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Articles 91 - 120 of 155
Full-Text Articles in Medical Biochemistry
Structural And Functional Analysis Of A Β2-Adrenergic Receptor Complex With Grk5., Konstantin E. Komolov, Yang Du, Nguyen Minh Duc, Robin M. Betz, João P.G.L.M. Rodrigues, Ryan D. Leib, Dhabaleswar Patra, Georgios Skiniotis, Christopher M. Adams, Ron O. Dror, Ka Young Chung, Brian K. Kobilka, Jeffrey L. Benovic
Structural And Functional Analysis Of A Β2-Adrenergic Receptor Complex With Grk5., Konstantin E. Komolov, Yang Du, Nguyen Minh Duc, Robin M. Betz, João P.G.L.M. Rodrigues, Ryan D. Leib, Dhabaleswar Patra, Georgios Skiniotis, Christopher M. Adams, Ron O. Dror, Ka Young Chung, Brian K. Kobilka, Jeffrey L. Benovic
Department of Biochemistry and Molecular Biology Faculty Papers
The phosphorylation of agonist-occupied G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) functions to turn off G-protein signaling and turn on arrestin-mediated signaling. While a structural understanding of GPCR/G-protein and GPCR/arrestin complexes has emerged in recent years, the molecular architecture of a GPCR/GRK complex remains poorly defined. We used a comprehensive integrated approach of cross-linking, hydrogen-deuterium exchange mass spectrometry (MS), electron microscopy, mutagenesis, molecular dynamics simulations, and computational docking to analyze GRK5 interaction with the β2-adrenergic receptor (β2AR). These studies revealed a dynamic mechanism of complex formation that involves large conformational changes in the GRK5 RH/catalytic domain interface upon receptor binding. …
G Protein-Coupled Receptor Kinase-2 (Grk-2) Regulates Serotonin Metabolism Through The Monoamine Oxidase Amx-2 In Caenorhabditis Elegans., Jianjun Wang, Jiansong Luo, Dipendra K. Aryal, William C. Wetsel, Richard Nass, Jeffrey L. Benovic
G Protein-Coupled Receptor Kinase-2 (Grk-2) Regulates Serotonin Metabolism Through The Monoamine Oxidase Amx-2 In Caenorhabditis Elegans., Jianjun Wang, Jiansong Luo, Dipendra K. Aryal, William C. Wetsel, Richard Nass, Jeffrey L. Benovic
Department of Biochemistry and Molecular Biology Faculty Papers
G protein-coupled receptors (GPCRs) regulate many animal behaviors. GPCR signaling is mediated by agonist-promoted interactions of GPCRs with heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. To further elucidate the role of GRKs in regulating GPCR-mediated behaviors, we utilized the genetic model system Caenorhabditis elegans Our studies demonstrate that grk-2 loss-of-function strains are egg laying-defective and contain low levels of serotonin (5-HT) and high levels of the 5-HT metabolite 5-hydroxyindole acetic acid (5-HIAA). The egg laying defect could be rescued by the expression of wild type but not by catalytically inactive grk-2 or by the selective expression of grk-2 in …
Cool-Associated Tyrosine-Phosphorylated Protein 1 Is Required For The Anchorage-Independent Growth Of Cervical Carcinoma Cells By Binding Paxillin And Promoting Akt Activation., Sungsoo M. Yoo, Arash Latifkar, Richard A. Cerione, Marc A. Antonyak
Cool-Associated Tyrosine-Phosphorylated Protein 1 Is Required For The Anchorage-Independent Growth Of Cervical Carcinoma Cells By Binding Paxillin And Promoting Akt Activation., Sungsoo M. Yoo, Arash Latifkar, Richard A. Cerione, Marc A. Antonyak
Department of Biochemistry and Molecular Biology Faculty Papers
Cool-associated tyrosine-phosphorylated protein 1 (Cat-1) is a signaling scaffold as well as an ADP-ribosylation factor-GTPase-activating protein. Although best known for its role in cell migration, we recently showed that the ability of Cat-1 to bind paxillin, a major constituent of focal complexes, is also essential for the anchorage-independent growth of HeLa cervical carcinoma cells. Here we set out to learn more about the underlying mechanism by which Cat-paxillin interactions mediate this effect. We show that knocking down paxillin expression in HeLa cells promotes their ability to form colonies in soft agar, whereas ectopically expressing paxillin in these cells inhibits this …
Portal Protein Functions Akin To A Dna-Sensor That Couples Genome-Packaging To Icosahedral Capsid Maturation., Ravi K. Lokareddy, Rajeshwer S. Sankhala, Ankoor Roy, Pavel V. Afonine, Tina Motwani, Carolyn M M. Teschke, Kristin N. Parent, Gino Cingolani
