Biotechnology Commons^™

Role Of Apoptosis-Inducing Factor, Proline Dehydrogenase, And Nadph Oxidase In Apoptosis And Oxidative Stress, Sathish Kumar Natarajan, Donald F. Becker

Department of Biochemistry: Faculty Publications

Flavoproteins catalyze a variety of reactions utilizing flavin mononucleotide or flavin adenine dinucleotide as cofactors. The oxidoreductase properties of flavoenzymes implicate them in redox homeostasis, oxidative stress, and various cellular processes, including programmed cell death. Here we explore three critical flavoproteins involved in apoptosis and redox signaling, ie, apoptosis-inducing factor (AIF), proline dehydrogenase, and NADPH oxidase. These proteins have diverse biochemical functions and influence apoptotic signaling by unique mechanisms. The role of AIF in apoptotic signaling is two-fold, with AIF changing intracellular location from the inner mitochondrial membrane space to the nucleus upon exposure of cells to apoptotic stimuli. In …

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 …

Substrate Channeling In Proline Metabolism, Benjamin W. Arentson, Nikhilesh Sanyal, Donald F. Becker

Department of Biochemistry: Faculty Publications

Proline metabolism is an important pathway that has relevance in several cellular functions such as redox balance, apoptosis, and cell survival. Results from different groups have indicated that substrate channeling of proline metabolic intermediates may be a critical mechanism. One intermediate is pyrroline-5-carboxylate (P5C), which upon hydrolysis opens to glutamic semialdehyde (GSA). Recent structural and kinetic evidence indicate substrate channeling of P5C/ GSA occurs in the proline catabolic pathway between the proline dehydrogenase and P5C dehydrogenase active sites of bifunctional proline utilization A (PutA). Substrate channeling in PutA is proposed to facilitate the hydrolysis of P5C to GSA which is …

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 …

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 …

Boron Stress Activates The General Amino Acid Control Mechanism And Inhibits Protein Synthesis, Irem Uluisik, Alaattin Kaya, Dmitri E. Fomenko, Huseyin C. Karakaya, Bradley A. Carlson, Vadim N. Gladyshev, Ahmet Koc

Department of Biochemistry: Faculty Publications

Boron is an essential micronutrient for plants, and it is beneficial for animals. However, at high concentrations boron is toxic to cells although the mechanism of this toxicity is not known. Atr1 has recently been identified as a boron efflux pump whose expression is upregulated in response to boron treatment. Here, we found that the expression of ATR1 is associated with expression of genes involved in amino acid biosynthesis. These mechanisms are strictly controlled by the transcription factor Gcn4 in response to boron treatment. Further analyses have shown that boron impaired protein synthesis by promoting phosphorylation of eIF2α in a …

Iron Insufficiency Compromises Motor Neurons And Their Mitochondrial Function In Irp2-Null Mice, Suh Young Jeong, Daniel R. Crooks, Hayden Wilson-Ollivierre, Manik C. Ghosh, Rachid Sougrat, Jaekwon Lee, Sharon Cooperman, James B. Mitchell, Carole Beaumont, Tracey A. Rouault

Department of Biochemistry: Faculty Publications

Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2), which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 …

Mne1 Is A Novel Component Of The Mitochondrial Splicing Apparatus Responsible For Processing Of A Cox1 Group I Intron In Yeast, Talina Watts, Oleh Khalimonchuk, Rachel Z. Wolf, Edward M. Turk, Georg Mohr, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Saccharomyces cerevisiae cells lacking Mne1 are deficient in

intron splicing in the gene encoding the Cox1 subunit of cytochrome

oxidase but contain wild-type levels of the bc1 complex.

