Medicine and Health Sciences Commons^™

Genes Adopt Non-Optimal Codon Usage To Generate Cell Cycle-Dependent Oscillations In Protein Levels., Milana Frenkel-Morgenstern, Tamar Danon, Thomas Christian, Takao Igarashi, Lydia Cohen, Ya-Ming Hou, Lars Juhl Jensen

Department of Biochemistry and Molecular Biology Faculty Papers

The cell cycle is a temporal program that regulates DNA synthesis and cell division. When we compared the codon usage of cell cycle-regulated genes with that of other genes, we discovered that there is a significant preference for non-optimal codons. Moreover, genes encoding proteins that cycle at the protein level exhibit non-optimal codon preferences. Remarkably, cell cycle-regulated genes expressed in different phases display different codon preferences. Here, we show empirically that transfer RNA (tRNA) expression is indeed highest in the G2 phase of the cell cycle, consistent with the non-optimal codon usage of genes expressed at this time, and lowest …

Mitochondrial Genome Sequence Analysis: A Custom Bioinformatics Pipeline Substantially Improves Affymetrix Mitochip V2.0 Call Rate And Accuracy., Hongbo M Xie, Juan C Perin, Theodore G Schurr, Matthew C Dulik, Sergey I Zhadanov, Joseph A Baur, Michael P King, Emily Place, Colleen Clarke, Michael Grauer, Jonathan Schug, Avni Santani, Anthony Albano, Cecilia Kim, Vincent Procaccio, Hakon Hakonarson, Xiaowu Gai, Marni J Falk

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: Mitochondrial genome sequence analysis is critical to the diagnostic evaluation of mitochondrial disease. Existing methodologies differ widely in throughput, complexity, cost efficiency, and sensitivity of heteroplasmy detection. Affymetrix MitoChip v2.0, which uses a sequencing-by-genotyping technology, allows potentially accurate and high-throughput sequencing of the entire human mitochondrial genome to be completed in a cost-effective fashion. However, the relatively low call rate achieved using existing software tools has limited the wide adoption of this platform for either clinical or research applications. Here, we report the design and development of a custom bioinformatics software pipeline that achieves a much improved call rate …

Potential For Interdependent Development Of Trna Determinants For Aminoacylation And Ribosome Decoding., Cuiping Liu, Howard Gamper, Hanqing Liu, Barry S Cooperman, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Although the nucleotides in tRNA required for aminoacylation are conserved in evolution, bacterial aminoacyl-transfer RNA synthetases are unable to acylate eukaryotic tRNA. The cross-species barrier may be due to the absence of eukaryote-specific domains from bacterial aminoacyl-transfer RNA synthetases. Here we show that whereas Escherichia coli CysRS cannot acylate human tRNA(Cys), the fusion of a eukaryote-specific domain of human CysRS overcomes the cross-species barrier in human tRNA(Cys). In addition to enabling recognition of the sequence differences in the tertiary core of tRNA(Cys), the fused eukaryotic domain redirects the specificity of E. coli CysRS from the A37 present in bacterial tRNA(Cys) …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Asymmetric Deactivation Of Hiv-1 Gp41 Following Fusion Inhibitor Binding., Kristen M Kahle, H Kirby Steger, Michael J Root

Department of Biochemistry and Molecular Biology Faculty Papers

Both equilibrium and nonequilibrium factors influence the efficacy of pharmaceutical agents that target intermediate states of biochemical reactions. We explored the intermediate state inhibition of gp41, part of the HIV-1 envelope glycoprotein complex (Env) that promotes viral entry through membrane fusion. This process involves a series of gp41 conformational changes coordinated by Env interactions with cellular CD4 and a chemokine receptor. In a kinetic window between CD4 binding and membrane fusion, the N- and C-terminal regions of the gp41 ectodomain become transiently susceptible to inhibitors that disrupt Env structural transitions. In this study, we sought to identify kinetic parameters that …

Interaction With Lc8 Is Required For Pak1 Nuclear Import And Is Indispensable For Zebrafish Development., Christine M Lightcap, Gabor Kari, Luis E Arias-Romero, Jonathan Chernoff, Ulrich Rodeck, John C Williams

Department of Biochemistry and Molecular Biology Faculty Papers

Pak1 (p21 activated kinase 1) is a serine/threonine kinase implicated in regulation of cell motility and survival and in malignant transformation of mammary epithelial cells. In addition, the dynein light chain, LC8, has been described to cooperate with Pak1 in malignant transformation of breast cancer cells. Pak1 itself may aid breast cancer development by phosphorylating nuclear proteins, including estrogen receptor alpha. Recently, we showed that the LC8 binding site on Pak1 is adjacent to the nuclear localization sequence (NLS) required for Pak1 nuclear import. Here, we demonstrate that the LC8-Pak1 interaction is necessary for epidermal growth factor (EGF)-induced nuclear import …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Neutralization Of Botulinum Neurotoxin By A Human Monoclonal Antibody Specific For The Catalytic Light Chain., Sharad P Adekar, Tsuyoshi Takahashi, R Mark Jones, Fetweh H Al-Saleem, Denise M Ancharski, Michael J Root, B P Kapadnis, Lance L Simpson, Scott K Dessain

