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Skin Bacterial Metacommunities Of San Francisco Bay Area Salamanders Are Structured By Host Genus And Habitat Quality., Shannon Buttimer, Obed Hernandez-Gomez, Erica Bree Rosenblum Dec 2021

Skin Bacterial Metacommunities Of San Francisco Bay Area Salamanders Are Structured By Host Genus And Habitat Quality., Shannon Buttimer, Obed Hernandez-Gomez, Erica Bree Rosenblum

Natural Sciences and Mathematics | Faculty Scholarship

Host-associated microbial communities can influence physiological processes of macroorganisms, including contributing to infectious disease resistance. For instance, some bacteria that live on amphibian skin produce antifungal compounds that inhibit two lethal fungal pathogens, Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Therefore, differences in microbiome composition among host species or populations within a species can contribute to variation in susceptibility to Bd/Bsal. This study applies 16S rRNA sequencing to characterize the skin bacterial microbiomes of three widespread terrestrial salamander genera native to the western United States. Using a metacommunity structure analysis, we identified dispersal barriers for these influential bacteria between salamander …


The Antimalarial Mmv688533 Provides Potential For Single-Dose Cures With A High Barrier To, James M. Murithi, Cécile Pascal, Jade Bath, Xavier Boulenc, Nina F. Gnädig, Charisse Flerida A. Pasaje, Kelly Rubiano, Tomas Yeo, Sachel Mok, Sylvie Klieber, Paul Desert, María Belén Jiménez-Díaz, Jutta Marfurt, Mélanie Rouillier, Mohammed H. Cherkaoui-Rbati, Nathalie Gobeau, Sergio Wittlin, Anne-Catrin Uhlemann, Ric N. Price, Grennady Wirjanata, Rintis Noviyanti, Patrick Tumwebaze, Roland A. Cooper, Philip J. Rosenthal, Laura M. Sanz, Francisco-Javier Gamo, Jayan Joseph, Shivendra Singh, Sridevi Bashyam, Jean Michel Augereau, Elie Giraud, Tanguy Bozec, Thierry Vermat, Gilles Tuffal, Jean-Michel Guillon, Jérôme Menegotto, Laurent Sallé, Guillaume Louit, Marie-José Cabanis, Marie Françoise Nicolas, Michel Doubovetzky, Rita Merino, Nadir Bessila, Iñigo Angulo-Barturen, Delphine Baud, Lidiya Bebrevska, Fanny Escudié, Jacquin C. Niles, Benjamin Blasco, Simon Campbell, Gilles Courtemanche, Laurent Fraisse, Alain Pellet, David A. Fidock, Didier Leroy Jul 2021

The Antimalarial Mmv688533 Provides Potential For Single-Dose Cures With A High Barrier To, James M. Murithi, Cécile Pascal, Jade Bath, Xavier Boulenc, Nina F. Gnädig, Charisse Flerida A. Pasaje, Kelly Rubiano, Tomas Yeo, Sachel Mok, Sylvie Klieber, Paul Desert, María Belén Jiménez-Díaz, Jutta Marfurt, Mélanie Rouillier, Mohammed H. Cherkaoui-Rbati, Nathalie Gobeau, Sergio Wittlin, Anne-Catrin Uhlemann, Ric N. Price, Grennady Wirjanata, Rintis Noviyanti, Patrick Tumwebaze, Roland A. Cooper, Philip J. Rosenthal, Laura M. Sanz, Francisco-Javier Gamo, Jayan Joseph, Shivendra Singh, Sridevi Bashyam, Jean Michel Augereau, Elie Giraud, Tanguy Bozec, Thierry Vermat, Gilles Tuffal, Jean-Michel Guillon, Jérôme Menegotto, Laurent Sallé, Guillaume Louit, Marie-José Cabanis, Marie Françoise Nicolas, Michel Doubovetzky, Rita Merino, Nadir Bessila, Iñigo Angulo-Barturen, Delphine Baud, Lidiya Bebrevska, Fanny Escudié, Jacquin C. Niles, Benjamin Blasco, Simon Campbell, Gilles Courtemanche, Laurent Fraisse, Alain Pellet, David A. Fidock, Didier Leroy

