Medical Biochemistry Commons^™

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 …

The Impact Of Nucleoside Sugar Modification On Biochemical Dna Transactions, Adides Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Discrimination by DNA polymerases controls the fidelity of DNA replication, and reduced fidelity results in mutations essential in the etiology of cancer. Polymerase discrimination operates at both dNTP insertion and subsequent elongation steps, and involves several energetic and structural factors that are as yet incompletely understood. While base pairing interactions have been studied extensively, substantially less is known about the role of sugar structure and conformation for polymerase incorporation and extension. In these studies we examined, systematically, the role of sugar structure and conformation on polymerase selection of the dNTP for insertion and polymerase elongation. To accomplish these goals, we …

Pathobiological Implications Of The Expression Of Egfr, Pakt, Nf-Κb And Mic-1 In Prostate Cancer Stem Cells And Their Progenies., Murielle Mimeault, Sonny L. Johansson, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

The progression of prostate cancers (PCs) to locally invasive, androgen-independent and metastatic disease states is generally associated with treatment resistance and disease relapse. The present study was undertaken to establish the possibility of using a combination of specific oncogenic products, including epidermal growth factor receptor (EGFR), pAkt, nuclear factor-kappaB (NF-κB) and macrophage inhibitory cytokine-1 (MIC-1) as biomarkers and therapeutic targets for optimizing the management of patients with localized PC at earlier disease stages. The immunohistochemical and immunofluorescence data have revealed that the expression levels of EGFR, Ser(473)-pAkt, NF-κB p65 and MIC-1 proteins were significantly enhanced in the same subset of …

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, …

Mir-25 Targets Tnf-Related Apoptosis Inducing Ligand (Trail) Death Receptor-4 And Promotes Apoptosis Resistance In Cholangiocarcinoma., Nataliya Razumilava, Steve F. Bronk, Rory L. Smoot, Christian D. Fingas, Nathan W. Werneburg, Lewis R. Roberts, Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

It has been established that microRNA expression and function contribute to phenotypic features of malignant cells, including resistance to apoptosis. Although targets and functional roles for a number of microRNAs have been described in cholangiocarcinoma, many additional microRNAs dysregulated in this tumor have not been assigned functional roles. In this study, we identify elevated miR-25 expression in malignant cholangiocarcinoma cell lines as well as patient samples. In cultured cells, treatment with the Smoothened inhibitor, cyclopamine, reduced miR-25 expression, suggesting Hedgehog signaling stimulates miR-25 production. Functionally, miR-25 was shown to protect cells against TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Correspondingly, antagonism of …

Synthetic Peptides Derived From The Sequence Of A Lasso Peptide Microcin J25 Show Antibacterial Activity, Rania Soudy, Liru Wang, Kamaljit Kaur

Pharmacy Faculty Articles and Research

Microcin J25 (MccJ25) is a plasmid-encoded, ribosomally synthesized antibacterial peptide with a unique lasso structure. The lasso structure, produced with the aid of two processing enzymes, provides exceptional stability to MccJ25. We report the synthesis of six peptides (1–6), derived from the MccJ25 sequence, that are designed to form folded conformation by disulfide bond formation and electrostatic or hydrophobic interactions. Two peptides (1 and 6) display good activity against Salmonella newport, and are the first synthetic derivatives of MccJ25 that are bactericidal. Peptide 1 displays potent activity against several Salmonella strains including two …

Evaluation Of The Role Of Oxidative Stress, Inflammation And Apoptosis In The Pulmonary And The Hepatic Toxicity Induced By Cerium Oxide Nanoparticles Following Intratracheal Instillation In Male Sprague-Dawley Rats, Siva Krishna Nalabotu

Theses, Dissertations and Capstones

The field of nanotechnology is rapidly progressing with potential applications in the automobile, healthcare, electronics, cosmetics, textiles, information technology, and environmental sectors. Nanomaterials are engineered structures with at least one dimension of 100 nanometers or less. With increased applications of nanotechnology, there are increased chances of exposure to manufactured nanomaterials. Recent reports on the toxicity of engineered nanomaterials have given scientific and regulatory agencies concerns over the safety of nanomaterials. Specifically, the Organization for Economic Co-operation and Development (OECD) has identified fourteen high priority nanomaterials for study. Cerium oxide (CeO2) nanoparticles are one among the high priority group. Recent data …

