Molecular Biology Commons^™

Extracellular Matrix In Development And Disease, Julia Thom Oxford, Jonathon C. Reeck, Makenna J. Hardy

Biomolecular Research Center Publications and Presentations

The evolution of multicellular metazoan organisms was marked by the inclusion of an extracellular matrix (ECM), a multicomponent, proteinaceous network between cells that contributes to the spatial arrangement of cells and the resulting tissue organization. The development of an ECM that provides support in larger organisms may have represented an advantage in the face of selection pressure for the evolution of the ECM.

Hla-Do Modulates The Diversity Of The Mhc-Ii Self-Peptidome, Padma P. Nanaware, Mollie M. Jurewicz, John D. Leszyk, Scott A. Shaffer, Lawrence J. Stern

Open Access Articles

Presentation of antigenic peptides on MHC-II molecules is essential for tolerance to self and for initiation of immune responses against foreign antigens. DO (HLA-DO in humans, H2-O in mice) is a non-classical MHC-II protein that has been implicated in control of autoimmunity and regulation of neutralizing antibody responses to viruses. These effects likely are related to a role of DO in selecting MHC-II epitopes, but previous studies examining the effect of DO on presentation of selected CD4 T cell epitopes have been contradictory. To understand how DO modulates MHC-II antigen presentation, we characterized the full spectrum of peptides presented by ...

Membrane Protein Nanoparticles: The Shape Of Things To Come, Kailene S. Simon, Naomi L. Pollock, Sarah C. Lee

Open Access Articles

The use of styrene-maleic acid (SMA) for the purification of a wide range of membrane proteins (MPs) from both prokaryotic and eukaryotic sources has begun to make an impact in the field of MP biology. This method is growing in popularity as a means to purify and thoroughly investigate the structure and function of MPs and biological membranes. The amphiphilic SMA copolymer can effectively extract MPs directly from a native lipid bilayer to form discs approximately 10 nm in diameter. The resulting lipid particles, or styrene-maleic acid lipid particles (SMALPs), contain SMA, protein and membrane lipid. MPs purified in SMALPs ...

Resistance From Afar: Distal Mutation V36m Allosterically Modulates The Active Site To Accentuate Drug Resistance In Hcv Ns3/4a Protease, Aysegul Ozen, Kuan-Hung Lin, Keith P. Romano, Davide Tavella, Alicia Newton, Christos J. Petropoulos, Wei Huang, Cihan Aydin, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Hepatitis C virus rapidly evolves, conferring resistance to direct acting antivirals. While resistance via active site mutations in the viral NS3/4A protease has been well characterized, the mechanism for resistance of non-active site mutations is unclear. R155K and V36M often co-evolve and while R155K alters the electrostatic network at the binding site, V36M is more than 13 Angstrom away. In this study the mechanism by which V36M confers resistance, in the context of R155K, is elucidated with drug susceptibility assays, crystal structures, and molecular dynamics (MD) simulations for three protease inhibitors: telaprevir, boceprevir and danoprevir. The R155K and R155K ...

Orbit: A New Paradigm For Genetic Engineering Of Mycobacterial Chromosomes, Kenan C. Murphy, Samantha J. Nelson, Subhalaxmi Nambi, Kadamba Papavinasasundaram, Christina E. Baer, Christopher M. Sassetti

Open Access Articles

Two efficient recombination systems were combined to produce a versatile method for chromosomal engineering that obviates the need to prepare double-stranded DNA (dsDNA) recombination substrates. A synthetic "targeting oligonucleotide" is incorporated into the chromosome via homologous recombination mediated by the phage Che9c RecT annealase. This oligonucleotide contains a site-specific recombination site for the directional Bxb1 integrase (Int), which allows the simultaneous integration of a "payload plasmid" that contains a cognate recombination site and a selectable marker. The targeting oligonucleotide and payload plasmid are cotransformed into a RecT- and Int-expressing strain, and drug-resistant homologous recombinants are selected in a single step ...

The Effects Of Inulin And Galactooligosaccharides On The Production Of Reuterin By Lactobacillus Reuteri, Micah Dwight Forshee

ELAIA

The microbiome is a dynamic community that can positively and negatively influence host health. Lactobacillus reuteri is a probiotic that has received much attention for its ability to inhibit pathogens such as Salmonella typhimurium, Escherichia coli, and Clostridium difficile. It does so by its unique ability to metabolize glycerol into the antimicrobial compound 3-HPA, which is commonly referred to as reuterin. The ability to secrete reuterin is dependent not only on glycerol availability but also the concentration of glucose. In fact, there appears to be a “goldilocks” ratio between glucose and glycerol as either too much or too little glucose ...