Portal Protein Functions Akin To A Dna-Sensor That Couples Genome-Packaging To Icosahedral Capsid Maturation., Ravi K. Lokareddy, Rajeshwer S. Sankhala, Ankoor Roy, Pavel V. Afonine, Tina Motwani, Carolyn M M. Teschke, Kristin N. Parent, Gino Cingolani
Department of Biochemistry and Molecular Biology Faculty Papers
Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity …
Cleavage Of Dfna5 By Caspase-3 During Apoptosis Mediates Progression To Secondary Necrotic/Pyroptotic Cell Death., Corey Rogers, Teresa Fernandes-Alnemri, Lindsey Mayes, Diana Alnemri, Gino Cingolani, Emad S. Alnemri
Cleavage Of Dfna5 By Caspase-3 During Apoptosis Mediates Progression To Secondary Necrotic/Pyroptotic Cell Death., Corey Rogers, Teresa Fernandes-Alnemri, Lindsey Mayes, Diana Alnemri, Gino Cingolani, Emad S. Alnemri
Department of Biochemistry and Molecular Biology Faculty Papers
Apoptosis is a genetically regulated cell suicide programme mediated by activation of the effector caspases 3, 6 and 7. If apoptotic cells are not scavenged, they progress to a lytic and inflammatory phase called secondary necrosis. The mechanism by which this occurs is unknown. Here we show that caspase-3 cleaves the GSDMD-related protein DFNA5 after Asp270 to generate a necrotic DFNA5-N fragment that targets the plasma membrane to induce secondary necrosis/pyroptosis. Cells that express DFNA5 progress to secondary necrosis, when stimulated with apoptotic triggers such as etoposide or vesicular stomatitis virus infection, but disassemble into small apoptotic bodies when DFNA5 …
The Yersinia Pestis Effector Yopm Inhibits Pyrin Inflammasome Activation., Dmitry Ratner, M Pontus A Orning, Megan K. Proulx, Donghai Wang, Mikhail A. Gavrilin, Mark D. Wewers, Emad S. Alnemri, Peter F. Johnson, Bettina Lee, Joan Mecsas, Nobuhiko Kayagaki, Jon D. Goguen, Egil Lien
The Yersinia Pestis Effector Yopm Inhibits Pyrin Inflammasome Activation., Dmitry Ratner, M Pontus A Orning, Megan K. Proulx, Donghai Wang, Mikhail A. Gavrilin, Mark D. Wewers, Emad S. Alnemri, Peter F. Johnson, Bettina Lee, Joan Mecsas, Nobuhiko Kayagaki, Jon D. Goguen, Egil Lien
Department of Biochemistry and Molecular Biology Faculty Papers
Type III secretion systems (T3SS) are central virulence factors for many pathogenic Gram-negative bacteria, and secreted T3SS effectors can block key aspects of host cell signaling. To counter this, innate immune responses can also sense some T3SS components to initiate anti-bacterial mechanisms. The Yersinia pestis T3SS is particularly effective and sophisticated in manipulating the production of pro-inflammatory cytokines IL-1β and IL-18, which are typically processed into their mature forms by active caspase-1 following inflammasome formation. Some effectors, like Y. pestis YopM, may block inflammasome activation. Here we show that YopM prevents Y. pestis induced activation of the Pyrin inflammasome induced …
The Α-Arrestin Arrdc3 Regulates The Endosomal Residence Time And Intracellular Signaling Of The Β2-Adrenergic Receptor., Xufan Tian, Roshanak Irannejad, Shanna L. Bowman, Yang Du, Manojkumar A. Puthenveedu, Mark Von Zastrow, Jeffrey L. Benovic
The Α-Arrestin Arrdc3 Regulates The Endosomal Residence Time And Intracellular Signaling Of The Β2-Adrenergic Receptor., Xufan Tian, Roshanak Irannejad, Shanna L. Bowman, Yang Du, Manojkumar A. Puthenveedu, Mark Von Zastrow, Jeffrey L. Benovic
Department of Biochemistry and Molecular Biology Faculty Papers
Arrestin domain-containing protein 3 (ARRDC3) is a member of the mammalian α-arrestin family, which is predicted to share similar tertiary structure with visual-/β-arrestins and also contains C-terminal PPXY motifs that mediate interaction with E3 ubiquitin ligases. Recently, ARRDC3 has been proposed to play a role in regulating the trafficking of G protein-coupled receptors, although mechanistic insight into this process is lacking. Here, we focused on characterizing the role of ARRDC3 in regulating the trafficking of the β2-adrenergic receptor (β2AR). We find that ARRDC3 primarily localizes to EEA1-positive early endosomes and directly interacts with the β2AR in a ligand-independent manner. Although …