Natural Sciences and Mathematics | Faculty Scholarship

The emergence and spread of Plasmodium falciparum resistance to first-line antimalarials creates an imperative to identify and develop potent preclinical candidates with distinct modes of action. Here, we report the identification of MMV688533, an acylguanidine that was developed following a whole-cell screen with compounds known to hit high-value targets in human cells. MMV688533 displays fast parasite clearance in vitro and is not cross-resistant with known antimalarials. In a P. falciparum NSG mouse model, MMV688533 displays a long-lasting pharmacokinetic profile and excellent safety. Selection studies reveal a low propensity for resistance, with modest loss of potency mediated by point mutations in …


Development Of A Highly Selective Plasmodium Falciparum Proteasome Inhibitor With Anti-Malaria Activity In Humanized Mice., Wenhu Zhan, Hao Zhang, John Ginn, Annie Leung, Yi J. Liu, Mayako Michino, Akinori Toita, Rei Okamoto, Tzu-Tshin Wong, Toshihiro Imaeda, Ryoma Hara, Takafumi Yukawa, Sevil Chelebieva, Patrick K. Tumwebaze, Maria Jose Lafuente-Monasterio, Maria Santos Martinez-Martinez, Jeremie Vendome, Thijs Beuming, Kenjiro Sato, Kazuyoshi Aso, Philip J. Rosenthal, Roland A. Cooper, Peter T Meinke, Carl F. Nathan, Laura A. Kirkman, Gang Lin Apr 2021

Development Of A Highly Selective Plasmodium Falciparum Proteasome Inhibitor With Anti-Malaria Activity In Humanized Mice., Wenhu Zhan, Hao Zhang, John Ginn, Annie Leung, Yi J. Liu, Mayako Michino, Akinori Toita, Rei Okamoto, Tzu-Tshin Wong, Toshihiro Imaeda, Ryoma Hara, Takafumi Yukawa, Sevil Chelebieva, Patrick K. Tumwebaze, Maria Jose Lafuente-Monasterio, Maria Santos Martinez-Martinez, Jeremie Vendome, Thijs Beuming, Kenjiro Sato, Kazuyoshi Aso, Philip J. Rosenthal, Roland A. Cooper, Peter T Meinke, Carl F. Nathan, Laura A. Kirkman, Gang Lin

Natural Sciences and Mathematics | Faculty Scholarship

Plasmodium falciparum proteasome (Pf20S) inhibitors are active against Plasmodium at multiple stages-erythrocytic, gametocyte, liver, and gamete activation stages-indicating that selective Pf20S inhibitors possess the potential to be therapeutic, prophylactic, and transmission-blocking antimalarials. Starting from a reported compound, we developed a noncovalent, macrocyclic peptide inhibitor of the malarial proteasome with high species selectivity and improved pharmacokinetic properties. The compound demonstrates specific, time-dependent inhibition of the β5 subunit of the Pf20S, kills artemisinin-sensitive and artemisinin-resistant P. falciparum isolates in vitro and reduces parasitemia in humanized, P. falciparum-infected mice.


Genetic And Metabolomic Architecture Of Variation In Diet Restriction-Mediated Lifespan Extension In Drosophila., Kelly Jin, Kenneth A. Wilson, Jennifer N. Beck, Christopher S. Nelson, George W. Brownridge Iii, Benjamin R. Harrison, Danijel Djukovic, Daniel Raftery, Rachel B. Brem, Shiqing Yu, Mathias Drton, Ali Shojaie, Pankaj Kapahi, Daniel Promislow Jul 2020

Genetic And Metabolomic Architecture Of Variation In Diet Restriction-Mediated Lifespan Extension In Drosophila., Kelly Jin, Kenneth A. Wilson, Jennifer N. Beck, Christopher S. Nelson, George W. Brownridge Iii, Benjamin R. Harrison, Danijel Djukovic, Daniel Raftery, Rachel B. Brem, Shiqing Yu, Mathias Drton, Ali Shojaie, Pankaj Kapahi, Daniel Promislow

