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Full-Text Articles in Life Sciences
Biological Significance Of Photoreceptor Photocycle Length: Vivid Photocycle Governs The Dynamic Vivid-White Collar Complex Pool Mediating Photo-Adaptation And Response To Changes In Light Intensity, Arko Dasgupta, Chen-Hui Chen, Changhwan Lee, Amy S. Gladfelter, Jay C. Dunlap, Jennifer J. Loros
Biological Significance Of Photoreceptor Photocycle Length: Vivid Photocycle Governs The Dynamic Vivid-White Collar Complex Pool Mediating Photo-Adaptation And Response To Changes In Light Intensity, Arko Dasgupta, Chen-Hui Chen, Changhwan Lee, Amy S. Gladfelter, Jay C. Dunlap, Jennifer J. Loros
Dartmouth Scholarship
Most organisms on earth sense light through the use of chromophore-bearing photoreceptive proteins with distinct and characteristic photocycle lengths, yet the biological significance of this adduct decay length is neither understood nor has been tested. In the filamentous fungus Neurospora crassa VIVID (VVD) is a critical player in the process of photoadaptation, the attenuation of light-induced responses and the ability to maintain photosensitivity in response to changing light intensities. Detailed in vitro analysis of the photochemistry of the blue light sensing, FAD binding, LOV domain of VVD has revealed residues around the site of photo-adduct formation that influence the stability …
Identification Of Cell Cycle–Regulated Genes Periodically Expressed In U2os Cells And Their Regulation By Foxm1 And E2f Transcription Factors, Gavin D. Grant, Lionel Brooks Iii, Xiaoyang Zhang, J. Matthew Mahoney, Viktor Martyanov, Tammara A. Wood, Gavin Sherlock, Chao Cheng, Michael L. Whitfield
Identification Of Cell Cycle–Regulated Genes Periodically Expressed In U2os Cells And Their Regulation By Foxm1 And E2f Transcription Factors, Gavin D. Grant, Lionel Brooks Iii, Xiaoyang Zhang, J. Matthew Mahoney, Viktor Martyanov, Tammara A. Wood, Gavin Sherlock, Chao Cheng, Michael L. Whitfield
Dartmouth Scholarship
We identify the cell cycle–regulated mRNA transcripts genome-wide in the osteosarcoma-derived U2OS cell line. This results in 2140 transcripts mapping to 1871 unique cell cycle–regulated genes that show periodic oscillations across multiple synchronous cell cycles. We identify genomic loci bound by the G2/M transcription factor FOXM1 by chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) and associate these with cell cycle–regulated genes. FOXM1 is bound to cell cycle–regulated genes with peak expression in both S phase and G2/M phases. We show that ChIP-seq genomic loci are responsive to FOXM1 using a real-time luciferase assay in live cells, showing that FOXM1 strongly …
Insights Into Mrnp Biogenesis Provided By New Genetic Interactions Among Export And Transcription Factors, Francisco Estruch, Christine Hodge, Natalia Gómez-Navarro, Lorena Peiró-Chova, Catherine V. Heath, Charles N. Cole
Insights Into Mrnp Biogenesis Provided By New Genetic Interactions Among Export And Transcription Factors, Francisco Estruch, Christine Hodge, Natalia Gómez-Navarro, Lorena Peiró-Chova, Catherine V. Heath, Charles N. Cole
Dartmouth Scholarship
The various steps of mRNP biogenesis (transcription, processing and export) are interconnected. It has been shown that the transcription machinery plays a pivotal role in mRNP assembly, since several mRNA export factors are recruited during transcription and physically interact with components of the transcription machinery. Although the shuttling DEAD-box protein Dbp5p is concentrated on the cytoplasmic fibrils of the NPC, previous studies demonstrated that it interacts physically and genetically with factors involved in transcription initiation. We investigated the effect of mutations affecting various components of the transcription initiation apparatus on the phenotypes of mRNA export mutant strains. Our results show …
Auf1/Hnrnp D Represses Expression Of Vegf In Macrophages, Abigail Fellows, Mary E. Griffin, Brenda L. Petrella, Lihui Zhong, Fatemeh P. Parvin-Nejad, Roy Fava, Peter Morganelli, R. Brooks Robey, Ralph C. Nichols
Auf1/Hnrnp D Represses Expression Of Vegf In Macrophages, Abigail Fellows, Mary E. Griffin, Brenda L. Petrella, Lihui Zhong, Fatemeh P. Parvin-Nejad, Roy Fava, Peter Morganelli, R. Brooks Robey, Ralph C. Nichols
Dartmouth Scholarship
Vascular endothelial growth factor (VEGF) is a regulator of vascularization in development and is a key growth factor in tissue repair. In disease, VEGF contributes to vascularization of solid tumors and arthritic joints. This study examines the role of the mRNA-binding protein AUF1/heterogeneous nuclear ribonucleoprotein D (AUF1) in VEGF gene expression. We show that overexpression of AUF1 in mouse macrophage-like RAW-264.7 cells suppresses endogenous VEGF protein levels. To study 3′ untranslated region (UTR)–mediated regulation, we introduced the 3′ UTR of VEGF mRNA into a luciferase reporter gene. Coexpression of AUF1 represses VEGF-3′ UTR reporter expression in RAW-264.7 cells and in …
