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Articles 1 - 15 of 15

Full-Text Articles in Molecular Biology

(R)-Β-Lysine Modified Elongation Factor P Functions In Translation Elongation, Tammy J. Bullwinkle, S. Betty Zou, Andrei Rajkovic, Steven J. Hersch, Sara Elgamal, Nathaniel Robinson, David Smil, Yuri Bolshan, William Wiley Navarre, Michael Ibba Dec 2012

(R)-Β-Lysine Modified Elongation Factor P Functions In Translation Elongation, Tammy J. Bullwinkle, S. Betty Zou, Andrei Rajkovic, Steven J. Hersch, Sara Elgamal, Nathaniel Robinson, David Smil, Yuri Bolshan, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Post-translational modification of bacterial elongation factor P (EF-P) with (R)-β-lysine at a conserved lysine residue activates the protein in vivo and increases puromycin reactivity of the ribosome in vitro. The additional hydroxylation of EF-P at the same lysine residue by the YfcM protein has also recently been described. The roles of modified and unmodified EF-P during different steps in translation, and how this correlates to its physiological role in the cell, have recently been linked to the synthesis of polyproline stretches in proteins. Polysome analysis indicated that EF-P functions in translation elongation, rather than initiation as proposed previously. This was …


Selection Of Trna Charging Quality Control Mechanisms That Increase Mistranslation Of The Genetic Code, Srujana S. Yadavalli, Michael Ibba Dec 2012

Selection Of Trna Charging Quality Control Mechanisms That Increase Mistranslation Of The Genetic Code, Srujana S. Yadavalli, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mistranslation can follow two events during protein synthesis: production of non-cognate amino acid:transfer RNA (tRNA) pairs by aminoacyl-tRNA synthetases (aaRSs) and inaccurate selection of aminoacyl-tRNAs by the ribosome. Many aaRSs actively edit non-cognate amino acids, but editing mechanisms are not evolutionarily conserved, and their physiological significance remains unclear. To address the connection between aaRSs and mistranslation, the evolutionary divergence of tyrosine editing by phenylalanyl-tRNA synthetase (PheRS) was used as a model. Certain PheRSs are naturally error prone, most notably a Mycoplasma example that displayed a low level of specificity consistent with elevated mistranslation of the proteome. Mycoplasma PheRS was found …


Structure-Function Analysis Of A Protein Encoded By The Bhv-1 Latency Related Gene, Devis Sinani Dec 2012

Structure-Function Analysis Of A Protein Encoded By The Bhv-1 Latency Related Gene, Devis Sinani

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine herpes virus 1 (BHV-1) is a significant viral pathogen in cattle that induces a myriad of clinical symptoms. These symptoms include: conjunctivitis, upper respiratory tract infections, genital disorders, and abortions. BHV-1 infection can also lead to transient immune-suppression, which predisposes cattle to secondary bacterial infection leading to life-threatening pneumonia referred to as bovine respiratory disease (BRD). Following acute infection, BHV-1 establishes latency in sensory neurons within trigeminal ganglia. Reactivation of the virus can occur periodically, resulting in virus transmission. The latency-related (LR) RNA is the only abundantly expressed transcript in latently infected sensory neurons and it encodes several proteins, …


Taking Aim At The Start Of Translation, Medha Raina, Michael Ibba Aug 2012

Taking Aim At The Start Of Translation, Medha Raina, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

No abstract provided.


Discrimination Of Colon Cancer Stem Cells Using Noncanonical Amino Acid, Xinrui Duan, Honglin Li, Hexin Chen, Qian Wang Jul 2012

Discrimination Of Colon Cancer Stem Cells Using Noncanonical Amino Acid, Xinrui Duan, Honglin Li, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells (CSCs) may be responsible for tumor recurrence. Metabolic labelling of newly synthesized proteins with non-canonical amino acids allows us to discriminate CSCs in mixed populations due to the quiescent nature of these cells.


