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Full-Text Articles in Medicine and Health Sciences

Nanorings To Probe Mechanical Stress Of Single-Stranded Dna Mediated By The Dna Duplex, Karen Zagorski, Tommy Stormberg, Mohtadin Hashemi, Anatoly B. Kolomeisky, Yuri L. Lyubchenko Jan 2022

Nanorings To Probe Mechanical Stress Of Single-Stranded Dna Mediated By The Dna Duplex, Karen Zagorski, Tommy Stormberg, Mohtadin Hashemi, Anatoly B. Kolomeisky, Yuri L. Lyubchenko

Journal Articles: Pharmaceutical Sciences

The interplay between the mechanical properties of double-stranded and single-stranded DNA is a phenomenon that contributes to various genetic processes in which both types of DNA structures coexist. Highly stiff DNA duplexes can stretch single-stranded DNA (ssDNA) segments between the duplexes in a topologically constrained domain. To evaluate such an effect, we designed short DNA nanorings in which a DNA duplex with 160 bp is connected by a 30 nt single-stranded DNA segment. The stretching effect of the duplex in such a DNA construct can lead to the elongation of ssDNA, and this effect can be measured directly using atomic …


Samhd1 Is A Single-Stranded Nucleic Acid Binding Protein With No Active Site-Associated Nuclease Activity., Kyle J. Seamon, Zhiqiang Sun, Luda S. Shlyakhtenko, Yuri L. Lyubchenko, James T. Stivers Jul 2015

Samhd1 Is A Single-Stranded Nucleic Acid Binding Protein With No Active Site-Associated Nuclease Activity., Kyle J. Seamon, Zhiqiang Sun, Luda S. Shlyakhtenko, Yuri L. Lyubchenko, James T. Stivers

Journal Articles: Pharmaceutical Sciences

The HIV-1 restriction factor SAMHD1 is a tetrameric enzyme activated by guanine nucleotides with dNTP triphosphate hydrolase activity (dNTPase). In addition to this established activity, there have been a series of conflicting reports as to whether the enzyme also possesses single-stranded DNA and/or RNA 3'-5' exonuclease activity. SAMHD1 was purified using three chromatography steps, over which the DNase activity was largely separated from the dNTPase activity, but the RNase activity persisted. Surprisingly, we found that catalytic and nucleotide activator site mutants of SAMHD1 with no dNTPase activity retained the exonuclease activities. Thus, the exonuclease activity cannot be associated with any …


Bridged Filaments Of Histone-Like Nucleoid Structuring Protein Pause Rna Polymerase And Aid Termination In Bacteria., Matthew V. Kotlajich, Daniel R. Hron, Beth A. Boudreau, Zhiqiang Sun, Yuri L. Lyubchenko, Robert Landick Jan 2015

Bridged Filaments Of Histone-Like Nucleoid Structuring Protein Pause Rna Polymerase And Aid Termination In Bacteria., Matthew V. Kotlajich, Daniel R. Hron, Beth A. Boudreau, Zhiqiang Sun, Yuri L. Lyubchenko, Robert Landick

Journal Articles: Pharmaceutical Sciences

Bacterial H-NS forms nucleoprotein filaments that spread on DNA and bridge distant DNA sites. H-NS filaments co-localize with sites of Rho-dependent termination in Escherichia coli, but their direct effects on transcriptional pausing and termination are untested. In this study, we report that bridged H-NS filaments strongly increase pausing by E. coli RNA polymerase at a subset of pause sites with high potential for backtracking. Bridged but not linear H-NS filaments promoted Rho-dependent termination by increasing pause dwell times and the kinetic window for Rho action. By observing single H-NS filaments and elongating RNA polymerase molecules using atomic force microscopy, we …


Human Rna Polymerase Ii-Association Factor 1 (Hpaf1/Pd2) Regulates Histone Methylation And Chromatin Remodeling In Pancreatic Cancer., Parama Dey, Moorthy P. Ponnusamy, Shonali Deb, Surinder K. Batra Oct 2011

Human Rna Polymerase Ii-Association Factor 1 (Hpaf1/Pd2) Regulates Histone Methylation And Chromatin Remodeling In Pancreatic Cancer., Parama Dey, Moorthy P. Ponnusamy, Shonali Deb, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

