Biotechnology Commons^™

Tumor Suppression By Cell Competition Through Regulation Of The Hippo Pathway, Chiao-Lin Chen, Molly C. Schroeder, Madhuri Kango-Singh, Chunyao Tao, Georg Halder

Biology Faculty Publications

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib− cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does …

Out Of Sight, But Not Out Of Mind: A Look At Nanoparticles In The Marine Environment, Evan Ward, John J. Doyle

Wrack Lines

Nanoparticles exist in many products used by humans, such as sunscreens. medications, cosmetics, paints and electronics. But what is the effect of these tiny particles on the ocean or estuarine environment when the sunscreen washes off? This article looks at that question and at shellfish in particular. Evan Ward and John Doyle are marine scientists at UConn.

Isolation And Characterization Of Galactinol Synthases From Hybrid Poplar, Faride Unda, Thomas Canam, Lindsay Preston, Shawn D. Mansfield

Faculty Research & Creative Activity

The raffinose family of oligosaccharides (RFOs) serve as transport carbohydrates in the phloem, storage compounds in sink tissues, and putative biological agents to combat both abiotic and biotic stress in several plant species. To investigate further the functional roles of this class of compounds in trees, two cDNAs encoding galactinol synthase (GolS, EC 2.4.1.123), which catalyses the first step in the biosynthesis of RFOs, were identified and cloned from hybrid poplar (Populus alba3grandidentata). Phylogenetic analyses of the Populus GolS isoforms with other known GolS proteins suggested a putative role for these enzymes during biotic or abiotic stress in hybrid poplar. …

Tgd1, -2, And -3 Proteins Involved In Lipid Trafficking Form Atp-Binding Cassette (Abc) Transporter With Multiple Substrate-Binding Proteins, Rebecca Roston, Jinpeng Gao, Monika W. Murcha, James Whelan, Christoph Benning

Department of Biochemistry: Faculty Publications

Background: ATP-binding cassette transporters exist in all life forms and usually require only one substrate-binding domain.

Results: The TRIGALACTOSYLDIACYLGLYCEROL (TGD) complex contains 8–12 substrate-binding proteins.

Conclusion: Multiple substrate-binding proteins may be needed by the TGD complex to enhance its putative lipid transport activity.

Significance: Knowing the subunit stoichiometry of the TGD complex furthers understanding of lipid transfer between chloroplast membranes.

Isolation And Characterization Of Galactinol Synthases From Hybrid Poplar, Faride Unda, Thomas Canam, Lindsay Preston, Shawn Mansfield

Faculty Research & Creative Activity

The raffinose family of oligosaccharides (RFOs) serve as transport carbohydrates in the phloem, storage compounds in sink tissues, and putative biological agents to combat both abiotic and biotic stress in several plant species. To investigate further the functional roles of this class of compounds in trees, two cDNAs encoding galactinol synthase (GolS, EC 2.4.1.123), which catalyses the first step in the biosynthesis of RFOs, were identified and cloned from hybrid poplar (Populus alba3grandidentata). Phylogenetic analyses of the Populus GolS isoforms with other known GolS proteins suggested a putative role for these enzymes during biotic or abiotic stress in hybrid poplar. …

Nutraceutical Antioxidants And Their Therapeutic Potential In Neurodegeneration, Erika Kristine Ross

Electronic Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease that affects motor neurons of the brain and spinal cord. Many studies indicate that mitochondrial oxidative stress (MOS) is a principal mechanism underlying the pathophysiology of this and other devastating neurodegenerative diseases. Here, we investigated a unique whey protein supplement (Immunocal®) to determine its neuroprotective efficacy in several in vitro models of MOS and in an in vivo mouse model of ALS. This non-denatured whey supplement contains cystine which is an oxidized form of cysteine, an essential precursor for synthesis of the endogenous antioxidant, glutathione (GSH). In primary cultured rat cerebellar …

A Novel Link Between Akt1 And Twist1 In Ovarian Tumor Cell Motility And Invasiveness, Nirav Shah