Thus, Mne1 has no role in splicing of COB introns or expression

of the COB gene. Northern experiments suggest that splicing of

the COX1 aI5β intron is dependent on Mne1 in addition to the

previously known Mrs1, Mss116, Pet54, and Suv3 factors. Processing

of the aI5_ intron is similarly impaired in mne1∆ and

mrs1∆ cells and overexpression of Mrs1 partially restores the

respiratory function of mne1∆ cells. Mrs1 …

Hydrogen Peroxide Probes Directed To Different Cellular Compartments, Mikalai Malinouski, You Zhou, Vsevolod V. Belousov, Dolph L. Hatfield, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Background: Controlled generation and removal of hydrogen peroxide play important roles in cellular redox homeostasis and signaling. We used a hydrogen peroxide biosensor HyPer, targeted to different compartments, to examine these processes in mammalian cells.

Principal Findings: Reversible responses were observed to various redox perturbations and signaling events. HyPer expressed in HEK 293 cells was found to sense low micromolar levels of hydrogen peroxide. When targeted to various cellular compartments, HyPer occurred in the reduced state in the nucleus, cytosol, peroxisomes, mitochondrial intermembrane space and mitochondrial matrix, but low levels of the oxidized form of the biosensor were also observed …

Targeted Deletion Of The Mouse Mitoferrin1 Gene: From Anemia To Protoporphyria, Marie-Berengere Troadec, David Warner, Jared Wallace, Kirk Thomas, Gerald J. Spangrude, John Phillips, Oleh Khalimonchuk, Barry H. Paw, Diane Mcvey Ward, Jerry Kaplan

Department of Biochemistry: Faculty Publications

Mitoferrin1 is 1 of 2 homologous mitochondrial iron transporters and is required for mitochondrial iron delivery in developing erythroid cells. We show that total deletion of Mfrn1 in embryos leads to embryonic lethality. Selective deletion of Mfrn1 in adult hematopoietic tissues leads to severe anemia because of a deficit in erythroblast formation. Deletion of Mfrn1 in hepatocytes has no phenotype or biochemical effect under normal conditions. In the presence of increased porphyrin synthesis, however, deletion of Mfrn1 in hepatocytes results in a decreased ability to convert protoporphyrin IX into heme, leading to protoporphyria, cholestasis, and bridging cirrhosis. Our results show …

Reduced Utilization Of Selenium By Naked Mole Rats Due To A Specific Defect In Gpx1 Expression, Marina V. Kasaikina, Alexei V. Lobanov, Mikalai I. Malinouski, Byung Cheon Lee, Javier Seravalli, Dmitri E. Fomenko, Anton A. Turanov, Lydia Finney, Stefan Vogt, Thomas J. Park, Richard A. Miller, Dolph L. Hatfield, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Naked mole rat (MR) Heterocephalus glaber is a rodent model of delayed aging because of its unusually long life span (>28 years). It is also not known to develop cancer. In the current work, tissue imaging by x-ray fluorescence microscopy and direct analyses of trace elements revealed low levels of selenium in the MR liver and kidney, whereas MR and mouse brains had similar selenium levels. This effect was not explained by uniform selenium deficiency because methionine sulfoxide reductase activities were similar in mice and MR. However, glutathione peroxidase activity was an order of magnitude lower inMRliver and kidney …

A 4-Selenocysteine, 2-Selenocysteine Insertion Sequence (Secis) Element Methionine Sulfoxide Reductase From Metridium Senile Reveals A Non-Catalytic Function Of Selenocysteines, Byung Cheon Lee, Alexey V. Lobanov, Stefano M. Marino, Alaattin Kaya, Javier Seravalli, Dolph L. Hatfield, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Selenocysteine (Sec) residues occur in thiol oxidoreductase families, and functionally characterized selenoenzymes typically have a single Sec residue used directly for redox catalysis. However, how new Sec residues evolve and whether non-catalytic Sec residues exist in proteins is not known. Here, we computationally identified several genes with multiple Sec insertion sequence (SECIS) elements, one of which was a methionine-Rsulfoxide reductase (MsrB) homolog from Metridium senile that has four in-frame UGA codons and two nearly identical SECIS elements. One of the UGA codons corresponded to the conserved catalytic Sec or Cys in MsrBs, whereas the three other UGA codons evolved recently …