Natural Sciences and Mathematics | Student Professional Publications

In most organisms, dietary restriction (DR) increases lifespan. However, several studies have found that genotypes within the same species vary widely in how they respond to DR. To explore the mechanisms underlying this variation, we exposed 178 inbred Drosophila melanogaster lines to a DR or ad libitum (AL) diet, and measured a panel of 105 metabolites under both diets. Twenty four out of 105 metabolites were associated with the magnitude of the lifespan response. These included proteinogenic amino acids and metabolites involved in α-ketoglutarate (α-KG)/glutamine metabolism. We confirm the role of α-KG/glutamine synthesis pathways in the DR response through genetic …


A Novel Rapamycin Analog Is Highly Selective For Mtorc1 In Vivo., Katherine H. Schreiber, Sebastian I. Arriola Apelo, Deyang Yu, Jacqueline A Brinkman, Michael C Velarde, Faizan A Syed, Chen-Yu Liao, Emma L. Baar, Kathryn A. Carbajal, Dawn S. Sherman, Denise Ortiz, Regina Brunauer, Shany E. Yang, Stelios T Tzannis, Brian K Kennedy, Dudley W Lamming Jul 2019

A Novel Rapamycin Analog Is Highly Selective For Mtorc1 In Vivo., Katherine H. Schreiber, Sebastian I. Arriola Apelo, Deyang Yu, Jacqueline A Brinkman, Michael C Velarde, Faizan A Syed, Chen-Yu Liao, Emma L. Baar, Kathryn A. Carbajal, Dawn S. Sherman, Denise Ortiz, Regina Brunauer, Shany E. Yang, Stelios T Tzannis, Brian K Kennedy, Dudley W Lamming

Natural Sciences and Mathematics | Student Professional Publications

Rapamycin, an inhibitor of mechanistic Target Of Rapamycin Complex 1 (mTORC1), extends lifespan and shows strong potential for the treatment of age-related diseases. However, rapamycin exerts metabolic and immunological side effects mediated by off-target inhibition of a second mTOR-containing complex, mTOR complex 2. Here, we report the identification of DL001, a FKBP12-dependent rapamycin analog 40x more selective for mTORC1 than rapamycin. DL001 inhibits mTORC1 in cell culture lines and in vivo in C57BL/6J mice, in which DL001 inhibits mTORC1 signaling without impairing glucose homeostasis and with substantially reduced or no side effects on lipid metabolism and the immune system. In …


Embryonic Origin And Genetic Basis Of Cave Associated Phenotypes In The Isopod Crustacean Asellus Aquaticus., Hafasa Mojaddidi, Franco Fernandez, Priscilla A. Erickson, Meredith E. Protas Nov 2018

Embryonic Origin And Genetic Basis Of Cave Associated Phenotypes In The Isopod Crustacean Asellus Aquaticus., Hafasa Mojaddidi, Franco Fernandez, Priscilla A. Erickson, Meredith E. Protas

Natural Sciences and Mathematics | Faculty Scholarship

Characteristics common to animals living in subterranean environments include the reduction or absence of eyes, lessened pigmentation and enhanced sensory systems. How these characteristics have evolved is poorly understood for the majority of cave dwelling species. In order to understand the evolution of these changes, this study uses an invertebrate model system, the freshwater isopod crustacean, Asellus aquaticus, to examine whether adult differences between cave and surface dwelling individuals first appear during embryonic development. We hypothesized that antennal elaboration, as well as eye reduction and pigment loss, would be apparent during embryonic development. We found that differences in pigmentation, eye …


Foraging Distance Of The Argentine Ant In California Vineyards., Brian N. Hogg, Erik H. Nelson, James R. Hagler, Kent M. Daane Apr 2018

Foraging Distance Of The Argentine Ant In California Vineyards., Brian N. Hogg, Erik H. Nelson, James R. Hagler, Kent M. Daane

Natural Sciences and Mathematics | Faculty Scholarship

Argentine ants, Linepithema humile (Mayr) (Hymenoptera: Formicidae), form mutualisms with hemipteran pests in crop systems. In vineyards, they feed on honeydew produced by mealybugs and soft scales, which they tend and protect from natural enemies. Few options for controlling Argentine ants are available; one of the more effective approaches is to use liquid baits containing a low dose of an insecticide. Knowledge of ant foraging patterns is required to estimate how many bait stations to deploy per unit area. To measure how far ants move liquid bait in vineyards, we placed bait stations containing sugar water and a protein marker …


