Medicine and Health Sciences Commons^™

Relative Contributions Of Enterococcus Faecalis Og1rf Sortase-Encoding Genes, Srta And Bps (Srtc), To Biofilm Formation And A Murine Model Of Urinary Tract Infection, Kelvin D Kemp, Kavindra V Singh, Sreedhar R Nallapareddy, Barbara E Murray

Journal Articles

Deletion mutants of the two sortase genes of Enterococcus faecalis OG1RF were constructed. srtC (renamed here bps for biofilm and pilus-associated sortase) was previously shown to be necessary for the production of Ebp pili and important for biofilm formation and endocarditis. Here, we report that a srtA deletion mutant showed a small (5%) yet significant (P = 0.037) reduction in biofilm relative to OG1RF, while a DeltasrtA Deltabps double mutant showed a much greater reduction (74% versus OG1RF and 44% versus the Deltabps mutant). In a murine urinary tract infection (UTI), the 50% infective doses of both the DeltasrtA Deltabps …

Human Tob, An Antiproliferative Transcription Factor, Is A Poly(A)-Binding Protein-Dependent Positive Regulator Of Cytoplasmic Mrna Deadenylation, Nader Ezzeddine, Tsung-Cheng Chang, Wenmiao Zhu, Akio Yamashita, Chyi-Ying A Chen, Zhenping Zhong, Yukiko Yamashita, Dinghai Zheng, Ann-Bin Shyu

Journal Articles

In mammalian cells, mRNA decay begins with deadenylation, which involves two consecutive phases mediated by the PAN2-PAN3 and the CCR4-CAF1 complexes, respectively. The regulation of the critical deadenylation step and its relationship with RNA-processing bodies (P-bodies), which are thought to be a site where poly(A)-shortened mRNAs get degraded, are poorly understood. Using the Tet-Off transcriptional pulsing approach to investigate mRNA decay in mouse NIH 3T3 fibroblasts, we found that TOB, an antiproliferative transcription factor, enhances mRNA deadenylation in vivo. Results from glutathione S-transferase pull-down and coimmunoprecipitation experiments indicate that TOB can simultaneously interact with the poly(A) nuclease complex CCR4-CAF1 and …

Mutations In The Cofilin Partner Aip1/Wdr1 Cause Autoinflammatory Disease And Macrothrombocytopenia., Benjamin T Kile, Athanasia D Panopoulos, Roslynn A Stirzaker, Douglas F Hacking, Lubna H Tahtamouni, Tracy A Willson, Lisa A Mielke, Katya J Henley, Jian-Guo Zhang, Ian P Wicks, William S Stevenson, Paquita Nurden, Stephanie S Watowich, Monica J Justice

Journal Articles

A pivotal mediator of actin dynamics is the protein cofilin, which promotes filament severing and depolymerization, facilitating the breakdown of existing filaments, and the enhancement of filament growth from newly created barbed ends. It does so in concert with actin interacting protein 1 (Aip1), which serves to accelerate cofilin's activity. While progress has been made in understanding its biochemical functions, the physiologic processes the cofilin/Aip1 complex regulates, particularly in higher organisms, are yet to be determined. We have generated an allelic series for WD40 repeat protein 1 (Wdr1), the mammalian homolog of Aip1, and report that reductions in Wdr1 function …

Computational Identification And Functional Validation Of Regulatory Motifs In Cartilage-Expressed Genes, Sherri R Davies, Li-Wei Chang, Debabrata Patra, Xiaoyun Xing, Karen Posey, Jacqueline Hecht, Gary D Stormo, Linda J Sandell

Journal Articles

Chondrocyte gene regulation is important for the generation and maintenance of cartilage tissues. Several regulatory factors have been identified that play a role in chondrogenesis, including the positive transacting factors of the SOX family such as SOX9, SOX5, and SOX6, as well as negative transacting factors such as C/EBP and delta EF1. However, a complete understanding of the intricate regulatory network that governs the tissue-specific expression of cartilage genes is not yet available. We have taken a computational approach to identify cis-regulatory, transcription factor (TF) binding motifs in a set of cartilage characteristic genes to better define the transcriptional regulatory …

Neural Reprogramming In Retinal Degeneration, Robert E Marc, Bryan W Jones, James R Anderson, Krista Kinard, David W Marshak, John H Wilson, Theodore Wensel, Robert J Lucas

Journal Articles

PURPOSE: Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. The authors sought to explore the functional expression of ionotropic (iGluR) and group 3, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degeneration.