Molecular Basis And Consequences Of The Cytochrome C-Trna Interaction., Cuiping Liu, Aaron J Stonestrom, Thomas Christian, Jeongsik Yong, Ryuichi Takase, Ya-Ming Hou, Xiaolu Yang
Molecular Basis And Consequences Of The Cytochrome C-Trna Interaction., Cuiping Liu, Aaron J Stonestrom, Thomas Christian, Jeongsik Yong, Ryuichi Takase, Ya-Ming Hou, Xiaolu Yang
Department of Biochemistry and Molecular Biology Faculty Papers
The intrinsic apoptosis pathway occurs through the release of mitochondrial cytochrome c to the cytosol, where it promotes activation of the caspase family of proteases. The observation that tRNA binds to cytochrome c revealed a previously unexpected mode of apoptotic regulation. However, the molecular characteristics of this interaction, and its impact on each interaction partner, are not well understood. Using a novel fluorescence assay, we show here that cytochrome c binds to tRNA with an affinity comparable with other tRNA-protein binding interactions and with a molecular ratio of ∼3:1. Cytochrome c recognizes the tertiary structural features of tRNA, particularly in …
A Parp1-Erk2 Synergism Is Required For The Induction Of Ltp., L Visochek, G Grigoryan, A Kalal, H Milshtein-Parush, N Gazit, I Slutsky, A Yeheskel, A Shainberg, A Castiel, R Seger, Marie-France Langelier, F Dantzer, Pascal Jabbour Md, M Segal, M Cohen-Armon
A Parp1-Erk2 Synergism Is Required For The Induction Of Ltp., L Visochek, G Grigoryan, A Kalal, H Milshtein-Parush, N Gazit, I Slutsky, A Yeheskel, A Shainberg, A Castiel, R Seger, Marie-France Langelier, F Dantzer, Pascal Jabbour Md, M Segal, M Cohen-Armon
Department of Biochemistry and Molecular Biology Faculty Papers
Unexpectedly, a post-translational modification of DNA-binding proteins, initiating the cell response to single-strand DNA damage, was also required for long-term memory acquisition in a variety of learning paradigms. Our findings disclose a molecular mechanism based on PARP1-Erk synergism, which may underlie this phenomenon. A stimulation induced PARP1 binding to phosphorylated Erk2 in the chromatin of cerebral neurons caused Erk-induced PARP1 activation, rendering transcription factors and promoters of immediate early genes (IEG) accessible to PARP1-bound phosphorylated Erk2. Thus, Erk-induced PARP1 activation mediated IEG expression implicated in long-term memory. PARP1 inhibition, silencing, or genetic deletion abrogated stimulation-induced Erk-recruitment to IEG promoters, gene …
The Eff-1a Cytoplasmic Domain Influences Hypodermal Cell Fusions In C. Elegans But Is Not Dependent On 14-3-3 Proteins., Jessica H Shinn-Thomas, Jacob J Del Campo, Jianjun Wang, William A Mohler
The Eff-1a Cytoplasmic Domain Influences Hypodermal Cell Fusions In C. Elegans But Is Not Dependent On 14-3-3 Proteins., Jessica H Shinn-Thomas, Jacob J Del Campo, Jianjun Wang, William A Mohler
Department of Biochemistry and Molecular Biology Faculty Papers
BACKGROUND: Regulatory and biophysical mechanisms of cell-cell fusion are largely unknown despite the fundamental requirement for fused cells in eukaryotic development. Only two cellular fusogens that are not of clear recent viral origin have been identified to date, both in nematodes. One of these, EFF-1, is necessary for most cell fusions in Caenorhabditis elegans. Unregulated EFF-1 expression causes lethality due to ectopic fusion between cells not developmentally programmed to fuse, highlighting the necessity of tight fusogen regulation for proper development. Identifying factors that regulate EFF-1 and its paralog AFF-1 could lead to discovery of molecular mechanisms that control cell fusion …
Autophosphorylation Of The Smk1 Mapk Is Spatially And Temporally Regulated By Ssp2 During Meiotic Development In Yeast., Chong Wai Tio, Gregory Omerza, Sham Sunder, Edward Winter
Autophosphorylation Of The Smk1 Mapk Is Spatially And Temporally Regulated By Ssp2 During Meiotic Development In Yeast., Chong Wai Tio, Gregory Omerza, Sham Sunder, Edward Winter
Department of Biochemistry and Molecular Biology Faculty Papers