Mutations Of Conserved Non-Coding Elements Of Pitx2 In Patients With Ocular Dysgenesis And Developmental Glaucoma., Meredith E. Protas, Eric Weh, Tim Footz, Jay Kasberger, Scott C. Baraban, Alex V. Levin, L. Jay Katz, Robert Ritch, Michael A. Walter, Elena V. Semina, Douglas B. Gould Sep 2017

Mutations Of Conserved Non-Coding Elements Of Pitx2 In Patients With Ocular Dysgenesis And Developmental Glaucoma., Meredith E. Protas, Eric Weh, Tim Footz, Jay Kasberger, Scott C. Baraban, Alex V. Levin, L. Jay Katz, Robert Ritch, Michael A. Walter, Elena V. Semina, Douglas B. Gould

Natural Sciences and Mathematics | Faculty Scholarship

Mutations in FOXC1 and PITX2 constitute the most common causes of ocular anterior segment dysgenesis (ASD), and confer a high risk for secondary glaucoma. The genetic causes underlying ASD in approximately half of patients remain unknown, despite many of them being screened by whole exome sequencing. Here, we performed whole genome sequencing on DNA from two affected individuals from a family with dominantly inherited ASD and glaucoma to identify a 748-kb deletion in a gene desert that contains conserved putative PITX2 regulatory elements. We used CRISPR/Cas9 to delete the orthologous region in zebrafish in order to test the pathogenicity of …


Another Look At Pyrroloiminoquinone Alkaloids-Perspectives On Their Therapeutic Potential From Known Structures And Semisynthetic Analogues., Sheng Lin, Erin P. Mccauley, Nicholas Lorig-Roach, Karen Tenney, Cassandra N. Naphen, Ai-Mei Yang, Tyler A. Johnson, Thalia Hernadez, Ramandeep Rattan, Frederick A. Valeriote, Phillip Crews Mar 2017

Another Look At Pyrroloiminoquinone Alkaloids-Perspectives On Their Therapeutic Potential From Known Structures And Semisynthetic Analogues., Sheng Lin, Erin P. Mccauley, Nicholas Lorig-Roach, Karen Tenney, Cassandra N. Naphen, Ai-Mei Yang, Tyler A. Johnson, Thalia Hernadez, Ramandeep Rattan, Frederick A. Valeriote, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

This study began with the goal of identifying constituents from Zyzzya fuliginosa extracts that showed selectivity in our primary cytotoxicity screen against the PANC-1 tumor cell line. During the course of this project, which focused on six Z. fuliginosa samples collected from various regions of the Indo-Pacific, known compounds were obtained consisting of nine makaluvamine and three damirone analogues. Four new acetylated derivatives were also prepared. High-accuracy electrospray ionization mass spectrometry (HAESI-MS) m/z ions produced through MS2 runs were obtained and interpreted to provide a rapid way for dereplicating isomers containing a pyrrolo[4,3,2-de]quinoline core. In vitro human pancreas/duct epithelioid …


A Potent Antimalarial Benzoxaborole Targets A Plasmodium Falciparum Cleavage And Polyadenylation Specificity Factor Homologue., Ebere Sonoiki, Caroline L. Ng, Marcus C. S. Lee, Denghui Guo, Yong-Kang Zhang, Yasheen Zhou, M. R. K. Alley, Vida Ahyong, Laura M. Sanz, Maria Jose Lafuente-Monasterio, Chen Dong, Patrick G. Schupp, Jiri Gut, Jenny Legac, Roland A. Cooper, Francisco-Javier Gamo, Joseph Derisi, Yvonne R. Freund, David A. Fidock, Philip J. Rosenthal Mar 2017

A Potent Antimalarial Benzoxaborole Targets A Plasmodium Falciparum Cleavage And Polyadenylation Specificity Factor Homologue., Ebere Sonoiki, Caroline L. Ng, Marcus C. S. Lee, Denghui Guo, Yong-Kang Zhang, Yasheen Zhou, M. R. K. Alley, Vida Ahyong, Laura M. Sanz, Maria Jose Lafuente-Monasterio, Chen Dong, Patrick G. Schupp, Jiri Gut, Jenny Legac, Roland A. Cooper, Francisco-Javier Gamo, Joseph Derisi, Yvonne R. Freund, David A. Fidock, Philip J. Rosenthal