Genetic And Molecular Characterization Of A Cryptochrome From The Filamentous Fungus Neurospora Crassa, Allan C. Froehlich, Chen-Hui Chen, William J. Belden, Cornelia Madeti
Genetic And Molecular Characterization Of A Cryptochrome From The Filamentous Fungus Neurospora Crassa, Allan C. Froehlich, Chen-Hui Chen, William J. Belden, Cornelia Madeti
Dartmouth Scholarship
In plants and animals, cryptochromes function as either photoreceptors or circadian clock components. We have examined the cryptochrome from the filamentous fungus Neurospora crassa and demonstrate that Neurospora cry encodes a DASH-type cryptochrome that appears capable of binding flavin adenine dinucleotide (FAD) and methenyltetrahydrofolate (MTHF). The cry transcript and CRY protein levels are strongly induced by blue light in a wc-1-dependent manner, and cry transcript is circadianly regulated, with a peak abundance opposite in phase to frq. Neither deletion nor overexpression of cry appears to perturb the free-running circadian clock. However, cry disruption knockout mutants show a small phase delay …
Rpb4p, A Subunit Of Rna Polymerase Ii, Mediates Mrna Export During Stress, Marganit Farago, Tal Nahari, Christopher Hammel, Charles N. Cole, Mordechai Choder
Rpb4p, A Subunit Of Rna Polymerase Ii, Mediates Mrna Export During Stress, Marganit Farago, Tal Nahari, Christopher Hammel, Charles N. Cole, Mordechai Choder
Dartmouth Scholarship
Changes in gene expression represent a major mechanism by which cells respond to stress. We and other investigators have previously shown that the yeast RNA polymerase II subunit Rpb4p is required for transcription under various stress conditions, but not under optimal growth conditions. Here we show that, in addition to its role in transcription, Rpb4p is also required for mRNA export, but only when cells are exposed to stress conditions. The roles of Rpb4p in transcription and in mRNA export can be uncoupled genetically by specific mutations in Rpb4p. Both functions of Rpb4p are required to maintain cell viability during …
Cloning Of Human Acetyl-Coa Carboxylase-Beta And Its Unique Features., Joohun Ha, Jung-Kee Lee, Kyung-Sup Kim, Lee A. Witters, Ki-Han Kim
Cloning Of Human Acetyl-Coa Carboxylase-Beta And Its Unique Features., Joohun Ha, Jung-Kee Lee, Kyung-Sup Kim, Lee A. Witters, Ki-Han Kim
Dartmouth Scholarship
Acetyl-CoA carboxylase, which has a molecular mass of 265 kDa (ACC-alpha), catalyzes the rate-limiting step in the biosynthesis of long-chain fatty acids. In this study we report the complete amino acid sequence and unique features of an isoform of ACC with a molecular mass of 275 kDa (ACC-beta), which is primarily expressed in heart and skeletal muscles. In these tissues, ACC-beta may be involved in the regulation of fatty acid oxidation, rather than fatty acid biosynthesis. ACC-beta contains an amino acid sequence at the N terminus which is about 200 amino acids long and may be uniquely related to the …
A Novel Iron-Regulated Metal Transporter From Plants Identified By Functional Expression In Yeast., David Eide, Margaret Broderius, Jeanette Fett, Mary Lou Guerinot
A Novel Iron-Regulated Metal Transporter From Plants Identified By Functional Expression In Yeast., David Eide, Margaret Broderius, Jeanette Fett, Mary Lou Guerinot
Dartmouth Scholarship
Iron is an essential nutrient for virtually all organisms. The IRT1 (iron-regulated transporter) gene of the plant Arabidopsis thaliana, encoding a probable Fe(II) transporter, was cloned by functional expression in a yeast strain defective for iron uptake. Yeast expressing IRT1 possess a novel Fe(II) uptake activity that is strongly inhibited by Cd. IRT1 is predicted to be an integral membrane protein with a metal-binding domain. Data base comparisons and Southern blot analysis indicated that IRT1 is a member of a gene family in Arabidopsis. Related sequences were also found in the genomes of rice, yeast, nematodes, and humans. In Arabidopsis, …
Circadian Clock Locus Frequency: Protein Encoded By A Single Open Reading Frame Defines Period Length And Temperature Compensation., Benjamin D. Aronson, Keith A. Johnson, Jay C. Dunlap
Circadian Clock Locus Frequency: Protein Encoded By A Single Open Reading Frame Defines Period Length And Temperature Compensation., Benjamin D. Aronson, Keith A. Johnson, Jay C. Dunlap
Dartmouth Scholarship
The frequency (frq) locus encodes a key component, a state variable, in a cellular oscillator generating circadian rhythmicity. Two transcripts have been mapped to this region, and data presented here are consistent with the existence of a third transcript. Analysis of cDNA clones and clock mutants from this region focuses attention on one transcript encoding a protein. FRQ, which is a central clock component: (i) mutations in all of the semidominant frq alleles are the result of single amino acid substitutions and map to the open reading frame (ORF) encoding FRQ; (ii) deletion of this ORF, or a frameshift mutation …