Change in gene expression associated with pancreatic cancer could be attributed to the variation in histone posttranslational modifications leading to subsequent remodeling of the chromatin template during transcription. However, the interconnected network of molecules involved in regulating such processes remains elusive. hPaf1/PD2, a subunit of the human PAF-complex, involved in the regulation of transcriptional elongation has oncogenic potential. Our study explores the possibility that regulation of histone methylation by hPaf1 can contribute towards alteration in gene expression by nucleosomal rearrangement. Here, we show that knockdown of hPaf1/PD2 leads to decreased di- and tri-methylation at histone H3 lysine 4 residues in …


Renal Thrombotic Microangiopathy In Mice With Combined Deletion Of Endocytic Recycling Regulators Ehd3 And Ehd4., Manju George, Mark A. Rainey, Mayumi Naramura, Kirk W. Foster, Melissa S. Holzapfel, Laura L. Willoughby, Guoguang Ying, Rasna M. Goswami, Channabasavaiah B. Gurumurthy, Vimla Band, Simon C. Satchell, Hamid Band Mar 2011

Renal Thrombotic Microangiopathy In Mice With Combined Deletion Of Endocytic Recycling Regulators Ehd3 And Ehd4., Manju George, Mark A. Rainey, Mayumi Naramura, Kirk W. Foster, Melissa S. Holzapfel, Laura L. Willoughby, Guoguang Ying, Rasna M. Goswami, Channabasavaiah B. Gurumurthy, Vimla Band, Simon C. Satchell, Hamid Band

Journal Articles: Eppley Institute

Eps15 Homology Domain-containing 3 (EHD3), a member of the EHD protein family that regulates endocytic recycling, is the first protein reported to be specifically expressed in the glomerular endothelium in the kidney; therefore we generated Ehd3(-/-) mice and assessed renal development and pathology. Ehd3(-/-) animals showed no overt defects, and exhibited no proteinuria or glomerular pathology. However, as the expression of EHD4, a related family member, was elevated in the glomerular endothelium of Ehd3(-/-) mice and suggested functional compensation, we generated and analyzed Ehd3(-/-); Ehd4(-/-) mice. These mice were smaller, possessed smaller and paler kidneys, were proteinuric and died between …


The Notch Regulator Maml1 Interacts With P53 And Functions As A Coactivator., Yongtong Zhao, Rebecca B. Katzman, Laurie M. Delmolino, Ishfaq Bhat, Ying Zhang, Channabasavaiah B. Gurumurthy, Aleksandra Germaniuk-Kurowska, Honey V. Reddi, Aharon Solomon, Mu-Sheng Zeng, Aisha Kung, Hui Ma, Qingshen Gao, Goberdhan Dimri, Adina Stanculescu, Lucio Miele, Lizi Wu, James D. Griffin, David E. Wazer, Hamid Band, Vimla Band Apr 2007

The Notch Regulator Maml1 Interacts With P53 And Functions As A Coactivator., Yongtong Zhao, Rebecca B. Katzman, Laurie M. Delmolino, Ishfaq Bhat, Ying Zhang, Channabasavaiah B. Gurumurthy, Aleksandra Germaniuk-Kurowska, Honey V. Reddi, Aharon Solomon, Mu-Sheng Zeng, Aisha Kung, Hui Ma, Qingshen Gao, Goberdhan Dimri, Adina Stanculescu, Lucio Miele, Lizi Wu, James D. Griffin, David E. Wazer, Hamid Band, Vimla Band

Journal Articles: Biochemistry & Molecular Biology

Members of the evolutionarily conserved Mastermind (MAM) protein family, including the three related mammalian Mastermind-like (MAML) proteins MAML1-3, function as crucial coactivators of Notch-mediated transcriptional activation. Given the recent evidence of cross-talk between the p53 and Notch signal transduction pathways, we have investigated whether MAML1 may also be a transcriptional coactivator of p53. Indeed, we show here that MAML1 is able to interact with p53. We show that MAML1-p53 interaction involves the N-terminal region of MAML1 and the DNA-binding domain of p53, and we use a chromatin immunoprecipitation assay to show that MAML1 is part of the activator complex that …