Natural Sciences and Mathematics | Faculty Scholarship

Benzoxaboroles are effective against bacterial, fungal and protozoan pathogens. We report potent activity of the benzoxaborole AN3661 against Plasmodium falciparum laboratory-adapted strains (mean IC50 32 nM), Ugandan field isolates (mean ex vivo IC50 64 nM), and murine P. berghei and P. falciparum infections (day 4 ED90 0.34 and 0.57 mg kg-1, respectively). Multiple P. falciparum lines selected in vitro for resistance to AN3661 harboured point mutations in pfcpsf3, which encodes a homologue of mammalian cleavage and polyadenylation specificity factor subunit 3 (CPSF-73 or CPSF3). CRISPR-Cas9-mediated introduction of pfcpsf3 mutations into parental lines recapitulated AN3661 resistance. PfCPSF3 homology models placed these …


Chemical Activation Of A Food Deprivation Signal Extends Lifespan., Mark Lucanic, Theo Garrett, Ivan Yu, Fernando Calahorro, Azar Asadi Shahmirzadi, Aaron Miller, Matthew S Gill, Robert E. Hughes, Lindy Holden-Dye, Gordon J. Lithgow Oct 2016

Chemical Activation Of A Food Deprivation Signal Extends Lifespan., Mark Lucanic, Theo Garrett, Ivan Yu, Fernando Calahorro, Azar Asadi Shahmirzadi, Aaron Miller, Matthew S Gill, Robert E. Hughes, Lindy Holden-Dye, Gordon J. Lithgow

Natural Sciences and Mathematics | Student Professional Publications

Model organisms subject to dietary restriction (DR) generally live longer. Accompanying this lifespan extension are improvements in overall health, based on multiple metrics. This indicates that pharmacological treatments that mimic the effects of DR could improve health in humans. To find new chemical structures that extend lifespan, we screened 30 000 synthetic, diverse drug-like chemicals in Caenorhabditis elegans and identified several structurally related compounds that acted through DR mechanisms. The most potent of these NP1 impinges upon a food perception pathway by promoting glutamate signaling in the pharynx. This results in the overriding of a GPCR pathway involved in the …


Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic And May Be Superior To Traditional Tinctures For Treating Inflammatory Disorders., Tyler A. Johnson, Johann Sohn, Wayne D Inman, Leonard F. Bjeldanes, Keith Rayburn Jan 2013

Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic And May Be Superior To Traditional Tinctures For Treating Inflammatory Disorders., Tyler A. Johnson, Johann Sohn, Wayne D Inman, Leonard F. Bjeldanes, Keith Rayburn

Natural Sciences and Mathematics | Faculty Scholarship

Extracts of four plant portions (roots, stems, leaves and flowers) of Urtica dioica (the stinging nettle) were prepared using accelerated solvent extraction (ASE) involving water, hexanes, methanol and dichloromethane. The extracts were evaluated for their anti-inflammatory and cytotoxic activities in an NF-κB luciferase and MTT assay using macrophage immune (RAW264.7) cells. A standardized commercial ethanol extract of nettle leaves was also evaluated. The methanolic extract of the flowering portions displayed significant anti-inflammatory activity on par with a standard compound celastrol (1) but were moderately cytotoxic. Alternatively, the polar extracts (water, methanol, ethanol) of the roots, stems and leaves displayed moderate …


Myxobacteria Versus Sponge-Derived Alkaloids: The Bengamide Family Identified As Potent Immune Modulating Agents By Scrutiny Of Lc-Ms/Elsd Libraries., Tyler A. Johnson, Johann Sohn, Yvette M. Vaske, Kimberly N. White, Tanya L. Cohen, Helene C. Vervoort, Karen Tenney, Frederick A. Valeriote, Leonard F. Bjeldanes, Phillip Crews Jul 2012

Myxobacteria Versus Sponge-Derived Alkaloids: The Bengamide Family Identified As Potent Immune Modulating Agents By Scrutiny Of Lc-Ms/Elsd Libraries., Tyler A. Johnson, Johann Sohn, Yvette M. Vaske, Kimberly N. White, Tanya L. Cohen, Helene C. Vervoort, Karen Tenney, Frederick A. Valeriote, Leonard F. Bjeldanes, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