The Use Of Cerium Oxide And Curcumin Nanoparticles As Therapeutic Agents For The Treatment Of Ventricular Hypertrophy Following Pulmonary Arterial Hypertension, Madhukar Babu Kolli

Theses, Dissertations and Capstones

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by inflammation, increased pulmonary vascular resistance, right ventricular failure and premature death. Monocrotaline (MCT) has been used to induce PAH in laboratory rats. Previous in vitro and in vivo work suggested that cerium oxide (CeO2)-and curcumin nanoparticles exhibit anti-inflammatory activity; however, it is unknown if these materials are effective for the treatment of PAH induced cardiac hypertrophy. To determine the efficacy of CeO2 nanoparticle treatment in preventing MCT-induced RV hypertrophy, male Sprague Dawley rats were divided into one of three groups (control, MCT, or MCT + CeO2 nanoparticle, n=6/group). …

Nuclear Receptor Expression And Characterization Of The Major Retinoic Acid Target Gene In Melanoma, Linda L. Eastham

Theses, Dissertations and Capstones

Malignant melanoma is the primary cause of death from all diseases arising from the skin and it is one of the most resistant tumors to standard treatment options. The increasing incidence of melanoma and its poor prognosis makes the understanding of melanoma cell biology very important. Melanoma progression is a complex, multi-step process, and the molecular events leading to melanoma tumor cell proliferation and invasion still need further examination. This study is focused on measuring the expression and activity of two specific genes and their protein counterparts that are altered during melanoma progression. It also examines the mechanism through which …

The Role Of Vascular Endothelial Growth Factor At The Blood-Brain Barrier In Diabetes, Aileen J. Marcelo

Theses, Dissertations and Capstones

Diabetes is a risk factor for stroke and vascular dementia. Clinical studies using gadolinium-magnetic resonance imaging techniques have shown diabetic patients exhibit a permeability increase at the blood-brain barrier (BBB) (Starr et al, 2003). The BBB, a vascular interface at the level of brain microvascular vessels, functions to provide nutrients and oxygen from the peripheral circulation, mediates waste efflux from the brain, and protects the brain from toxins. These functions are due to the presence of tight junction proteins. Animal studies have shown increased BBB permeability is due to a decrease in these proteins (Hawkins et al, 2007). Based on …

Apo A1 Mimetic Rescues The Diabetic Phenotype Of Ho-2 Knockout Mice Via An Increase In Ho-1 Adiponectin And Lkbi Signaling Pathway, Jian Cao, Nitin Puri, Komal Sodhi, Lars Bellner, Nader G. Abraham, Attallah Kappas

Biochemistry and Microbiology

Insulin resistance, with adipose tissue dysfunction, is one of the hallmarks of metabolic syndrome. We have reported a metabolic syndrome-like phenotype in heme oxygenase (HO)-2 knockout mice, which presented with concurrent HO-1 deficiency and were amenable to rescue by an EET analog. Apo A-I mimetic peptides, such as L-4F, have been shown to induce HO-1 expression and decrease oxidative stress and adiposity. In this study we aimed to characterize alleviatory effects of HO-1 induction (if any) on metabolic imbalance observed in HO-2 KO mice. In this regard, HO-2^(−/−) mice were injected with 2 mg/kg/day L-4F, or vehicle, i.p., for …

Consumption Of High Ω-3 Fatty Acid Diet Suppressed Prostate Tumorigenesis In C3(1) Tag Mice, Juliana A. Akinsete, Gabriela Ion, Theodore R. Witte, W. Elaine Hardman

Biochemistry and Microbiology

Prostate cancer incidence and mortality are high in the Western world and high ω-6/ω-3 PUFA in the Western diet may be a contributing factor. We investigated whether changing from a diet that approximates ω-6 fat content of the Western diet to a high ω-3 fat diet at adulthood might reduce prostate cancer risk. Female SV 129 mice that had consumed a high ω-6 diet containing corn oil for 2 weeks were bred with homozygous C3(1)Tag transgenic male mice. All male offspring were weaned to the corn oil diet (CO) until postpuberty when half of the male offspring were transferred to …