Electronic Theses and Dissertations

Ovarian cancer results in more deaths per year than any other cancer of the female reproductive system. The low survival rate is partly due to the lack of early detection and the susceptibility to relapse. The AKT serine threonine kinase plays a pivotal role in hallmark cellular processes for the progression of ovarian cancer, including tumor cell growth and migration. Therapeutic targeting of pan-AKT has been problematic, in part due to feedback mechanisms and crosstalk with other pathways. The hypothesis for this study is that AKT 1, -2 and -3 isoforms may have different roles and regulate cell processes in …

Genome, Functional Gene Annotation, And Nuclear Transformation Of The Heterokont Oleaginous Alga Nannochloropsis Oceanica Ccmp1779, Astrid Vieler, Guangxi Wu, Chia-Hong Tsai, Blair Bullard, Adam J. Cornish, Christopher Harvey, Ida-Barbara Reca, Chelsea Thornburg, Rujira Achawanantakun, Christopher J. Buehl, Michael S. Campbell, David Cavalier, Kevin L. Childs, Teresa J. Clark, Rahul Deshpande, Erika Erickson, Ann Armenia Ferguson, Witawas Handee, Que Kong, Xiaobo Li, Bensheng Liu, Steven Lundback, Cheng Peng, Rebecca Roston, Michigan State University, Jeffrey P. Simpson, Allan Terbush, Jaruswan Warakanont, Simone Zäuner, Eva M. Farre, Eric L. Hegg, Ning Jiang, Min-Hao Kuo, Yan Lu, Krishna K. Niyogi, John Ohlrogge, Katherine W. Osteryoung, Yair Shachar-Hill, Barbara B. Sears, Yanni Sun, Hideki Takahashi, Mark Yandell, Shin-Han Shiu, Christoph Benning

Department of Biochemistry: Faculty Publications

Unicellular marine algae have promise for providing sustainable and scalable biofuel feedstocks, although no single species has emerged as a preferred organism. Moreover, adequate molecular and genetic resources prerequisite for the rational engineering of marine algal feedstocks are lacking for most candidate species. Heterokonts of the genus Nannochloropsis naturally have high cellular oil content and are already in use for industrial production of high-value lipid products. First success in applying reverse genetics by targeted gene replacement makes Nannochloropsis oceanica an attractive model to investigate the cell and molecular biology and biochemistry of this fascinating organism group. Here we present the …

Small But Crucial: The Novel Small Heat Shock Protein Hsp21 Mediates Stress Adaptation And Virulence In Candida Albicans, Francois L. Mayer, Duncan Wilson, Ilse D. Jacobsen, Pedro Miramón, Silvia Slesiona, Iryna Bohovych, Alistair J.P. Brown, Bernhard Hube

Department of Biochemistry: Faculty Publications

Small heat shock proteins (sHsps) have multiple cellular functions. However, the biological function of sHsps in pathogenic microorganisms is largely unknown. In the present study we identified and characterized the novel sHsp Hsp21 of the human fungal pathogen Candida albicans. Using a reverse genetics approach we demonstrate the importance of Hsp21 for resistance of C. albicans to specific stresses, including thermal and oxidative stress. Furthermore, a hsp21∆/∆ mutant was defective in invasive growth and formed significantly shorter filaments compared to the wild type under various filamentinducing conditions. Although adhesion to and invasion into human-derived endothelial and oral epithelial cells …

Oligomerization Of Heme O Synthase In Cytochrome Oxidase Biogenesis Is Mediated By Cytochrome Oxidase Assembly Factor Coa2, Oleh Khalimonchuk, Hyung Kim, Talina Watts, Xochitl Perez-Martinez, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The synthesis of the heme a cofactor used in cytochrome c

oxidase (CcO) is dependent on the sequential action of heme o

synthase (Cox10) and heme a synthase (Cox15). The active state of

Cox10 appears to be a homo-oligomeric complex,andformation of

this complex is dependent on the newly synthesized CcO subunit

Cox1 and the presence of an early Cox1 assembly intermediate.

Cox10 multimerization is triggered by progression of Cox1 from

the early assembly intermediate todownstreamintermediates.The

CcOassembly factor Coa2 appears important in coupling the presence

of newly synthesized Cox1 to Cox10 oligomerization. Cells

lacking Coa2 are impaired in Cox10 complex formation …

Selective Oma1 Protease-Mediated Proteolysis Of Cox1 Subunit Of Cytochrome Oxidase In Assembly Mutants, Oleh Khalimonchuk, Mi-Young Jeong, Talina Watts, Elliott Ferris, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Background: Yeast lacking Coa2 are deficient in cytochrome c oxidase due to Cox1 degradation.