A nuclear factor-κB (NF-κB) luciferase assay has been employed to identify the bengamides, previously known for their anti-tumor activity, as a new class of immune modulators. A unique element of this study was that the bengamide analogs were isolated from two disparate sources, Myxococcus virescens (bacterium) and Jaspis coriacea (sponge). Comparative LC-MS/ELSD and NMR analysis facilitated the isolation of M. viriscens derived samples of bengamide E (8) and two congeners, bengamide E' (13) and F' (14) each isolated as an insperable mixture of diastereomers. Additional compounds drawn from the UC, Santa Cruz repository allowed expansion of the structure activity relationship …


Glycosylation Of Human Cyclooxygenase-2 (Cox-2) Decreases The Efficacy Of Certain Cox-2 Inhibitors., Mary B. Sevigny, Kamara Graham, Esmeralda Ponce, Maggie Louie, Kylie Mitchell Apr 2012

Glycosylation Of Human Cyclooxygenase-2 (Cox-2) Decreases The Efficacy Of Certain Cox-2 Inhibitors., Mary B. Sevigny, Kamara Graham, Esmeralda Ponce, Maggie Louie, Kylie Mitchell

Natural Sciences and Mathematics | Faculty Scholarship

Prostanoids play an important role in a variety of physiological and pathophysiological processes including inflammation and cancer. The rate-limiting step in the prostanoid biosynthesis pathway is catalyzed by cyclooxygenase-2 (COX-2). COX-2 exists as two glycoforms, 72 and 74 kDa, the latter resulting from an additional glycosylation at Asn(580). In this study, Asn(580) was mutated, and the mutant and wild-type COX-2 genes were expressed in COS-1 cells to determine how glycosylation affects the inhibition of COX-2 activity by aspirin, flurbiprofen, ibuprofen, celecoxib, and etoricoxib. Results indicate that certain inhibitors were 2-5 times more effective at inhibiting COX-2 activity when the glycosylation …


Dimerization And Heme Binding Are Conserved In Amphibian And Starfish Homologues Of The Microrna Processing Protein Dgcr8., Rachel Senturia, Arthur Laganowsky, Ian Barr, Brooke D. Scheidemantle, Feng Guo Jan 2012

Dimerization And Heme Binding Are Conserved In Amphibian And Starfish Homologues Of The Microrna Processing Protein Dgcr8., Rachel Senturia, Arthur Laganowsky, Ian Barr, Brooke D. Scheidemantle, Feng Guo

Natural Sciences and Mathematics | Faculty Scholarship

Human DiGeorge Critical Region 8 (DGCR8) is an essential microRNA (miRNA) processing factor that is activated via direct interaction with Fe(III) heme. In order for DGCR8 to bind heme, it must dimerize using a dimerization domain embedded within its heme-binding domain (HBD). We previously reported a crystal structure of the dimerization domain from human DGCR8, which demonstrated how dimerization results in the formation of a surface important for association with heme. Here, in an attempt to crystallize the HBD, we search for DGCR8 homologues and show that DGCR8 from Patiria miniata (bat star) also binds heme. The extinction coefficients (ε) …


Digeorge Critical Region 8 (Dgcr8) Is A Double-Cysteine-Ligated Heme Protein., Ian Barr, Aaron T. Smith, Rachel Senturia, Yanqiu Chen, Brooke D. Scheidemantle, Judith N. Burstyn, Feng Guo May 2011

Digeorge Critical Region 8 (Dgcr8) Is A Double-Cysteine-Ligated Heme Protein., Ian Barr, Aaron T. Smith, Rachel Senturia, Yanqiu Chen, Brooke D. Scheidemantle, Judith N. Burstyn, Feng Guo

Natural Sciences and Mathematics | Faculty Scholarship

All known heme-thiolate proteins ligate the heme iron using one cysteine side chain. We previously found that DiGeorge Critical Region 8 (DGCR8), an essential microRNA processing factor, associates with heme of unknown redox state when overexpressed in Escherichia coli. On the basis of the similarity of the 450-nm Soret absorption peak of the DGCR8-heme complex to that of cytochrome P450 containing ferrous heme with CO bound, we identified cysteine 352 as a probable axial ligand in DGCR8. Here we further characterize the DGCR8-heme interaction using biochemical and spectroscopic methods. The DGCR8-heme complex is highly stable, with a half-life exceeding 4 …


