Altering Oligomerization Of Epha2 Via Mutations In The Intracellular Domain, 2018 The University of Akron
Altering Oligomerization Of Epha2 Via Mutations In The Intracellular Domain, Ryan W. Lingerak
Honors Research Projects
Eph receptor tyrosine kinases (RTKs) are activated by membrane-bound ligands called ephrins. Eph RTKs are divided into two subclasses, each activated by a specific classes of the ligand ephrin. The overexpression of Eph receptors is correlated to cancer cell metastasis in several different types of cancers. Studies with the EphA2 extracellular domain (ECD) and ephrinA1 ligand have shown that upon binding of ephrin to the receptor, EphA2 undergoes increased oligomerization and activation. This indicates that oligomerization is intimately connected to kinase activity. High resolution crystal structures of the EphA2 ECD have revealed some details of these ligand bound oligomers, as ...
Tea Induction Of Cyp6a8 Promoter In Drosophila Melanogaster, 2017 University of Tennessee, Knoxville
Tea Induction Of Cyp6a8 Promoter In Drosophila Melanogaster, Fiona Retzer
University of Tennessee Honors Thesis Projects
No abstract provided.
Validation Of A Hairy Roots System To Study Soybean-Soybean Aphid Interactions, 2017 Iowa State University
Validation Of A Hairy Roots System To Study Soybean-Soybean Aphid Interactions, Stephanie C. Morriss, Matthew E. Studham, Gregory L. Tylka, Gustavo C. Macintosh
The soybean aphid (Aphis glycines) is one of the main insect pests of soybean (Glycine max) worldwide. Genomics approaches have provided important data on transcriptome changes, both in the insect and in the plant, in response to the plant-aphid interaction. However, the difficulties to transform soybean and to rear soybean aphid on artificial media have hindered our ability to systematically test the function of genes identified by those analyses as mediators of plant resistance to the insect. An efficient approach to produce transgenic soybean material is the production of transformed hairy roots using Agrobacterium rhizogenes; however, soybean aphids colonize leaves ...
Knowledge-Based Versus Experimentally Acquired Distance And Angle Constraints For Nmr Structure Refinement, 2017 National Institutes of Health
Knowledge-Based Versus Experimentally Acquired Distance And Angle Constraints For Nmr Structure Refinement, Feng Cui, Robert Jernigan, Zhijun Wu
Nuclear Overhauser effects (NOE) distance constraints and torsion angle constraints are major conformational constraints for nuclear magnetic resonance (NMR) structure refinement. In particular, the number of NOE constraints has been considered as an important determinant for the quality of NMR structures. Of course, the availability of torsion angle constraints is also critical for the formation of correct local conformations. In our recent work, we have shown how a set of knowledge-based short-range distance constraints can also be utilized for NMR structure refinement, as a complementary set of conformational constraints to the NOE and torsion angle constraints. In this paper, we ...
Protein Loop Dynamics Are Complex And Depend On The Motions Of The Whole Protein, 2017 Iowa State University
Protein Loop Dynamics Are Complex And Depend On The Motions Of The Whole Protein, Michael T. Zimmermann, Robert L. Jernigan
We investigate the relationship between the motions of the same peptide loop segment incorporated within a protein structure and motions of free or end-constrained peptides. As a reference point we also compare against alanine chains having the same length as the loop. Both the analysis of atomic molecular dynamics trajectories and structure-based elastic network models, reveal no general dependence on loop length or on the number of solvent exposed residues. Rather, the whole structure affects the motions in complex ways that depend strongly and specifically on the tertiary structure of the whole protein. Both the Elastic Network Models and Molecular ...