Escherichia Coli Thioredoxin-Like Protein Ybbn Contains An Atypical Tetratricopeptide Repeat Motif And Is A Negative Regulator Of Groel, Jiusheng Lin, Mark A. Wilson

Department of Biochemistry: Faculty Publications

Many proteins contain a thioredoxin (Trx)-like domain fused with one or more partner domains that diversify protein function by the modular construction of new molecules. The Escherichia coli protein YbbN is a Trx-like protein that contains a C-terminal domain with low homology to tetratricopeptide repeat motifs. YbbN has been proposed to act as a chaperone or co-chaperone that aids in heat stress response andDNAsynthesis. We report the crystal structure of YbbN, which is an elongated molecule with a mobile Trx domain and four atypical tetratricopeptide repeat motifs. The Trx domain lacks a canonical CXXC active site architecture and is not …

Defining A Relationship Between Dietary Fatty Acids And The Cytochrome P450 System In A Mouse Model Of Fatty Liver Disease, Monika Gonzalez, Whitney Sealls, Elliot D. Jesch, M. Julia Brosnan, Istvan Ladunga, Xinxin Ding, Paul N. Black, Concetta C. Dirusso

Department of Biochemistry: Faculty Publications

Liver-specific ablation of cytochrome P450 reductase in mice (LCN) results in hepatic steatosis that can progress to steatohepatitis characterized by inflammation and fibrosis. The specific cause of the fatty liver phenotype is poorly understood but is hypothesized to result from elevated expression of genes encoding fatty acid synthetic genes. Since expression of these genes is known to be suppressed by polyunsaturated fatty acids, we performed physiological and genomics studies to evaluate the effects of dietary linoleic and linolenic fatty acids (PUFA) or arachidonic and decosahexaenoic acids (HUFA) on the hepatic phenotypes of control and LCN mice by comparison with a …

Functional Diversification Of Thylakoidal Processing Peptidases In Arabidopsis Thaliana, Shih-Chi Hsu, Joshua K. Endow, Nicholas J. Ruppel, Rebecca Roston, Amy J. Baldwin, Kentaro Inoue

Department of Biochemistry: Faculty Publications

Thylakoidal processing peptidase (TPP) is responsible for removing amino-terminal thylakoid-transfer signals from several proteins in the thylakoid lumen. Three TPP isoforms are encoded by the nuclear genome of Arabidopsis thaliana. Previous studies showed that one of them termed plastidic type I signal peptidase 1 (Plsp1) was necessary for processing three thylakoidal proteins and one protein in the chloroplast envelope in vivo. The lack of Plsp1 resulted in seedling lethality, apparently due to disruption of proper thylakoid development. The physiological roles of the other two TPP homologs remain unknown. Here we show that the three A. thaliana TPP isoforms …

Enzymatic Defects Underlying Hereditary Glutamate Cysteine Ligase Deficiency Are Mitigated By Association Of The Catalytic And Regulatory Subunits, Melanie Neely Willis, Yilin Liu, Ekaterina I. Biterova, Melanie A. Simpson, Heejeong Kim, Jaekwon Lee, Joseph J. Barycki

Department of Biochemistry: Faculty Publications

Glutamate cysteine ligase (GCL) deficiency is a rare autosomal recessive trait that compromises

production of glutathione, a critical redox buffer and enzymatic cofactor. Patients have markedly

reduced levels of erythrocyte glutathione, leading to hemolytic anemia and in some cases,

impaired neurological function. Human glutamate cysteine ligase is a heterodimer comprised of a

catalytic (GCLC) and a regulatory subunit (GCLM), which catalyzes the initial rate limiting step

in glutathione production. Four clinical missense mutations have been identified within GCLC:

Arg127Cys, Pro158Leu, His370Leu, and Pro414Leu. Here, we have evaluated the impacts of

these mutations on enzymatic function in vivo and in vitro …

The Lyr Protein Mzm1 Functions In The Insertion Of The Rieske Fe/S Protein In Yeast Mitochondria, Aaron Atkinson, Pamela Smith, Jennifer L. Fox, Tie-Shong Cui, Oleh Khalimonchuk, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The assembly of the cytochrome bc1 complex in Saccharomyces cerevisiae is shown to be conditionally dependent on a novel factor, Mzm1. Cells lacking Mzm1 exhibit a modest bc₁ defect at 30°C, but the defect is exacerbated at elevated temperatures. Formation of bc₁ is stalled in mzm1 Δ cells at a late assembly intermediate lacking the Rieske iron-sulfur protein Rip1. Rip1 levels are markedly attenuated in mzm1 Δ cells at elevated temperatures. Respiratory growth can be restored in the mutant cells by the overexpression of the Rip1 subunit. Elevated levels of Mzm1 enhance the stabilization of Rip1 through …

Rpir Homologues May Link Staphylococcus Aureus Rnaiii Synthesis And Pentose Phosphate Pathway Regulation, Yefei Zhu, Nandakumar Madayiputhiya, Marat R. Sadykov, Nandakumar Madayiputhiya, Thanh T. Luong, Rosmarie Gaupp, Chia Y. Lee, Greg Somerville

Department of Biochemistry: Faculty Publications

Staphylococcus aureus is a medically important pathogen that synthesizes a wide range of virulence determinants. The synthesis of many staphylococcal virulence determinants is regulated in part by stress-induced changes in the activity of the tricarboxylic acid (TCA) cycle. One metabolic change associated with TCA cycle stress is an increased concentration of ribose, leading us to hypothesize that a pentose phosphate pathway (PPP)-responsive regulator mediates some of the TCA cycle-dependent regulatory effects. Using bioinformatics, we identified three potential ribose-responsive regulators that belong to the RpiR family of transcriptional regulators. To determine whether these RpiR homologues affect PPP activity and virulence determinant …

In Vivo Liver Endocytosis Followed By Purification Of Liver Cells By Liver Perfusion, Sandhya Gopalakrishnan, Edward N. Harris

Department of Biochemistry: Faculty Publications

The liver is the metabolic center of the mammalian body and serves as a filter for the blood. The basic architecture of the liver is illustrated in figure ¹ in which more than 85% of the liver mass is composed of hepatocytes and the remaining 15% of the cellular mass is composed of Kupffer cells (KCs), stellate cells (HSCs), and sinusoidal endothelial cells (SECs). SECs form the blood vessel walls within the liver and contain specialized morphology called fenestrae within in the cytoplasm. Fenestration of the cytoplasm is the appearance of holes (˜100 μm) within the cells so that the …

The Genomics Education Partnership: Successful Integration Of Research Into Laboratory Classes At A Diverse Group Of Undergraduate Institutions, Christopher D. Shaffer, Consuelo Alvarez, Cheryl Bailey, Daron Barnard, Satish Bhalla, Chitra Chandrasekaran, Vidya Chandrasekaran, Hui-Min Chung, Douglas R. Dorer, Chunguang Du, Todd T. Eckdahl, Jeff L. Poet, Donald Frohlich, Anya L. Goodman, Yuying Gossner, Charles Hauser, Laura L.M. Hoopes, Diana Johnson, Christopher J. Jones, Marian Kaehler, Nighat Kokan, Olga R. Kopp, Gary A. Kuleck, Gerard Mcneil, Robert Moss, Jennifer L. Myka, Alexis Nagengast, Robert Morris, Paul J. Overvoorde, Elizabeth Shoop, Susan Parrish, Kelynne Reed, E. Gloria Regisford, Dennis Revie, Anne G. Rosenwald, Ken Saville, Stephanie Schroeder, Mary Shaw, Gary Skuse, Christopher Smith, Mary Smith, Eric P. Spana, Mary Spratt, Joyce Stamm, Jeff S. Thompson, Matthew Wawersik, Barbara A. Wilson, Jim Youngblom, Wilson Leung, Jeremy Buhler, Elaine R. Mardis, David Lopatto, Sarah C.R. Elgin