Smk1 is a meiosis-specific MAPK that controls spore wall morphogenesis in Saccharomyces cerevisiae. Although Smk1 is activated by phosphorylation of the threonine (T) and tyrosine (Y) in its activation loop, it is not phosphorylated by a dual-specificity MAPK kinase. Instead, the T is phosphorylated by the cyclin-dependent kinase (CDK)-activating kinase, Cak1. The Y is autophosphorylated in an intramolecular reaction that requires a meiosis-specific protein named Ssp2. The meiosis-specific CDK-like kinase, Ime2, was previously shown to positively regulate Smk1. Here we show that Ime2 activity is required to induce the translation of SSP2 mRNA at anaphase II. Ssp2 protein is then …
Atomic Structure Of Grk5 Reveals Distinct Structural Features Novel For G Protein-Coupled Receptor Kinases, Konstantin E. Komolov, Anshul Bhardwaj, Jeffrey L. Benovic
Atomic Structure Of Grk5 Reveals Distinct Structural Features Novel For G Protein-Coupled Receptor Kinases, Konstantin E. Komolov, Anshul Bhardwaj, Jeffrey L. Benovic
Department of Biochemistry and Molecular Biology Faculty Papers
G protein-coupled receptor kinases (GRKs) are members of the protein kinase A, G, and C families (AGC) and play a central role in mediating G protein-coupled receptor phosphorylation and desensitization. One member of the family, GRK5, has been implicated in several human pathologies, including heart failure, hypertension, cancer, diabetes, and Alzheimer disease. To gain mechanistic insight into GRK5 function, we determined a crystal structure of full-length human GRK5 at 1.8 Å resolution. GRK5 in complex with the ATP analog 5'-adenylyl β,γ-imidodiphosphate or the nucleoside sangivamycin crystallized as a monomer. The C-terminal tail (C-tail) of AGC kinase domains is a highly …
The Rise And Fall Of Poly(Adp-Ribose): An Enzymatic Perspective., John M. Pascal, Tom Ellenberger
The Rise And Fall Of Poly(Adp-Ribose): An Enzymatic Perspective., John M. Pascal, Tom Ellenberger
Department of Biochemistry and Molecular Biology Faculty Papers
Human cells respond to DNA damage with an acute and transient burst in production of poly(ADP-ribose), a posttranslational modification that expedites damage repair and plays a pivotal role in cell fate decisions. Poly(ADP-ribose) polymerases (PARPs) and glycohydrolase (PARG) are the key set of enzymes that orchestrate the rise and fall in cellular levels of poly(ADP-ribose). In this perspective, we focus on recent structural and mechanistic insights into the enzymes involved in poly(ADP-ribose) production and turnover, and we highlight important questions that remain to be answered.
Diversification Of Importin-Α Isoforms In Cellular Trafficking And Disease States., Ruth A. Pumroy, Gino Cingolani
Diversification Of Importin-Α Isoforms In Cellular Trafficking And Disease States., Ruth A. Pumroy, Gino Cingolani
Department of Biochemistry and Molecular Biology Faculty Papers
The human genome encodes seven isoforms of importin α which are grouped into three subfamilies known as α1, α2 and α3. All isoforms share a fundamentally conserved architecture that consists of an N-terminal, autoinhibitory, importin-β-binding (IBB) domain and a C-terminal Arm (Armadillo)-core that associates with nuclear localization signal (NLS) cargoes. Despite striking similarity in amino acid sequence and 3D structure, importin-α isoforms display remarkable substrate specificity in vivo. In the present review, we look at key differences among importin-α isoforms and provide a comprehensive inventory of known viral and cellular cargoes that have been shown to associate preferentially with specific …
Disrupting Sumoylation Enhances Transcriptional Function And Ameliorates Polyglutamine Androgen Receptor-Mediated Disease., Jason P Chua, Satya L Reddy, Zhigang Yu, Elisa Giorgetti, Heather L Montie, Sarmistha Mukherjee, Jake Higgins, Richard C Mceachin, Diane M Robins, Diane E Merry, Jorge A Iñiguez-Lluhí, Andrew P Lieberman
Disrupting Sumoylation Enhances Transcriptional Function And Ameliorates Polyglutamine Androgen Receptor-Mediated Disease., Jason P Chua, Satya L Reddy, Zhigang Yu, Elisa Giorgetti, Heather L Montie, Sarmistha Mukherjee, Jake Higgins, Richard C Mceachin, Diane M Robins, Diane E Merry, Jorge A Iñiguez-Lluhí, Andrew P Lieberman
Department of Biochemistry and Molecular Biology Faculty Papers
