molecular dynamics evidence that H59 has a direct impact in the local stability of helix H3. Altogether, our results highlight the relevance of H59 in domain swapping and folding stability of FoxP1.
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1H, 13C, and 15N resonance assignments of the C-terminal lobe of the human HECT E3 ubiquitin ligase ITCH.
Beasley, SA, Bardhi, R, Spratt, DE
Biomolecular NMR assignments. 2019;(1):15-20
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Abstract
ITCH (aka Atrophin-1-interacting protein 4) is a prominent member of the NEDD4 HECT (Homologous to E6AP C-Terminus) E3 ubiquitin ligase family that regulates numerous cellular functions including inflammatory responses through T-cell activation, cell differentiation, and apoptosis. Known intracellular targets of ITCH-dependent ubiquitylation include receptor proteins, signaling molecules, and transcription factors. The HECT C-terminal lobe of ITCH contains the conserved catalytic cysteine required for the covalent attachment of ubiquitin onto a substrate and polyubiquitin chain assembly. We report here the complete experimentally determined 1H, 13C, and 15N backbone and sidechain resonance assignments for the HECT C-terminal lobe of ITCH (residues 784-903) using heteronuclear, multidimensional NMR spectroscopy. These resonance assignments will be used in future NMR-based studies to examine the role of dynamics and conformational flexibility in HECT-dependent ubiquitylation as well as deciphering the structural and biochemical basis for polyubiquitin chain synthesis and specificity by ITCH.
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10.
Global Regulation by CsrA and Its RNA Antagonists.
Romeo, T, Babitzke, P
Microbiology spectrum. 2018;(2)
Abstract
The sequence-specific RNA binding protein CsrA is employed by diverse bacteria in the posttranscriptional regulation of gene expression. Its binding interactions with RNA have been documented at atomic resolution and shown to alter RNA secondary structure, RNA stability, translation, and/or Rho-mediated transcription termination through a growing number of molecular mechanisms. In Gammaproteobacteria, small regulatory RNAs (sRNAs) that contain multiple CsrA binding sites compete with mRNA for binding to CsrA, thereby sequestering and antagonizing this protein. Both the synthesis and turnover of these sRNAs are regulated, allowing CsrA activity to be rapidly and efficiently adjusted in response to nutritional conditions and stresses. Feedback loops between the Csr regulatory components improve the dynamics of signal response by the Csr system. The Csr system of Escherichia coli is intimately interconnected with other global regulatory systems, permitting it to contribute to regulation by those systems. In some species, a protein antagonist of CsrA functions as part of a checkpoint for flagellum biosynthesis. In other species, a protein antagonist participates in a mechanism in which a type III secretion system is used for sensing interactions with host cells. Recent transcriptomics studies reveal vast effects of CsrA on gene expression through direct binding to hundreds of mRNAs, and indirectly through its effects on the expression of dozens of transcription factors. CsrA binding to base-pairing sRNAs and novel mRNA segments, such as the 3' untranslated region and deep within coding regions, predict its participation in yet-to-be-discovered regulatory mechanisms.