The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B. Jekabsons, Tyler A. Johnson, Koneni V. Sashidhara, Phillip Crews, Dale G. Nagle, Yu-Dong Zhou Aug 2010

The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B. Jekabsons, Tyler A. Johnson, Koneni V. Sashidhara, Phillip Crews, Dale G. Nagle, Yu-Dong Zhou

Natural Sciences and Mathematics | Faculty Scholarship

A natural product chemistry-based approach was applied to discover small-molecule inhibitors of hypoxia-inducible factor-1 (HIF-1). A Petrosaspongia mycofijiensis marine sponge extract yielded mycothiazole (1), a solid tumor selective compound with no known mechanism for its cell line-dependent cytotoxic activity. Compound 1 inhibited hypoxic HIF-1 signaling in tumor cells (IC(50) 1nM) that correlated with the suppression of hypoxia-stimulated tumor angiogenesis in vitro. However, 1 exhibited pronounced neurotoxicity in vitro. Mechanistic studies revealed that 1 selectively suppresses mitochondrial respiration at complex I (NADH-ubiquinone oxidoreductase). Unlike rotenone, MPP(+), annonaceous acetogenins, piericidin A, and other complex I inhibitors, mycothiazole is a mixed polyketide/peptide-derived compound …


Development And Validation Of A Rapid Method For The Detection Of Latrunculol A In Plasma., Jiajiu Shaw, Frederick A. Valeriote, Joseph Media, Tyler A. Johnson, Taro Amagata, Karen Tenney, Phillip Crews Mar 2010

Development And Validation Of A Rapid Method For The Detection Of Latrunculol A In Plasma., Jiajiu Shaw, Frederick A. Valeriote, Joseph Media, Tyler A. Johnson, Taro Amagata, Karen Tenney, Phillip Crews

Natural Sciences and Mathematics | Faculty Scholarship

Latrunculol A is a recently discovered 6,7-dihydroxy analog of the potent actin inhibitor latrunculin A. Latrunculol A has exhibited greater cytotoxicity than latrunculin A against both murine and human colon tumor cell lines in vitro. Currently, there are no reports regarding the bioavailability of latrunculol A in vivo. This study was undertaken as a prelude to pharmacokinetic assessments and it is the first work where bioavailability of latrunculol A was studied. In the present work, a simple plasma preparation and a rapid HPLC method have been developed. Mouse plasma containing latrunculol A was first treated by acetonitrile and then centrifuged …


Mass Stranding Of Marine Birds Caused By A Surfactant-Producing Red Tide., David A. Jessup, Melissa A. Miller, John P. Ryan, Hannah M. Nevins, Heather A. Kerkering, Abdou Mekebri, David B. Crane, Tyler A. Johnson, Raphael M. Kudela Jan 2009

Mass Stranding Of Marine Birds Caused By A Surfactant-Producing Red Tide., David A. Jessup, Melissa A. Miller, John P. Ryan, Hannah M. Nevins, Heather A. Kerkering, Abdou Mekebri, David B. Crane, Tyler A. Johnson, Raphael M. Kudela

Natural Sciences and Mathematics | Faculty Scholarship

In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone …


Glycosylation Regulates Turnover Of Cyclooxygenase-2., Mary B. Sevigny, Chai-Fei Li, Monika Alas, Millie Hughes-Fulford Dec 2006

Glycosylation Regulates Turnover Of Cyclooxygenase-2., Mary B. Sevigny, Chai-Fei Li, Monika Alas, Millie Hughes-Fulford

Natural Sciences and Mathematics | Faculty Scholarship

Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step in the prostanoid biosynthesis pathway, converting arachidonic acid into prostaglandin H(2). COX-2 exists as 72 and 74kDa glycoforms, the latter resulting from an additional oligosaccharide chain at residue Asn(580). In this study, Asn(580) was mutated to determine the biological significance of this variable glycosylation. COS-1 cells transfected with the mutant gene were unable to express the 74kDa glycoform and were found to accumulate more COX-2 protein and have five times greater COX-2 activity than cells expressing both glycoforms. Thus, COX-2 turnover appears to depend upon glycosylation of the 72kDa glycoform.