A Pseudo-Trna Modulates Antibiotic Resistance In Bacillus Cereus, Theresa E. Rogers, Sandro F. Ataide, Kiley Dare, Assaf Katz, Stephanie Seveau, Hervé Roy, Michael Ibba Jul 2012

A Pseudo-Trna Modulates Antibiotic Resistance In Bacillus Cereus, Theresa E. Rogers, Sandro F. Ataide, Kiley Dare, Assaf Katz, Stephanie Seveau, Hervé Roy, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial genomic islands are often flanked by tRNA genes, which act as sites for the integration of foreign DNA into the host chromosome. For example, Bacillus cereus ATCC14579 contains a pathogenicity island flanked by a predicted pseudo-tRNA, tRNAOther, which does not function in translation. Deletion of tRNAOther led to significant changes in cell wall morphology and antibiotic resistance and was accompanied by changes in the expression of numerous genes involved in oxidative stress responses, several of which contain significant complementarities to sequences surrounding tRNAOther. This suggested that tRNAOther might be expressed as part of a larger RNA, and RACE analysis …


Association Of A Multi-Synthetase Complex With Translating Ribosomes In The Archaeon Thermococcus Kodakarensis, Medha Raina, Sara Elgamal, Thomas J. Santangelo, Michael Ibba Jun 2012

Association Of A Multi-Synthetase Complex With Translating Ribosomes In The Archaeon Thermococcus Kodakarensis, Medha Raina, Sara Elgamal, Thomas J. Santangelo, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In archaea and eukaryotes aminoacyl-tRNA synthetases (aaRSs) associate in multi-synthetase complexes (MSCs), however the role of such MSCs in translation is unknown. MSC function was investigated in vivo in the archaeon Thermococcus kodakarensis, wherein six aaRSs were affinity co-purified together with several other factors involved in protein synthesis, suggesting that MSCs may interact directly with translating ribosomes. In support of this hypothesis, the aminoacyltRNA synthetase (aaRS) activities of the MSC were enriched in isolated T. kodakarensis polysome fractions. These data indicate that components of the archaeal protein synthesis machinery associate into macromolecular assemblies in vivo and provide the potential …


Heterotopic Ossification: Cellular Basis, Symptoms, And Treatment, Brian Wolfe Apr 2012

Heterotopic Ossification: Cellular Basis, Symptoms, And Treatment, Brian Wolfe

Senior Honors Theses

Heterotopic ossification (HO) is the process by which calcified bone develops in soft tissues. Because of the abnormal calcification, complications such as bone deformation, loss of range of motion, and joint immobility adversely affect patients. There are many genetic types of heterotopic ossification, namely fibrodysplasia ossificans progressiva, progressive osseous heteroplasia, and Albright hereditary osteodystrophy. However, this condition can also arise from surgery, burns, or traumatic injuries, so it is seen as an important area for research in the future. There are various treatments available such as non-steroidal anti-inflammatory drugs and radiation therapy, as well as combinations of the two. The …


Analysis Of The Effects And Current Treatments Of Laminin Deficiency, Joshua Mark Reynolds Apr 2012

Analysis Of The Effects And Current Treatments Of Laminin Deficiency, Joshua Mark Reynolds

Senior Honors Theses

Laminin (LM) is a network of proteins that functions as a connective framework of most cells in the body. It is composed of multiple different subunits and therefore has many different variations. It is a trimeric protein, meaning that it is composed primarily of ⍺, β, and γ chains. The differentiation of these subunits is what gives the different variants their functions. In addition, although LM is the primary molecule in scope, the network of other connective proteins involved in LM-associated diseases will also be covered in lesser detail because molecules like dystrophin, dystroglycan, collagen, and integrin are vital to …


Cryo-Em Structure Of The Archaeal 50s Ribosomal Subunit In Complex With Initiation Factor 6 And Implications For Ribosome Evolution, Basil J. Greber, Daniel Boehringer, Vlatka Godinic-Mikulcic, Ana Crnkovic, Michael Ibba, Ivana Weygand-Durasevic, Nenad Ban Jan 2012

Cryo-Em Structure Of The Archaeal 50s Ribosomal Subunit In Complex With Initiation Factor 6 And Implications For Ribosome Evolution, Basil J. Greber, Daniel Boehringer, Vlatka Godinic-Mikulcic, Ana Crnkovic, Michael Ibba, Ivana Weygand-Durasevic, Nenad Ban

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translation of mRNA into proteins by the ribosome is universally conserved in all cellular life. The composition and complexity of the translation machinery differ markedly between the three domains of life. Organisms from the domain Archaea show an intermediate level of complexity, sharing several additional components of the translation machinery with eukaryotes that are absent in bacteria. One of these translation factors is initiation factor 6 (IF6), which associates with the large ribosomal subunit. We have reconstructed the 50S ribosomal subunit from the archaeon Methanothermobacter thermautotrophicus in complex with archaeal IF6 at 6.6 Å resolution using cryo-electron microscopy (EM). The …