METHODS: Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degeneration and a sample of human RP.

RESULTS: After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, whereas amacrine and ganglion …

Quantitative Diffusion Tensor Imaging Detects Dopaminergic Neuronal Degeneration In A Murine Model Of Parkinson's Disease, Michael D Boska, Khader M Hasan, Danette Kibuule, Rebecca Banerjee, Erin Mcintyre, Jay A Nelson, Theresa Hahn, Howard E Gendelman, R Lee Mosley

Journal Articles

Early diagnosis of Parkinson's disease (PD) is required to improve therapeutic responses. Indeed, a clinical diagnosis of resting tremor, rigidity, movement and postural deficiencies usually reflect >50% loss of the nigrostriatal system in disease. In a step to address this, quantitative diffusion tensor magnetic resonance imaging (DTI) was used to assess nigrostriatal degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication model of dopaminergic nigral degeneration. We now demonstrate increased average diffusion (p

Importance Of The Ebp (Endocarditis- And Biofilm-Associated Pilus) Locus In The Pathogenesis Of Enterococcus Faecalis Ascending Urinary Tract Infection, Kavindra V Singh, Sreedhar R Nallapareddy, Barbara E Murray

Journal Articles

BACKGROUND: We recently demonstrated that the ubiquitous Enterococcus faecalis ebp (endocarditis- and biofilm-associated pilus) operon is important for biofilm formation and experimental endocarditis. Here, we assess its role in murine urinary tract infection (UTI) by use of wild-type E. faecalis OG1RF and its nonpiliated, ebpA allelic replacement mutant (TX5475).

METHODS: OG1RF and TX5475 were administered transurethrally either at an ~1 : 1 ratio (competition assay) or individually (monoinfection). Kidney pairs and urinary bladders were cultured 48 h after infection. These strains were also tested in a peritonitis model.

RESULTS: No differences were observed in the peritonitis model. In mixed UTIs, …

Single-Stranded Dna-Binding Proteins Regulate The Abundance Of Lim Domain And Lim Domain-Binding Proteins., Zhixiong Xu, Xianzhang Meng, Ying Cai, Hong Liang, Lalitha Nagarajan, Stephen J Brandt

Journal Articles

The LIM domain-binding protein Ldb1 is an essential cofactor of LIM-homeodomain (LIM-HD) and LIM-only (LMO) proteins in development. The stoichiometry of Ldb1, LIM-HD, and LMO proteins is tightly controlled in the cell and is likely a critical determinant of their biological actions. Single-stranded DNA-binding proteins (SSBPs) were recently shown to interact with Ldb1 and are also important in developmental programs. We establish here that two mammalian SSBPs, SSBP2 and SSBP3, contribute to an erythroid DNA-binding complex that contains the transcription factors Tal1 and GATA-1, the LIM domain protein Lmo2, and Ldb1 and binds a bipartite E-box-GATA DNA sequence motif. In …

Aldosterone-Induced Sgk1 Relieves Dot1a-Af9-Mediated Transcriptional Repression Of Epithelial Na+ Channel Alpha, Wenzheng Zhang, Xuefeng Xia, Mary Rose Reisenauer, Timo Rieg, Florian Lang, Dietmar Kuhl, Volker Vallon, Bruce C Kone

Journal Articles

Aldosterone plays a major role in the regulation of salt balance and the pathophysiology of cardiovascular and renal diseases. Many aldosterone-regulated genes--including that encoding the epithelial Na+ channel (ENaC), a key arbiter of Na+ transport in the kidney and other epithelia--have been identified, but the mechanisms by which the hormone modifies chromatin structure and thus transcription remain unknown. We previously described the basal repression of ENaCalpha by a complex containing the histone H3 Lys79 methyltransferase disruptor of telomeric silencing alternative splice variant a (Dot1a) and the putative transcription factor ALL1-fused gene from chromosome 9 (Af9) as well as the release …