Results: Oma1 mediates Cox1 degradation in coa2∆ cells but not other mutants stalled in oxidase biogenesis.

Conclusion: Impaired hemylation of Cox1 in coa2∆ cells leads to misfolding and facile degradation by Oma1.

Significance: Oma1 functions in quality control of cytochrome oxidase assembly.

Bio-Logic Builder: A Non-Technical Tool For Building Dynamical, Qualitative Models, Tomáš Helikar, Bryan Kowal, Alex Madrahimov, Manish Shrestha, Jay Pedersen, Kahani Limbu, Ishwor Thapa, Thaine Rowley, Rahul Satalkar, Naomi Kochi, John Konvalina, Jim A. Rogers

Department of Biochemistry: Faculty Publications

Computational modeling of biological processes is a promising tool in biomedical research. While a large part of its potential lies in the ability to integrate it with laboratory research, modeling currently generally requires a high degree of training in mathematics and/or computer science. To help address this issue, we have developed a web-based tool, Bio- Logic Builder, that enables laboratory scientists to define mathematical representations (based on a discrete formalism) of biological regulatory mechanisms in a modular and non-technical fashion. As part of the user interface, generalized ‘‘biologic’’ modules have been defined to provide users with the building blocks for …

Ergodic Sets As Cell Phenotype Of Budding Yeast Cell Cycle, Robert G. Todd, Tomáš Helikar

Department of Biochemistry: Faculty Publications

It has been suggested that irreducible sets of states in Probabilistic Boolean Networks correspond to cellular phenotype. In this study, we identify such sets of states for each phase of the budding yeast cell cycle. We find that these ‘‘ergodic sets’’ underly the cyclin activity levels during each phase of the cell cycle. Our results compare to the observations made in several laboratory experiments as well as the results of differential equation models. Dynamical studies of this model: (i) indicate that under stochastic external signals the continuous oscillating waves of cyclin activity and the opposing waves of CKIs …

The Cell Collective: Toward An Open And Collaborative Approach To Systems Biology, Tomáš Helikar, Bryan Kowal, Sean Mcclenathan, Mitchell Bruckner, Thaine Rowley, Alex Madrahimov, Ben Wicks, Manish Shrestha, Kahani Limbu, Jim A. Rogers

Department of Biochemistry: Faculty Publications

Background: Despite decades of new discoveries in biomedical research, the overwhelming complexity of cells has been a significant barrier to a fundamental understanding of how cells work as a whole. As such, the holistic study of biochemical pathways requires computer modeling. Due to the complexity of cells, it is not feasible for one person or group to model the cell in its entirety.

Results: The Cell Collective is a platform that allows the world-wide scientific community to create these models collectively. Its interface enables users to build and use models without specifying any mathematical equations or computer code - addressing …

A Framework Genetic Map For Miscanthus Sinensis From Rnaseq-Based Markers Shows Recent Tetraploidy, Kankshita Swaminathan, Won Byoung Chae, Therese Mitros, Kranthi Varala, Liang Xie, Adam Barling, Katarzyna Glowacka, Megan Hall, Stanislaw Jezowski, Ray Ming, Matthew Hudson, John A. Juvik, Daniel S. Rokhsar, Stephen P. Moose

Department of Biochemistry: Faculty Publications

Background: Miscanthus (subtribe Saccharinae, tribe Andropogoneae, family Poaceae) is a genus of temperate perennial C4 grasses whose high biomass production makes it, along with its close relatives sugarcane and sorghum, attractive as a biofuel feedstock. The base chromosome number of Miscanthus (x = 19) is different from that of other Saccharinae and approximately twice that of the related Sorghum bicolor (x = 10), suggesting largescale duplications may have occurred in recent ancestors of Miscanthus. Owing to the complexity of the Miscanthus genome and the complications of self-incompatibility, a complete genetic map with a high density of markers has not …

Glutaredoxin 1 Protects Dopaminergic Cells By Increased Protein Glutathionylation In Experimental Parkinson's Disease, Humberto Rodriguez-Rocha, Aracely Garcia Garcia, Laura Zavala-Flores, Sumin Li, Nandakumar Madayiputhiya, Rodrigo Franco