Factors Correlating With Significant Differences Between X-Ray Structures Of Myoglobin, 2017 BioChemComp Inc
Factors Correlating With Significant Differences Between X-Ray Structures Of Myoglobin, Alexander A. Rashin, Marcin J. Domagalski, Michael T. Zimmermann, Wladek Minor, Maksymilian Chruszcz, Robert L. Jernigan
Validation of general ideas about the origins of conformational differences in proteins is critical in order to arrive at meaningful functional insights. Here, principal component analysis (PCA) and distance difference matrices are used to validate some such ideas about the conformational differences between 291 myoglobin structures from sperm whale, horse and pig. Almost all of the horse and pig structures form compact PCA clusters with only minor coordinate differences and outliers that are easily explained. The 222 whale structures form a few dense clusters with multiple outliers. A few whale outliers with a prominent distortion of the GH loop are ...
Protein Flexibility: Coordinate Uncertainties And Interpretation Of Structural Differences, Alexander A. Rashin, Abraham H. L. Rashin, Robert L. Jernigan
Valid interpretations of conformational movements in protein structures determined by X-ray crystallography require that the movement magnitudes exceed their uncertainty threshold. Here, it is shown that such thresholds can be obtained from the distance difference matrices (DDMs) of 1014 pairs of independently determined structures of bovine ribonuclease A and sperm whale myoglobin, with no explanations provided for reportedly minor coordinate differences. The smallest magnitudes of reportedly functional motions are just above these thresholds. Uncertainty thresholds can provide objective criteria that distinguish between true conformational changes and apparent `noise', showing that some previous interpretations of protein coordinate changes attributed to external ...
Reverse-Genetic Analysis Of The Two Biotin-Containing Subunit Genes Of The Heteromeric Acetyl-Coenzyme A Carboxylase In Arabidopsis Indicates A Unidirectional Functional Redundancy, 2017 Iowa State University
Reverse-Genetic Analysis Of The Two Biotin-Containing Subunit Genes Of The Heteromeric Acetyl-Coenzyme A Carboxylase In Arabidopsis Indicates A Unidirectional Functional Redundancy, Xu Li, Hilal Ilarslan, Libuse Brachova, Hui-Rong Qian, Ling Li, Ping Che, Eve Syrkin Wurtele, Basil J. Nikolau
The heteromeric acetyl-coenzyme A carboxylase catalyzes the first and committed reaction of de novo fatty acid biosynthesis in plastids. This enzyme is composed of four subunits: biotin carboxyl-carrier protein (BCCP), biotin carboxylase, α-carboxyltransferase, and β-carboxyltransferase. With the exception of BCCP, single-copy genes encode these subunits in Arabidopsis (Arabidopsis thaliana). Reverse-genetic approaches were used to individually investigate the physiological significance of the two paralogous BCCP-coding genes, CAC1A (At5g16390, codes for BCCP1) and CAC1B (At5g15530, codes for BCCP2). Transfer DNA insertional alleles that completely eliminate the accumulation of BCCP2 have no perceptible effect on plant growth, development, and fatty acid accumulation. In ...
Genome Wide Co-Expression Among The Starch Debranching Enzyme Genes Atisa1, Atisa2, And Atisa3 In Arabidopsis Thaliana, Ling Li, Hilal Ilarslan, Martha G. James, Alan M. Myers, Eve Syrkin Wurtele
Each of four starch debranching enzymes (DBE) is distinct and highly conserved across the plant kingdom; however, the specific functions of these proteins in carbohydrate metabolism are not well understood. DBEs function in both biosynthesis and degradation of starch, and two have been shown to function as multimers in various quarternary structures that can contain one or more DBE proteins, i.e. ISA1 homomultimers and ISA1/ISA2 heteromultimers. This study characterizes potential functional relationships between the three isoamylase-type DBE proteins (ISA) of Arabidopsis using a comprehensive bioinformatics analysis and promoter fusion approach to determine tissue-, subcellular-, and temporal specificity of ...
Jennifer Maurer Phd Thesis.Pdf, 2017 University of Massachusetts Medical School
Jennifer Maurer Phd Thesis.Pdf, Jennifer Maurer
Biased Genetic Screen Identifies Novel Genes Involved In Antiviral Defense, 2017 Louisiana State University and Agricultural and Mechanical College
Biased Genetic Screen Identifies Novel Genes Involved In Antiviral Defense, Tianyun Long
LSU Doctoral Dissertations
RNA interference (RNAi) mediates potent antiviral response across kingdoms. In Caenorhabditis elegans nematodes, antiviral RNAi requires a virus sensor that is conserved in mammals and is amplified by secondary small interfering RNAs that are produced in a Dicer-independent manner.