Synthesis And Anti–Hiv Activities Of Symmetrical Dicarboxylate Esters Of Dinucleoside Reverse Transcriptase Inhibitors, Hitesh K. Agarwal, Karen W. Buckheit, Robert W. Buckheit Jr., Keykavous Parang

Pharmacy Faculty Articles and Research

Three nucleoside analogues, 3′-fluoro-2′,3′-dideoxythymidine (FLT), 3′-azido-2′,3′-dideoxythymidine (AZT), and 2′,3′-dideoxy-3′-thiacytidine (3TC) were conjugated with three different dicarboxylic acids to afford the long chain dicarboxylate esters of nucleosides. In general, dinucleoside ester conjugates of FLT and 3TC with long chain dicarboxylic acids exhibited higher anti-HIV activity than their parent nucleosides. Dodecanoate and tetradecanoate dinucleoside ester derivatives of FLT were found to be the most potent compounds with EC50 values of 0.8–1.0 nM and 3–4 nM against HIV-1US/92/727 and HIV-1IIIB cells, respectively. The anti-HIV activity of the 3TC conjugates containing long chain dicarboxylate diester (EC50 = 3–60 nM) was improved by 1.5–66 fold …

Identification Of Sumoylated Proteins And Investigation Of Protein Ubiquitination In The Nf-Κb Pathway, Xiaoyan Liu

Theses and Dissertations--Molecular and Cellular Biochemistry

SUMOylation and ubiquitination are important post-translational modifications. While ubiquitination is well known for targeting proteins for degradation, SUMOylation often regulates the intracellular localization of substrates. In the first project of this dissertation, we developed proteomic strategies to identify novel SUMOylated proteins in mammalian cells. In the second project, we investigated the regulation of protein ubiquitination in the NF-κB signaling pathway in the context of Paget’s disease of bone (PDB).

Identification of SUMOylated proteins has been a challenge because of low abundance of SUMOylation substrates. Here, we utilized a mass spectrometry (MS)-based proteomic approach to identify novel SUMOylated proteins in mammalian …

One-Pot Regioselective Synthesis Of Tetrahydroindazolones And Evaluation Of Their Anti-Proliferative And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Rakesh Tiwari, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar

Pharmacy Faculty Articles and Research

A number of 2-substituted tetrahydroindazolones were synthesized by three-component condensation reaction of 1,3- diketones, substituted hydrazines, benzaldehydes, and Yb(OTf)3 as a catalyst in [bmim][BF4] ionic liquid using a simple, efficient, and economical one-pot method. The synthesized tetrahydroindazolones were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. 3,4-Dichlorophenyl tetrahydroindazolone derivative (15) inhibited the cell proliferation of HT-29 and SK-OV-3 cells by 62% and 58%, respectively. 2,3-Diphenylsubstituted tetrahydroindazolone derivatives, 19, 25, and 33, inhibited the cell proliferation of HT-29 cells by 6572% at a concentration of 50 μM. In general, the …

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 …

Autophagy And Apoptotic Genes Implicated In Alzheimer’S Disease Are Modulated Following Infection Of Neuronal Cells With Chlamydia Pneumoniae, Denah M. Appelt, Ian Kohler, Annette K. Slutter, Juliana Zoga, Susan T. Hingley, Brian J. Balin

Scholarly Posters

Background: The focus of the current studies was to determine the relationship between the molecular mechanisms interconnecting autophagy and apoptosis following Chlamydia pneumoniae infection in neuronal cells. Dysfunctions in apoptosis and autophagy have been implicated in the neurodegeneration associated with Alzheimer’s disease (AD). Autophagy in AD pathogenesis has been shown to play a role in amyloid processing through the endosomal-lysosomal system. Apoptosis may contribute to the neuronal cell loss observed in AD; however, there is limited evidence of the apoptotic process proceeding to terminal completion. Although Aβ1-42 has been shown to induce apoptosis in neurons and may be an early …

Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan

Chemistry Faculty Publications

The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were successfully employed in the preparation of phosphonic and boronic esters and acids. The latter were tested for heat release with a microcombustion calorimeter (ASTM D7309) to determine the potential for heat release reduction of these flame retardant molecules. The results showed that the addition of boronic or phosphonic acids greatly lowered the heat release, due to a condensed phase (char formation) mechanism. Adding ester groups to the boronic acids or …