Department of Biochemistry: Faculty Publications

Genomics is not only essential for students to understand biology but also provides unprecedented opportunities for undergraduate research. The goal of the Genomics Education Partnership (GEP), a collaboration between a growing number of colleges and universities around the country and the Department of Biology and Genome Center of Washington University in St. Louis, is to provide such research opportunities. Using a versatile curriculum that has been adapted to many different class settings, GEP undergraduates undertake projects to bring draft-quality genomic sequence up to high quality and/or participate in the annotation of these sequences. GEP undergraduates have improved more than 2 …

Mzm1 Influences A Labile Pool Of Mitochondrial Zinc Important For Respiratory Function, Aaron Atkinson, Oleh Khalimonchuk, Pamela Smith, Hana Sabic, David Eide, Dennis R. Winge

Department of Biochemistry: Faculty Publications

Zinc is essential for function of mitochondria as a cofactor for

several matrix zinc metalloproteins. We demonstrate that a

labile cationic zinc component of low molecular mass exists in

the yeast mitochondrial matrix. This zinc pool is homeostatically

regulated in response to the cellular zinc status. This pool

of zinc is functionally important because matrix targeting of a

cytosolic zinc-binding protein reduces the level of labile zinc

and interferes with mitochondrial respiratory function. We

identified a series of proteins that modulate the matrix zinc

pool, one of which is a novel conserved mitochondrial protein

designated Mzm1. Mutant mzm1∆ cells …

Identification And Characterization Of Small Compound Inhibitors Of Human Fatp2, Angel Sandoval, Aalap Chokshi, Elliot D. Jesch, Paul N. Black, Concetta C. Dirusso

Department of Biochemistry: Faculty Publications

Fatty acid transport proteins (FATPs) are bifunctional proteins, which transport long chain fatty acids into cells and activate very long chain fatty acids by esterification with coenzyme A. In an effort to understand the linkage between cellular fatty acid transport and the pathology associated with excessive accumulation of exogenous fatty acids, we targeted FATP-mediated fatty acid transport in a high throughput screen of more than 100,000 small diverse chemical compounds in yeast expressing human FATP2 (hsFATP2). Compounds were selected for their ability to depress the transport of the fluorescent long chain fatty acid analogue, C₁-BODIPY-C₁₂. Among …

Evolution Of New Enzymatic Function By Structural Modulation Of Cysteine Reactivity In Pseudomonas Fluorescens Isocyanide Hydratase, Mahadevan Lakshminarasimhan, Peter Madzelan, Ruth Nan, Nicole Marie Milkovic, Mark A. Wilson

Department of Biochemistry: Faculty Publications

Isocyanide (formerly isonitrile) hydratase (EC 4.2.1.103) is an enzyme of the DJ-1 superfamily that hydrates isocyanides to yield the corresponding N-formamide. In order to understand the structural basis for isocyanide hydratase (ICH) catalysis, we determined the crystal structures of wild-type and several site-directed mutants of Pseudomonas fluorescens ICH at resolutions ranging from 1.0 to 1.9 Å. We also developed a simple UV-visible spectrophotometric assay for ICH activity using 2-naphthyl isocyanide as a substrate. ICH contains a highly conserved cysteine residue (Cys101) that is required for catalysis and interacts with Asp17, Thr102, and an ordered water molecule in the active …

Identification And Characterization Of Oxalate Oxidoreductase, A Novel Thiamine Pyrophosphate-Dependent 2-Oxoacid Oxidoreductase That Enables Anaerobic Growth On Oxalate, Elizabeth Pierce, Donald F. Becker, Stephen W. Ragsdale