To better understand worm antiviral RNAi, I carried out a biased genetic screen, aiming to identify novel antiviral RNAi genes. To speed up the gene discovery process, the reporter worms used for this genetic screen were engineered to contain extra copies of 4 known antiviral RNAi genes. Therefore, genetic alleles derived from these 4 genes will be automatically rejected during ...
Investigating The Toxicity And Accumulation Of 2,4-Dichlorophenoxyacetic Acid (2,4-D) And Glyphosate In Eisenia Fetida, Caitlin Lazurick, Nicole Lidzbarski, Rachel Owings, Jeff Brotherton, Edna Steele
Journal of the South Carolina Academy of Science
Glyphosate, the main ingredient in Roundup®, is the most widely used herbicide in the world. It is also used in combination with another effective herbicide, 2,4-D, in the formulation called Enlist Duo®. The EPA approved the use of Enlist Duo® on certain crops including those genetically modified to be resistant to both herbicides. The predicted significant increase in the use of these herbicides raised concerns from the general public because both compounds have been classified as possibly or probably carcinogenic. Since herbicides are applied directly to vegetation, the safety of organisms that come in contact with the herbicides is ...
An Organismal Model For Gene Regulatory Networks In The Gut-Associated Immune Response, 2017 George Washington University
An Organismal Model For Gene Regulatory Networks In The Gut-Associated Immune Response, Katherine M. Buckley, J P. Rast
Biochemistry and Molecular Medicine Faculty Publications
The gut epithelium is an ancient site of complex communication between the animal immune system and the microbial world. While elements of self-non-self receptors and effector mechanisms differ greatly among animal phyla, some aspects of recognition, regulation, and response are broadly conserved. A gene regulatory network (GRN) approach provides a means to investigate the nature of this conservation and divergence even as more peripheral functional details remain incompletely understood. The sea urchin embryo is an unparalleled experimental model for detangling the GRNs that govern embryonic development. By applying this theoretical framework to the free swimming, feeding larval stage of the ...
Functional Analysis Of Drosophila Integrator Complex In Snrna 3' End Processing, 2017 The University of Texas Graduate School of Biomedical Sciences at Houston
Functional Analysis Of Drosophila Integrator Complex In Snrna 3' End Processing, Jiandong Chen
Uridine-rich small nuclear RNAs (U snRNAs) play essential roles in eukaryotic gene expression by facilitating the removal of introns from mRNA precursors and the processing of the replication-dependent histone pre-mRNAs. Formation of the 3’ end of these snRNAs is carried out by a poorly characterized, twelve-membered protein complex named Integrator Complex.
In the effort to understand Integrator Complex function in the formation of the snRNA 3’ end, we performed a functional RNAi screen in Drosophila S2 cells to identify protein factors required for snRNA 3’ end formation. This screen was conducted by using a fluorescence-based reporter that elicits GFP expression ...
Prebiotic Rna Network Formation: A Taxonomy Of Molecular Cooperation, 2017 Arizona State University
Prebiotic Rna Network Formation: A Taxonomy Of Molecular Cooperation, Cole Mathis, Sanjay N. Ramprasad, Sara Imari Walker, Niles Lehman
Chemistry Faculty Publications and Presentations
Cooperation is essential for evolution of biological complexity. Recent work has shown game theoretic arguments, commonly used to model biological cooperation, can also illuminate the dynamics of chemical systems. Here we investigate the types of cooperation possible in a real RNA system based on the Azoarcusribozyme, by constructing a taxonomy of possible cooperative groups. We construct a computational model of this system to investigate the features of the real system promoting cooperation. We find triplet interactions among genotypes are intrinsically biased towards cooperation due to the particular distribution of catalytic rate constants measured empirically in the real system. For other ...