Roles Of Trna In Cell Wall Biosynthesis, Kiley Dare, Michael Ibba Jan 2012

Roles Of Trna In Cell Wall Biosynthesis, Kiley Dare, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent research into various aspects of bacterial metabolism such as cell wall and antibiotic synthesis, degradation pathways, cellular stress, and amino acid biosynthesis has elucidated roles of aminoacyl‐transfer ribonucleic acid (aa‐tRNA) outside of translation. Although the two enzyme families responsible for cell wall modifications, aminoacyl‐phosphatidylglycerol synthases (aaPGSs) and Fem, were discovered some time ago, they have recently become of intense interest for their roles in the antimicrobial resistance of pathogenic microorganisms. The addition of positively charged amino acids to phosphatidylglycerol (PG) by aaPGSs neutralizes the lipid bilayer making the bacteria less susceptible to positively charged antimicrobial agents. Fem transferases utilize …


The Role Of Ezh2 In The Regulation Of The Activity Of Matrix Metalloproteinases In Prostate Cancer Cells., Yong Jae Shin, Jeong-Ho Kim Jan 2012

The Role Of Ezh2 In The Regulation Of The Activity Of Matrix Metalloproteinases In Prostate Cancer Cells., Yong Jae Shin, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

Degradation of the extracellular matrix (ECM), a critical step in cancer metastasis, is determined by the balance between MMPs (matrix metalloproteinases) and their inhibitors TIMPs (tissue inhibitors of metalloproteinases). In cancer cells, this balance is shifted towards MMPs, promoting ECM degradation. Here, we show that EZH2 plays an active role in this process by repressing the expression of TIMP2 and TIMP3 in prostate cancer cells. The TIMP genes are derepressed by knockdown of EZH2 expression in human prostate cancer cells but repressed by overexpression of EZH2 in benign human prostate epithelial cells. EZH2 catalyzes H3K27 trimethylation and subsequent DNA methylation …


Linus Pauling: Scientist Of The 20th Century, Laura Ward Jan 2012

Linus Pauling: Scientist Of The 20th Century, Laura Ward

Natural Sciences Student Research Presentations

This poster describes the contributions scientist Linus Pauling made to the fields of chemistry and molecular biology, including his hybridization theory.


Signals From Intraventricular Depth Electrodes Can Control A Brain-Computer Interface, Jerry J. Shih, Dean J. Krusienski Jan 2012

Signals From Intraventricular Depth Electrodes Can Control A Brain-Computer Interface, Jerry J. Shih, Dean J. Krusienski

Electrical & Computer Engineering Faculty Publications

A Brain-Computer Interface (BCI) is a device that enables severely disabled people to communicate and interact with their environments using their brain waves. Most research investigating BCI in humans have used scalp-recorded electroencephalography (EEG). We have recently demonstrated that signals from intracranial electrocorticography (ECoG) and stereotactic depth electrodes (SDE) in the hippocampus can be used to control a BCI P300 Speller paradigm. We report a case in which stereotactic depth electrodes positioned in the ventricle were able to obtain viable signals for a BCI. Our results demonstrate that event-related potentials from intraventricular electrodes can be used to reliably control the …


Microfluidic Impedance Spectroscopy As A Tool For Quantitative Biology And Biotechnology, Ahmet C. Sabuncu, Jie Zhuang, Juergen F. Kolb, Ali Beskok Jan 2012

Microfluidic Impedance Spectroscopy As A Tool For Quantitative Biology And Biotechnology, Ahmet C. Sabuncu, Jie Zhuang, Juergen F. Kolb, Ali Beskok

Mechanical & Aerospace Engineering Faculty Publications

A microfluidic device that is able to perform dielectric spectroscopy is developed. The device consists of a measurement chamber that is 250 μm thick and 750 μm radius. Around 1000 cells fit inside the chamber assuming average quantities for cell radius and volume fraction. This number is about 1000 folds lower than the capacity of conventional fixtures. A T-cell leukemia cell line Jurkat is tested using the microfluidic device. Measurements of deionized water and salt solutions are utilized to determine parasitic effects and geometric capacitance of the device. Physical models, including Maxwell-Wagner mixture and double shell models, are used to …