Department of Biochemistry: Faculty Publications

Moorella thermoacetica is an anaerobic acetogen, a class of bacteria that is found in the soil, the animal gastrointestinal tract, and the rumen. This organism engages the Wood-Ljungdahl pathway of anaerobic CO₂ fixation for heterotrophic or autotrophic growth. This paper describes a novel enzyme, oxalate oxidoreductase (OOR), that enables M. thermoacetica to grow on oxalate, which is produced in soil and is a common component of kidney stones. Exposure to oxalate leads to the induction of three proteins that are subunits of OOR, which oxidizes oxalate coupled to the production of two electrons and CO₂ or bicarbonate. Like …

Functional Hybrid Rubisco Enzymes With Plant Small Subunits And Algal Large Subunits Engineered Rbcs Cdna For Expression In Chlamydomonas, Todor Genkov, Moritz Meyer, Howard Griffiths, Robert J. Spreitzer

Department of Biochemistry: Faculty Publications

There has been much interest in the chloroplast-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) as a target for engineering an increase in net CO₂ fixation in photosynthesis. Improvements in the enzyme would lead to an increase in the production of food, fiber, and renewable energy. Although the large subunit contains the active site, a family of rbcS nuclear genes encodes the Rubisco small subunits, which can also influence the carboxylation catalytic efficiency and CO₂/O₂ specificity of the enzyme. To further define the role of the small subunit in Rubisco function, small subunits from spinach, Arabidopsis, …

Diversity Of Protein And Mrna Forms Of Mammalian Methionine Sulfoxide Reductase B1 Due To Intronization And Protein Processing, Xinwen Liang, Dmitri E. Fomenko, Deame Hua, Alaattin Kaya, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Background: Methionine sulfoxide reductases (Msrs) are repair enzymes that protect proteins from oxidative stress by catalyzing stereospecific reduction of oxidized methionine residues. MsrB1 is a selenocysteine-containing cytosolic/nuclear Msr with high expression in liver and kidney.

Principal Findings: Here, we identified differences in MsrB1 gene structure among mammals. Human MsrB1 gene consists of four, whereas the corresponding mouse gene of five exons, due to occurrence of an additional intron that flanks the stop signal and covers a large part of the 39-UTR. This intron evolved in a subset of rodents through intronization of exonic sequences, whereas the human gene structure represents …

Incorporating Genomics And Bioinformatics Across The Life Sciences Curriculum, Jayna L. Ditty, Christopher A. Kvaal, Brad Goodner, Sharyn K. Freyermuth, Cheryl Bailey, Robert A. Britton, Stuart G. Gordon, Sabine Heinhorst, Kelynne Reed, Zhaohui Xu, Erin R. Sanders-Lorenz, Seth Axen, Edwin Kim, Mitrick Johns, Kathleen Scott, Cheryl A. Kerfeld

Department of Biochemistry: Faculty Publications

Undergraduate life sciences education needs an overhaul, as clearly described in the National Research Council of the National Academies’ publication BIO 2010: Transforming Undergraduate Education for Future Research Biologists. Among BIO 2010’s top recommendations is the need to involve students in working with real data and tools that reflect the nature of life sciences research in the 21st century [1]. Education research studies support the importance of utilizing primary literature, designing and implementing experiments, and analyzing results in the context of a bona fide scientific question [1–12] in cultivating the analytical skills necessary to become a scientist. Incorporating these …

Regulation Of Sealing Ring Formation By L-Plastin And Cortactin In Osteoclasts, Tao Ma, Kavitha Sadashivalah, Nandakumar Madayiputhiya, Meenakshi A. Chellaia

Department of Biochemistry: Faculty Publications

The aim of this study is to identify the exact mechanism(s) by which cytoskeletal structures are modulated during bone resorption. In this study, we have shown the possible role of different actin-binding and signaling proteins in the regulation of sealing ring formation. Our analyses have demonstrated a significant increase in cortactin and a corresponding decrease in L-plastin protein levels in osteoclasts subjected to bone resorption for 18 h in the presence of RANKL, M-CSF, and native bone particles. Time-dependent changes in the localization of L-plastin (in actin aggregates) and cortactin (in the sealing ring) suggest that these proteins may be …