Department of Biochemistry: Faculty Publications

Aims: Chronic exposure to environmental toxicants, such as paraquat, has been suggested as a risk factor for Parkinson's disease (PD). Although dopaminergic cell death in PD is associated with oxidative damage, the molecular mechanisms involved remain elusive. Glutaredoxins (GRXs) utilize the reducing power of glutathione to modulate redox-dependent signaling pathways by protein glutathionylation. We aimed to determine the role of GRX1 and protein glutathionylation in dopaminergic cell death. Results: In dopaminergic cells, toxicity induced by paraquat or 6-hydroxydopamine (6-OHDA) was inhibited by GRX1 overexpression, while its knock-down sensitized cells to paraquat-induced cell death. Dopaminergic cell death was paralleled by protein …

Late-Stage Maturation Of The Rieske Fe/S Protein: Mzm1 Stabilizes Rip1 But Does Not Facilitate Its Translocation By The Aaa Atpase Bcs1, Tie-Zhong Cui, Pamela M. Smith, Jennifer L. Fox, Oleh Khalimonchuk, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The final step in the assembly of the ubiquinol-cytochrome c reductase or bc₁ complex involves the insertion of the Rieske Fe/S cluster protein, Rip1. Maturation of Rip1 occurs within the mitochondrial matrix prior to its translocation across the inner membrane (IM) in a process mediated by the Bcs1 ATPase and subsequent insertion into the bc₁ complex. Here we show that the matrix protein Mzm1 functions as a Rip1 chaperone, stabilizing Rip1 prior to the translocation step. In the absence of Mzm1, Rip1 is prone to either proteolytic degradation or temperature-induced aggregation. A series of Rip1 truncations were engineered …

Mononuclear Phagocyte Intercellular Crosstalk Facilitates Transmission Of Cell-Targeted Nanoformulated Antiretroviral Drugs To Human Brain Endothelial Cells, Georgette D. Kanmogne, Sangya Singh, Upal Roy, Xinming Liu, Joellyn Mcmillan, Santhi Gorantla, Shantanu Balkundi, Nathan Smith, Yazen Alnouti, Nagsen Gautam, You Zhou, Larisa Poluektova, Alexander Kabanov, Tatiana Bronich, Howard Gendelman

Nebraska Center for Biotechnology: Faculty and Staff Publications

Despite the successes of antiretroviral therapy (ART), HIV-associated neurocognitive disorders remain prevalent in infected people. This is due, in part, to incomplete ART penetration across the blood–brain barrier (BBB) and lymph nodes and to the establishment of viral sanctuaries within the central nervous system. In efforts to improve ART delivery, our laboratories developed a macrophage-carriage system for nanoformulated crystalline ART (nanoART) (atazanavir, ritonavir, indinavir, and efavirenz). We demonstrate that nanoART transfer from mononuclear phagocytes (MP) to human brain microvascular endothelial cells (HBMEC) can be realized through cell-to-cell contacts, which can facilitate drug passage across the BBB. Coculturing of donor MP …

Wall_1.6 — Acknowledgements, Allison Marsh

Section 1: Introduction

No abstract provided.

Proline Dehydrogenase Is Essential For Proline Protection Against Hydrogen Peroxide Induced Cell Death, Sathish Kumar Natarajan, Weidong Zhu, Xinwen Liang, Lu Zhang, Andrew Demers, Matthew C. Zimmerman, Melanie A. Simpson, Donald F. Becker

Department of Biochemistry: Faculty Publications

Proline metabolism has an underlying role in apoptotic signaling that impacts tumorigenesis. Proline is oxidized to glutamate in the mitochondria with the rate limiting step catalyzed by proline dehydrogenase (PRODH). PRODH expression is inducible by p53 leading to increased proline oxidation, reactive oxygen species (ROS) formation, and induction of apoptosis. Paradoxical to its role in apoptosis, proline also protects cells against oxidative stress. Here we explore the mechanism of proline protection against hydrogen peroxide stress in melanoma WM35 cells. Treatment of WM35 cells with proline significantly increased cell viability, diminished oxidative damage of cellular lipids and proteins, and retained ATP …