Expansion of the polyglutamine (polyQ) tract within the androgen receptor (AR) causes neuromuscular degeneration in individuals with spinobulbar muscular atrophy (SBMA). PolyQ AR has diminished transcriptional function and exhibits ligand-dependent proteotoxicity, features that have both been implicated in SBMA; however, the extent to which altered AR transcriptional function contributes to pathogenesis remains controversial. Here, we sought to dissociate effects of diminished AR function from polyQ-mediated proteotoxicity by enhancing the transcriptional activity of polyQ AR. To accomplish this, we bypassed the inhibitory effect of AR SUMOylation (where SUMO indicates small ubiquitin-like modifier) by mutating conserved lysines in the polyQ AR that …
Exploring The Atomic Structure And Conformational Flexibility Of A 320 Å Long Engineered Viral Fiber Using X-Ray Crystallography., Anshul Bhardwaj, Sherwood R Casjens, Gino Cingolani
Exploring The Atomic Structure And Conformational Flexibility Of A 320 Å Long Engineered Viral Fiber Using X-Ray Crystallography., Anshul Bhardwaj, Sherwood R Casjens, Gino Cingolani
Department of Biochemistry and Molecular Biology Faculty Papers
Protein fibers are widespread in nature, but only a limited number of high-resolution structures have been determined experimentally. Unlike globular proteins, fibers are usually recalcitrant to form three-dimensional crystals, preventing single-crystal X-ray diffraction analysis. In the absence of three-dimensional crystals, X-ray fiber diffraction is a powerful tool to determine the internal symmetry of a fiber, but it rarely yields atomic resolution structural information on complex protein fibers. An 85-residue-long minimal coiled-coil repeat unit (MiCRU) was previously identified in the trimeric helical core of tail needle gp26, a fibrous protein emanating from the tail apparatus of the bacteriophage P22 virion. Here, …
Possible Steps Of Complete Disassembly Of Post-Termination Complex By Yeast Eef3 Deduced From Inhibition By Translocation Inhibitors., Shinya Kurata, Ben Shen, Jun O Liu, Nono Takeuchi, Akira Kaji, Hideko Kaji
Possible Steps Of Complete Disassembly Of Post-Termination Complex By Yeast Eef3 Deduced From Inhibition By Translocation Inhibitors., Shinya Kurata, Ben Shen, Jun O Liu, Nono Takeuchi, Akira Kaji, Hideko Kaji
Department of Biochemistry and Molecular Biology Faculty Papers
Ribosomes, after one round of translation, must be recycled so that the next round of translation can occur. Complete disassembly of post-termination ribosomal complex (PoTC) in yeast for the recycling consists of three reactions: release of tRNA, release of mRNA and splitting of ribosomes, catalyzed by eukaryotic elongation factor 3 (eEF3) and ATP. Here, we show that translocation inhibitors cycloheximide and lactimidomycin inhibited all three reactions. Cycloheximide is a non-competitive inhibitor of both eEF3 and ATP. The inhibition was observed regardless of the way PoTC was prepared with either release factors or puromycin. Paromomycin not only inhibited all three reactions …
The Tip Of The Tail Needle Affects The Rate Of Dna Delivery By Bacteriophage P22., Justin C Leavitt, Lasha Gogokhia, Eddie B Gilcrease, Anshul Bhardwaj, Gino Cingolani, Sherwood R Casjens
The Tip Of The Tail Needle Affects The Rate Of Dna Delivery By Bacteriophage P22., Justin C Leavitt, Lasha Gogokhia, Eddie B Gilcrease, Anshul Bhardwaj, Gino Cingolani, Sherwood R Casjens
Department of Biochemistry and Molecular Biology Faculty Papers
The P22-like bacteriophages have short tails. Their virions bind to their polysaccharide receptors through six trimeric tailspike proteins that surround the tail tip. These short tails also have a trimeric needle protein that extends beyond the tailspikes from the center of the tail tip, in a position that suggests that it should make first contact with the host's outer membrane during the infection process. The base of the needle serves as a plug that keeps the DNA in the virion, but role of the needle during adsorption and DNA injection is not well understood. Among the P22-like phages are needle …
Dynein And Dynactin Leverage Their Bivalent Character To Form A High-Affinity Interaction., Amanda E Siglin, Shangjin Sun, Jeffrey K Moore, Sarah Tan, Martin Poenie, James D Lear, Tatyana Polenova, John A Cooper, John C Williams
Dynein And Dynactin Leverage Their Bivalent Character To Form A High-Affinity Interaction., Amanda E Siglin, Shangjin Sun, Jeffrey K Moore, Sarah Tan, Martin Poenie, James D Lear, Tatyana Polenova, John A Cooper, John C Williams
