Medicine and Health Sciences Commons^™

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. …

Epigenetic Etiology Of Intellectual Disability., Shigeki Iwase, Nathalie G Bérubé, Zhaolan Zhou, Nael Nadif Kasri, Elena Battaglioli, Marilyn Scandaglia, Angel Barco

Paediatrics Publications

Intellectual disability (ID) is a prevailing neurodevelopmental condition associated with impaired cognitive and adaptive behaviors. Many chromatin-modifying enzymes and other epigenetic regulators have been genetically associated with ID disorders (IDDs). Here we review how alterations in the function of histone modifiers, chromatin remodelers, and methyl-DNA binding proteins contribute to neurodevelopmental defects and altered brain plasticity. We also discuss how progress in human genetics has led to the generation of mouse models that unveil the molecular etiology of ID, and outline the direction in which this field is moving to identify therapeutic strategies for IDDs. Importantly, because the chromatin regulators linked …

Epigenetic Suppression Of Hippocampal Calbindin-D28k By Δfosb Drives Seizure-Related Cognitive Deficits., Jason C. You, Kavitha Muralidharan, Jin W. Park, Iraklis Petrof, Mark S. Pyfer, Brian F. Corbett, John J. Lafrancois, Yi Zheng, Xiaohong Zhang, Carrie A. Mohila, Daniel Yoshor, Robert A. Rissman, Eric J. Nestler, Helen E. Scharfman, Jeannie Chin

Department of Neuroscience Faculty Papers

The calcium-binding protein calbindin-D28k is critical for hippocampal function and cognition, but its expression is markedly decreased in various neurological disorders associated with epileptiform activity and seizures. In Alzheimer's disease (AD) and epilepsy, both of which are accompanied by recurrent seizures, the severity of cognitive deficits reflects the degree of calbindin reduction in the hippocampal dentate gyrus (DG). However, despite the importance of calbindin in both neuronal physiology and pathology, the regulatory mechanisms that control its expression in the hippocampus are poorly understood. Here we report an epigenetic mechanism through which seizures chronically suppress hippocampal calbindin expression and impair cognition. …

Heterozygous De Novo Ubtf Gain-Of-Function Variant Is Associated With Neurodegeneration In Childhood., Simon Edvardson, Claudia M Nicolae, Pankaj B Agrawal, Cyril Mignot, Katelyn Payne, Asuri Narayan Prasad, Chitra Prasad, Laurie Sadler, Caroline Nava, Thomas E Mullen, Amber Begtrup, Berivan Baskin, Zöe Powis, Avraham Shaag, Boris Keren, George-Lucian Moldovan, Orly Elpeleg

Paediatrics Publications

Ribosomal RNA (rRNA) is transcribed from rDNA by RNA polymerase I (Pol I) to produce the 45S precursor of the 28S, 5.8S, and 18S rRNA components of the ribosome. Two transcription factors have been defined for Pol I in mammals, the selectivity factor SL1, and the upstream binding transcription factor (UBF), which interacts with the upstream control element to facilitate the assembly of the transcription initiation complex including SL1 and Pol I. In seven unrelated affected individuals, all suffering from developmental regression starting at 2.5-7 years, we identified a heterozygous variant, c.628G>A in UBTF, encoding p.Glu210Lys in UBF, which …

Loss Of Resistance To Angiotensin Ii-Induced Hypertension In The Jackson Laboratory Recombination-Activating Gene Null Mouse On The C57bl/6j Background, Hong Ji, Amrita V Pai, Crystal A West, Xie Wu, Robert Charles Speth, Kathryn Sandberg

Faculty Articles

Resistance to angiotensin II (Ang II)–induced hypertension in T-cell–deficient male mice with a targeted mutation in the recombination-activating gene-1 (Rag1) on the C57BL/6J background (B6.Rag1^−/−-M), which was reported by 5 independent laboratories including ours before 2015, has been lost. In mice purchased from Jackson Laboratory in 2015 and 2016, the time course and magnitude increase in mean arterial pressure induced by 2 weeks of Ang II infusion at 490 ng/kg per minute was identical between B6.Rag1^−/−-M and male wild-type littermates. Moreover, there were no differences in the time course or magnitude increase …

Genome- And Cd4+ T-Cell Methylome-Wide Association Study Of Circulating Trimethylamine-N-Oxide In The Genetics Of Lipid Lowering Drugs And Diet Network (Goldn), Stella Aslibekyan, Marguerite R. Irvin, Bertha A. Hidalgo, Rodney T. Perry, Elias J. Jeyarajah, Erwin Garcia, Irina Shalaurova, Paul N. Hopkins, Michael A. Province, Hemant K. Tiwari, Jose M. Ordovas, Devin M. Absher, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background: Trimethylamine-N-oxide (TMAO), an atherogenic metabolite species, has emerged as a possible new risk factor for cardiovascular disease. Animal studies have shown that circulating TMAO levels are regulated by genetic and environmental factors. However, large-scale human studies have failed to replicate the observed genetic associations, and epigenetic factors such as DNA methylation have never been examined in relation to TMAO levels.

Methods and results: We used data from the family-based Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) to investigate the heritable determinants of plasma TMAO in humans. TMAO was not associated with other plasma markers of cardiovascular disease, …

The Transcriptional Regulation Of The Human Angiotensinogen Gene After High-Fat Diet Is Haplotype-Dependent: Novel Insights Into The Gene-Regulatory Networks And Implications For Human Hypertension, A Rana, S Jain, N Puri, M Kaw, N Sirianni, D Eren, Brahma Mopidevi, Anand Kumar

NYMC Faculty Publications

Single nucleotide polymorphisms (SNPs) in the human angiotensinogen (hAGT) gene may modulate its transcription and affect the regulation of blood pressure via activation of the renin-angiotensin aldosterone system (RAAS). In this regard, we have identified polymorphisms in the 2.5 Kb promoter of the hAGT gene that form two haplotype (Hap) blocks: -6A/G (-1670A/G, -1562C/T, -1561T/C) and -217A/G (-532T/C, -793A/G, -1074T/C & -1178G/A). hAGT gene with Hap -6A/-217A (Hap I) is associated with increased blood pressure whereas, Hap -6G/-217G (Hap II) is associated with normal blood pressure in human subjects. Since RAAS over activity contributes to hypertension in obesity, we have …

Identification Of Epigenetic Signature Associated With Alpha Thalassemia/Mental Retardation X-Linked Syndrome, Laila C Schenkel, Kristin D Kernohan, Arran Mcbride, Ditta Reina, Amanda Hodge, Peter J Ainsworth, David I Rodenhiser, Guillaume Pare, Nathalie G Bérubé, Cindy Skinner, Kym M Boycott, Charles Schwartz, Bekim Sadikovic

Paediatrics Publications

BACKGROUND: Alpha thalassemia/mental retardation X-linked syndrome (ATR-X) is caused by a mutation at the chromatin regulator gene

RESULTS: We performed genome-wide DNA methylation assessment of the peripheral blood samples from 18 patients with ATR-X and compared it to 210 controls. We demonstrated the evidence of a unique and highly specific DNA methylation "epi-signature" in the peripheral blood of ATRX patients, which was corroborated by targeted bisulfite sequencing experiments. Although genomically represented, differentially methylated regions showed evidence of preferential clustering in pericentromeric and telometric chromosomal regions, areas where ATRX has multiple functions related to maintenance of heterochromatin and genomic integrity.

CONCLUSION: …