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: Botulinum neurotoxins (BoNT) are a family of category A select bioterror agents and the most potent biological toxins known. Cloned antibody therapeutics hold considerable promise as BoNT therapeutics, but the therapeutic utility of antibodies that bind the BoNT light chain domain (LC), a metalloprotease that functions in the cytosol of cholinergic neurons, has not been thoroughly explored.

METHODS AND FINDINGS: We used an optimized hybridoma method to clone a fully human antibody specific for the LC of serotype A BoNT (BoNT/A). The 4LCA antibody demonstrated potent in vivo neutralization when administered alone and collaborated with an antibody specific for …

Abeta42 Mutants With Different Aggregation Profiles Induce Distinct Pathologies In Drosophila., Koichi Iijima, Hsueh-Cheng Chiang, Stephen A Hearn, Inessa Hakker, Anthony Gatt, Christopher Shenton, Linda Granger, Amy Leung, Kanae Iijima-Ando, Yi Zhong

Department of Biochemistry and Molecular Biology Faculty Papers

Aggregation of the amyloid-beta-42 (Abeta42) peptide in the brain parenchyma is a pathological hallmark of Alzheimer's disease (AD), and the prevention of Abeta aggregation has been proposed as a therapeutic intervention in AD. However, recent reports indicate that Abeta can form several different prefibrillar and fibrillar aggregates and that each aggregate may confer different pathogenic effects, suggesting that manipulation of Abeta42 aggregation may not only quantitatively but also qualitatively modify brain pathology. Here, we compare the pathogenicity of human Abeta42 mutants with differing tendencies to aggregate. We examined the aggregation-prone, EOFAD-related Arctic mutation (Abeta42Arc) and an artificial mutation (Abeta42art) that …

Anti-Human Immunodeficiency Virus (Hiv) Activities Of Halogenated Gomisin J Derivatives, New Nonnucleoside Inhibitors Of Hiv Type 1 Reverse Transcriptase, Toshiaki Fujihashi, Hiroto Hara, Toshiya Sakata, Kazuya Mori, Hirotaka Higuchi, Akio Tanaka, Hideko Kaji, Akira Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

Halogenated gomisin J (a derivative of lignan compound), represented by the bromine derivative 1506 [(6R, 7S, S-biar)-4,9-dibromo-3,10-dihydroxy-1,2,11,12-tetramethoxy-6, 7-dimethyl-5,6,7,8- tetrahydrodibenzo[a,c]cyclo-octene], was found to be a potent inhibitor of the cytopathic effects of human immunodeficiency virus type 1 (HIV-1) on MT-4 human T cells (50% effective dose, 0.1 to 0.5 microM). Gomisin J derivatives were active in preventing p24 production from acutely HIV-1-infected H9 cells. The selective indices (toxic dose/effective dose) of these compounds were as high as > 300 in some systems. 1506 was active against 3'-azido-3'-deoxythymidine-resistant HIV-1 and acted synergistically with AZT and 2',3'-ddC. 1506 inhibited HIV-1 reverse transcriptase (RT) in …

Sequencing Of Cdna From 50 Unrelated Patients Reveals That Mutations In The Triple-Helical Domain Of Type Iii Procollagen Are An Infrequent Cause Of Aortic Aneurysms., Gerard Tromp, Yuli Wu, Darwin J. Prockop, Swarna L. Madhatheri, Caren Kleinert, James J. Earley, Jiapiao Zhuang, Orjan Norrgård, R. Clement Darling, William M. Abbott, C. William Cole, Pekka Jaakkola, Markku Ryynanen, William H. Pearce, James S.T. Yao, Kari Majamaa, Stanton N. Smullens, Zoran Gatalica, Robert E. Ferrell, Sergio A. Jimenez, Charles E. Jackson, Virginia V. Michels, Michael Kaye, Helena Kuivaniemi

Department of Biochemistry and Molecular Biology Faculty Papers

Detailed DNA sequencing of the triple-helical domain of type III procollagen was carried out on cDNA prepared from 54 patients with aortic aneurysms. The 43 male and 11 female patients originated from 50 different families and five different nationalities. 43 patients had at least one additional blood relative who had aneurysms. Five overlapping asymmetric PCR products, covering all the coding sequences of the triple-helical domain of type III procollagen, were sequenced with 28 specific sequencing primers. Analysis of the sequencing gels revealed only two nucleotide changes that altered the structure of the protein. One was a substitution of threonine for …