Department of Biochemistry and Molecular Biology Faculty Papers
Cytoplasmic dynein and dynactin participate in retrograde transport of organelles, checkpoint signaling and cell division. The principal subunits that mediate this interaction are the dynein intermediate chain (IC) and the dynactin p150(Glued); however, the interface and mechanism that regulates this interaction remains poorly defined. Herein, we use multiple methods to show the N-terminus of mammalian dynein IC, residues 10-44, is sufficient for binding p150(Glued). Consistent with this mapping, monoclonal antibodies that antagonize the dynein-dynactin interaction also bind to this region of the IC. Furthermore, double and triple alanine point mutations spanning residues 6 to 19 in the yeast IC homolog, …
Molecular Determinants Of Epidermal Growth Factor Binding: A Molecular Dynamics Study., Jeffrey M Sanders, Matthew E Wampole, Mathew L. Thakur, Eric Wickstrom
Molecular Determinants Of Epidermal Growth Factor Binding: A Molecular Dynamics Study., Jeffrey M Sanders, Matthew E Wampole, Mathew L. Thakur, Eric Wickstrom
Department of Biochemistry and Molecular Biology Faculty Papers
The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family that plays a role in multiple cellular processes. Activation of EGFR requires binding of a ligand on the extracellular domain to promote conformational changes leading to dimerization and transphosphorylation of intracellular kinase domains. Seven ligands are known to bind EGFR with affinities ranging from sub-nanomolar to near micromolar dissociation constants. In the case of EGFR, distinct conformational states assumed upon binding a ligand is thought to be a determining factor in activation of a downstream signaling network. Previous biochemical studies suggest the existence of both …
Structural Implications For Selective Targeting Of Parps., Jamin D Steffen, Md, Jonathan Brody, Md, Roger S Armen, Md, John M Pascal, Md
Structural Implications For Selective Targeting Of Parps., Jamin D Steffen, Md, Jonathan Brody, Md, Roger S Armen, Md, John M Pascal, Md
Department of Biochemistry and Molecular Biology Faculty Papers
Poly(ADP-ribose) polymerases (PARPs) are a family of enzymes that use NAD(+) as a substrate to synthesize polymers of ADP-ribose (PAR) as post-translational modifications of proteins. PARPs have important cellular roles that include preserving genomic integrity, telomere maintenance, transcriptional regulation, and cell fate determination. The diverse biological roles of PARPs have made them attractive therapeutic targets, which have fueled the pursuit of small molecule PARP inhibitors. The design of PARP inhibitors has matured over the past several years resulting in several lead candidates in clinical trials. PARP inhibitors are mainly used in clinical trials to treat cancer, particularly as sensitizing agents …
Possible Steps Of Complete Disassembly Of Post-Termination Complex By Yeast Eef3 Deduced From Inhibition By Translocation Inhibitors., Shinya Kurata, Ben Shen, Jun O Liu, Nono Takeuchi, Akira Kaji, Hideko Kaji
Possible Steps Of Complete Disassembly Of Post-Termination Complex By Yeast Eef3 Deduced From Inhibition By Translocation Inhibitors., Shinya Kurata, Ben Shen, Jun O Liu, Nono Takeuchi, Akira Kaji, Hideko Kaji
Department of Biochemistry and Molecular Biology Faculty Papers
Ribosomes, after one round of translation, must be recycled so that the next round of translation can occur. Complete disassembly of post-termination ribosomal complex (PoTC) in yeast for the recycling consists of three reactions: release of tRNA, release of mRNA and splitting of ribosomes, catalyzed by eukaryotic elongation factor 3 (eEF3) and ATP. Here, we show that translocation inhibitors cycloheximide and lactimidomycin inhibited all three reactions. Cycloheximide is a non-competitive inhibitor of both eEF3 and ATP. The inhibition was observed regardless of the way PoTC was prepared with either release factors or puromycin. Paromomycin not only inhibited all three reactions …
Global Cellular Regulation Including Cardiac Function By Post-Translational Protein Arginylation., Hideko Kaji, Akira Kaji