Purification From Human Milk Of Matriptase Complexes With Secreted Serpins: Mechanism For Inhibition Of Matriptase Other Than Hai-1, 2017 University of Maryland at Baltimore
Purification From Human Milk Of Matriptase Complexes With Secreted Serpins: Mechanism For Inhibition Of Matriptase Other Than Hai-1, I-Chu Tseng, Feng-Pai Chou, Sheng-Feng Su, Michael Oberst, Nandakumar Madayiputhiya, Ming-Shyue Lee, Jehng-Kang Wang, David E. Sloane, Michael Johnson, Chen-Yong Lin
Michael C. Johnson
Matriptase, a type 2 transmembrane serine protease, is predominately expressed by epithelial and carcinoma cells in which hepatocyte growth factor activator inhibitor 1 (HAI-1), a membrane-bound, Kunitz-type serine protease inhibitor, is also expressed. HAI-1 plays dual roles in the regulation of matriptase, as a conventional protease inhibitor and as a factor required for zymogen activation of matriptase. As a consequence, activation of matriptase is immediately followed by HAI-1-mediated inhibition, with the activated matriptase being sequestered into HAI-1 complexes. Matriptase is also expressed by peripheral blood leukocytes, such as monocytes and macrophages; however, in contrast to epithelial cells, monocytes and macrophages ...
The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, 2017 Radford University
The Behavior Response Of Antlion Larvae To Alternating Magnetic Fields, Lindsey Wagner, Caleb L. Adams
Annual Symposium on Biomathematics and Ecology: Education and Research
No abstract provided.
Functional Characteristics And Genomic Sequencing Of Antarctic Environmental Isolates, 2017 Minnesota State University Moorhead
Functional Characteristics And Genomic Sequencing Of Antarctic Environmental Isolates, Amanda Kemper, Christina Aigner, Michelle Tigges, Sara Anderson
Annual Symposium on Biomathematics and Ecology: Education and Research
No abstract provided.
Human Rickettsial Pathogen Modulates Arthropod Organic Anion Transporting Polypeptide And Tryptophan Pathway For Its Survival In Ticks, Vikas Taank, Shovan Dutta, Amrita Dasgupta, Durland Fish, John F. Anderson, Hameeda Sultana, Girish Neelakanta
Biological Sciences Faculty Publications
The black-legged tick Ixodes scapularis transmits the human anaplasmosis agent, Anaplasma phagocytophilum. In this study, we show that A. phagocytophilum specifically up-regulates I. scapularis organic anion transporting polypeptide, isoatp4056 and kynurenine amino transferase (kat), a gene involved in the production of tryptophan metabolite xanthurenic acid (XA), for its survival in ticks. RNAi analysis revealed that knockdown of isoatp4056 expression had no effect on A. phagocytophilum acquisition from the murine host but affected the bacterial survival in tick cells. Knockdown of the expression of kat mRNA alone or in combination with isoatp4056 mRNA significantly affected A. phagocytophilum survival and isoatp4056 expression ...
Ydj1 Governs Fungal Morphogenesis And Stress Response, And Facilitates Mitochondrial Protein Import Via Mas1 And Mas2, Jinglin L. Xie, Iryna Bohovych, Erin O.Y. Wong, Jean-Philippe Lambert, Anne-Claude Gingras, Oleh Khalimonchuk, Leah E. Cowen, Michelle D. Leach
Biochemistry -- Faculty Publications
Mitochondria underpin metabolism, bioenergetics, signalling, development and cell death in eukaryotes. Most of the ~1,000 yeast mitochondrial proteins are encoded in the nucleus and synthesised as precursors in the cytosol, with mitochondrial import facilitated by molecular chaperones. Here, we focus on the Hsp40 chaperone Ydj1 in the fungal pathogen Candida albicans, finding that it is localised to both the cytosol and outer mitochondrial membrane, and is required for cellular stress responses and for filamentation, a key virulence trait. Mapping the Ydj1 protein interaction network highlighted connections with co-chaperones and regulators of filamentation. Furthermore, the mitochondrial processing peptidases Mas1 and ...