Characterization Of A Hyperthermophilic Redox Protein, Rubredoxin, As A Potential Targeted Cancer Therapeutic, Siri Lakshmi Chirumamilla

PCOM Biomedical Studies Student Scholarship

Cancer is an elusive neoplastic disease that claims the lives of many people around the world every year. Though treatments have become more specific to the different types of cancer, the need remains for antineoplastic drugs that target cancer cells and leave normal cells unharmed, with little to no systemic toxicity. The search for a targeted cancer therapeutic is necessary and urgent, and Pyrococcus furiosus rubredoxin might be such a tool. Rubredoxin is a small (53 amino acids), water soluble, non-heme iron electron transfer protein that contains an iron atom cofactor bound by the sulfurs of four cysteine residues, which …

The Formin Fmnl3 Is A Cytoskeletal Regulator Of Angiogenesis, Clare Hetheridge, Alice N. Scott, Rajeeb K. Swain, John W. Copeland, Henry N. Higgs

Dartmouth Scholarship

The process of angiogenesis requires endothelial cells (ECs) to undergo profound changes in shape and polarity. Although this must involve remodelling of the EC cytoskeleton, little is known about this process or the proteins that control it. We used a co-culture assay of angiogenesis to examine the cytoskeleton of ECs actively undergoing angiogenic morphogenesis. We found that elongation of ECs during angiogenesis is accompanied by stabilisation of microtubules and their alignment into parallel arrays directed at the growing tip. In other systems, similar microtubule alignments are mediated by the formin family of cytoskeletal regulators. We screened a library of human …

Proteasome Regulation Of Caspase-8: Significance In Cancer, Michael Vincent Fiandalo

Theses and Dissertations--Molecular and Cellular Biochemistry

Anti-tumor therapeutic strategies based on combinations of chemotherapeutic agents with a death inducing ligand such as TNF-α Related Apoptosis Inducing Ligand (TRAIL), are directed towards selective and effective cancer cell apoptosis and enhanced therapeutic response. We previously demonstrated that proteasome inhibition sensitizes TRAIL resistant prostate cancer cells to TRAIL-mediated apoptosis via stabilization of the active p18 subunit of initiator caspase-8. The present study investigated the functional link between caspase-8 and the proteasome, by analyzing the impact of caspase-8 ubiquitination and proteasomal degradation on the outcomes of the extrinsic apoptosis pathway in cancer cells. Caspase-8 ubiquitination status was assessed by polyubiquitin …

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 …

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, …

Redefining Onyx Hd 500 In The Flow Diversion Era., Richard Tyler Dalyai, Ciro Randazzo, George Ghobrial, L Fernando Gonzalez, Stavropoula I Tjoumakaris, Aaron S Dumont, Robert H Rosenwasser, Pascal Jabbour

Department of Neurosurgery Faculty Papers

We report the largest US case series results using Onyx HD-500 (EV3), a new liquid embolic agent, in the successful treatment of 21 patients with wide-neck intracranial aneurysms (mean size 4.5 mm), which are at increased risk of incomplete occlusion or recanalization with standard endovascular intervention utilizing detachable platinum coils. All aneurysms were located in the anterior circulation, and three aneurysms presented as acute subarachnoid hemorrhages. Complete aneurysm occlusion was present in 19 of 21 patients (90%). On six-month followup, one patient with an initially small residual neck progressed to total occlusion. Aneurysm recanalization was not detected in any patients …

Role Of Myosin Light Chain Kinase In Binge Ethanol And Burn Injury-Induced Intestinal Barrier Dysfunction, Anita Zahs

Dissertations

Ethanol is a common factor in traumatic injury, including burn injury. Previous studies from our laboratory indicate that ethanol increases both pulmonary and gastrointestinal inflammation as well as susceptibility to infection in burn-injured mice; however, the mechanisms of these responses are not entirely known. Moreover, after burn injury, bacteria and their products leak out of the intestinal lumen and into the bloodstream. These bacteria can disperse throughout the body leading to pulmonary damage, acute lung injury, sepsis, and death. Ethanol in combination with burn injury has been shown to decrease intestinal barrier function greater than either insult alone. Long (210 …

Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. …