Global Cellular Regulation Including Cardiac Function By Post-Translational Protein Arginylation., Hideko Kaji, Akira Kaji
Department of Biochemistry and Molecular Biology Faculty Papers
In this issue a very significant contribution to cardiology describing critical roles of ATE1 appears by Kurosaka et al. [1]. In view of this paper, as the discoverers of ATE1, we have been asked to contribute an article (editorial) regarding ATE1 (enzyme which transfers arginine from arginyl tRNA to protein acceptors). This short article consists of three sections: 1) a historical anecdote describing how ATE1 was discovered; 2) its possible role in aging and cellular transformation, and most importantly; 3) its role in the development and maintenance of cardiac activity. The last section has direct bearing to the Kurosaka …
Engrailed Cooperates Directly With Extradenticle And Homothorax On A Distinct Class Of Homeodomain Binding Sites To Repress Sloppy Paired., Miki Fujioka, Brian Gebelein, Zenobia C Cofer, Richard S Mann, James B Jaynes
Engrailed Cooperates Directly With Extradenticle And Homothorax On A Distinct Class Of Homeodomain Binding Sites To Repress Sloppy Paired., Miki Fujioka, Brian Gebelein, Zenobia C Cofer, Richard S Mann, James B Jaynes
Department of Biochemistry and Molecular Biology Faculty Papers
Even skipped (Eve) and Engrailed (En) are homeodomain-containing transcriptional repressors with similar DNA binding specificities that are sequentially expressed in Drosophila embryos. The sloppy-paired (slp) locus is a target of repression by both Eve and En. At blastoderm, Eve is expressed in 7 stripes that restrict the posterior border of slp stripes, allowing engrailed (en) gene expression to be initiated in odd-numbered parasegments. En, in turn, prevents expansion of slp stripes after Eve is turned off. Prior studies showed that the two tandem slp transcription units are regulated by cis-regulatory modules (CRMs) with activities that overlap in space and time. …
Protein Synthesis Factors (Rf1, Rf2, Rf3, Rrf, And Tmrna) And Peptidyl-Trna Hydrolase Rescue Stalled Ribosomes At Sense Codons., Serafín Vivanco-Domínguez, José Bueno-Martínez, Gloria León-Avila, Nobuhiro Iwakura, Akira Kaji, Hideko Kaji, Gabriel Guarneros
Protein Synthesis Factors (Rf1, Rf2, Rf3, Rrf, And Tmrna) And Peptidyl-Trna Hydrolase Rescue Stalled Ribosomes At Sense Codons., Serafín Vivanco-Domínguez, José Bueno-Martínez, Gloria León-Avila, Nobuhiro Iwakura, Akira Kaji, Hideko Kaji, Gabriel Guarneros
Department of Biochemistry and Molecular Biology Faculty Papers
During translation, ribosomes stall on mRNA when the aminoacyl-tRNA to be read is not readily available. The stalled ribosomes are deleterious to the cell and should be rescued to maintain its viability. To investigate the contribution of some of the cellular translation factors on ribosome rescuing, we provoked stalling at AGA codons in mutants that affected the factors and then analyzed the accumulation of oligopeptidyl (peptides of up to 6 amino acid residues, oligopep-)-tRNA or polypeptidyl (peptides of more than 300 amino acids in length, polypep-)-tRNA associated with ribosomes. Stalling was achieved by starvation for aminoacyl-tRNA(Arg4) upon induced expression of …
Structural Insights Into Initial And Intermediate Steps Of The Ribosome-Recycling Process, Takeshi Yokoyama, Tanvir R. Shaikh, Nobuhiro Iwakura, Hideko Kaji, Akira Kaji, Rajendra K. Agrawal
Structural Insights Into Initial And Intermediate Steps Of The Ribosome-Recycling Process, Takeshi Yokoyama, Tanvir R. Shaikh, Nobuhiro Iwakura, Hideko Kaji, Akira Kaji, Rajendra K. Agrawal
Department of Biochemistry and Molecular Biology Faculty Papers
The ribosome recycling factor (RRF) and elongation factor G (EF-G) disassemble the 70S post-termination complex (PoTC) into mRNA, tRNA, and two ribosomal subunits. We have determined cryo-EM structures of the PoTC•RRF complex, with and without EF-G. We find that domain II of RRF initially interacts with universally conserved residues of the 23S rRNA helices 43 and 95, and protein L11 within the 50S ribosomal subunit. Upon EF-G binding, both RRF and tRNA are driven toward the tRNA-exit (E) site, with a large rotational movement of domain II of RRF toward the 30S ribosomal subunit. During this intermediate step of the …
Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes
Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes
Department of Biochemistry and Molecular Biology Faculty Papers
In order to investigate regulation and redundancy within the sloppy paired (slp) locus, we analyzed 30 kilobases of DNA encompassing the tandem, coordinately regulated slp1 and slp2 transcription units. We found a remarkable array of stripe enhancers with overlapping activities surrounding the slp1 transcription unit, and, unexpectedly, glial cell enhancers surrounding slp2. The slp stripe regulatory region generates 7 stripes at blastoderm, and later 14 stripes that persist throughout embryogenesis. Phylogenetic analysis among drosophilids suggests that the multiplicity of stripe enhancers did not evolve through recent duplication. Most of the direct integration among cis-regulatory modules appears to be simply additive, …
Synergetic Effect Of Recoverin And Calmodulin On Regulation Of Rhodopsin Kinase., Ilya I Grigoriev, Ivan I Senin, Natalya K Tikhomirova, Konstantin E Komolov, Sergei E Permyakov, Evgeni Yu Zernii, Karl-Wilhelm Koch, Pavel P Philippov
Synergetic Effect Of Recoverin And Calmodulin On Regulation Of Rhodopsin Kinase., Ilya I Grigoriev, Ivan I Senin, Natalya K Tikhomirova, Konstantin E Komolov, Sergei E Permyakov, Evgeni Yu Zernii, Karl-Wilhelm Koch, Pavel P Philippov
Department of Biochemistry and Molecular Biology Faculty Papers
Phosphorylation of photoactivated rhodopsin by rhodopsin kinase (RK or GRK1), a first step of the phototransduction cascade turnoff, is under the control of Ca(2+)/recoverin. Here, we demonstrate that calmodulin, a ubiquitous Ca(2+)-sensor, can inhibit RK, though less effectively than recoverin does. We have utilized the surface plasmon resonance technology to map the calmodulin binding site in the RK molecule. Calmodulin does not interact with the recoverin-binding site within amino acid residues M1-S25 of the enzyme. Instead, the high affinity calmodulin binding site is localized within a stretch of amino acid residues V150-K175 in the N-terminal regulatory region of RK. Moreover, …
Testosterone Treatment Fails To Accelerate Disease In A Transgenic Mouse Model Of Spinal And Bulbar Muscular Atrophy., Erica S Chevalier-Larsen, Diane E Merry
Testosterone Treatment Fails To Accelerate Disease In A Transgenic Mouse Model Of Spinal And Bulbar Muscular Atrophy., Erica S Chevalier-Larsen, Diane E Merry
Department of Biochemistry and Molecular Biology Faculty Papers
Evidence from multiple animal models demonstrates that testosterone plays a crucial role in the progression of symptoms in spinal and bulbar muscular atrophy (SBMA), a condition that results in neurodegeneration and muscle atrophy in affected men. Mice bearing a transgene encoding a human androgen receptor (AR) that contains a stretch of 112 glutamines (expanded polyglutamine tract; AR112Q mice) reproduce several aspects of the human disease. We treated transgenic male AR112Q mice with testosterone for 6 months. Surprisingly, testosterone treatment of AR112Q males did not exacerbate the disease. Although transgenic AR112Q males exhibited functional deficits when compared with non-transgenics, long-term testosterone …
Mitochondrial Lysyl-Trna Synthetase Independent Import Of Trna Lysine Into Yeast Mitochondria., Naresh Babu V Sepuri, Madhavi Gorla, Michael P King
Mitochondrial Lysyl-Trna Synthetase Independent Import Of Trna Lysine Into Yeast Mitochondria., Naresh Babu V Sepuri, Madhavi Gorla, Michael P King
Department of Biochemistry and Molecular Biology Faculty Papers
Aminoacyl tRNA synthetases play a central role in protein synthesis by charging tRNAs with amino acids. Yeast mitochondrial lysyl tRNA synthetase (Msk1), in addition to the aminoacylation of mitochondrial tRNA, also functions as a chaperone to facilitate the import of cytosolic lysyl tRNA. In this report, we show that human mitochondrial Kars (lysyl tRNA synthetase) can complement the growth defect associated with the loss of yeast Msk1 and can additionally facilitate the in vitro import of tRNA into mitochondria. Surprisingly, the import of lysyl tRNA can occur independent of Msk1 in vivo. This suggests that an alternative mechanism is present …