General Decapping Activators Target Different Subsets Of Inefficiently Translated Mrnas, Feng He, Alper Celik, Chan Wu, Allan Jacobson

Open Access Articles

The Dcp1-Dcp2 decapping enzyme and the decapping activators Pat1, Dhh1, and Lsm1 regulate mRNA decapping, but their mechanistic integration is unknown. We analyzed the gene expression consequences of deleting PAT1, LSM1, or DHH1, or the DCP2 C-terminal domain, and found that: i) the Dcp2 C-terminal domain is an effector of both negative and positive regulation; ii) rather than being global activators of decapping, Pat1, Lsm1, and Dhh1 directly target specific subsets of yeast mRNAs and loss of the functions of each of these factors has substantial indirect consequences for genome-wide mRNA expression; and iii) transcripts targeted by Pat1, Lsm1, and ...

Potent Cas9 Inhibition In Bacterial And Human Cells By Acriic4 And Acriic5 Anti-Crispr Proteins, Jooyoung Lee, Aamir Mir, Alireza Edraki, Bianca Garcia, Nadia Amrani, Hannah E. Lou, Ildar Gainetdinov, April Pawluk, Raed Ibraheim, Xin D. Gao, Pengpeng Liu, Alan R. Davidson, Karen L. Maxwell, Erik J. Sontheimer

Open Access Articles

In their natural settings, CRISPR-Cas systems play crucial roles in bacterial and archaeal adaptive immunity to protect against phages and other mobile genetic elements, and they are also widely used as genome engineering technologies. Previously we discovered bacteriophage-encoded Cas9-specific anti-CRISPR (Acr) proteins that serve as countermeasures against host bacterial immunity by inactivating their CRISPR-Cas systems (A. Pawluk, N. Amrani, Y. Zhang, B. Garcia, et al., Cell 167:1829-1838.e9, 2016, https://doi.org/10.1016/j.cell.2016.11.017). We hypothesized that the evolutionary advantages conferred by anti-CRISPRs would drive the widespread occurrence of these proteins in nature (K ...

Virulence Regulation In Pseudomonas Aeruginosa Via The Alginate Regulators, Algu And Algr, The Posttranscriptional Regulator, Rsma, And The Two-Component System, Algz/R, Sean Stacey

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a Gram-negative bacillus able to colonize a wide variety of environments. In the human host, P. aeruginosa can establish an acute infection or persist and create a chronic infection. P. aeruginosa is able to establish a niche and persist in human hosts by using a wide array of virulence factors used for: movement, killing host cells, and evading immune cells and antibiotics. Understanding virulence factors and their regulation has proved to be an important means of combating the morbidity and mortality of P. aeruginosa as well as the ever-increasing threat of drug resistance. By targeting virulence factors ...

Role Of P300 Zz Domain In Chromatin Association And Histone Acetylation, Yongming Xue

UT GSBS Dissertations and Theses (Open Access)

Transcription is strictly regulated by numerous factors including transcription coactivators. The p300 protein and its close paralogue CREB-binding protein (CREBBP, aka CBP) are well-known transcriptional coactivators that have intrinsic lysine acetyltransferase activity. The functions of p300/CBP largely rely on their capabilities to bind to chromatin and to acetylate the histone substrates. However, the molecular mechanisms underlying the regulation of these processes are not fully understood.

Through combination of various biochemical, biophysical and molecular approaches, we show that the ZZ-type zinc finger (ZZ) domain of p300 functions as a histone reader that specifically binds the N-terminal tail of histone H3 ...

Investigating Autophagy Dysfunction Induced By A Parkinson's Disease-Causing Mutation In Vps35, Abir Ashfakur Rahman

Boise State University Theses and Dissertations

Parkinson’s Disease (PD) is an idiopathic disorder with no known cure. With number of cases steadily rising around the world, it is imperative to turn to the underlying cellular and molecular mechanisms of the disease manifestation and neurodegeneration to craft novel modes of therapy. VPS35 is one of the few genes that have identified and definitively linked to familial PD. The particular mutation that has been associated is known to cause dysfunction of a key cellular process known as autophagy. This process is primarily responsible for clearance of unwanted, damaged or misfolded proteins, among other things. Our study reveals ...

Ph-Induced Folding Of The Caspase-Cleaved Par-4 Tumor Suppressor: Evidence Of Structure Outside Of The Coiled Coil Domain, Andrea M. Clark, Komala Ponniah, Meghan S. Warden, Emily M. Raitt, Andrea C. Yawn, Stephen M. Pascal

Chemistry & Biochemistry Faculty Publications

Prostate apoptosis response-4 (Par-4) is a 38 kDa largely intrinsically disordered tumor suppressor protein that functions in cancer cell apoptosis. Par-4 down-regulation is often observed in cancer while up-regulation is characteristic of neurodegenerative conditions such as Alzheimer’s disease. Cleavage of Par-4 by caspase-3 activates tumor suppression via formation of an approximately 25 kDa fragment (cl-Par-4) that enters the nucleus and inhibits Bcl-2 and NF-ƙB, which function in pro-survival pathways. Here, we have investigated the structure of cl-Par-4 using biophysical techniques including circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), and intrinsic tyrosine fluorescence. The results demonstrate pH-dependent folding of ...

Evaluation Of Motor Cortex Neuronal Morphology In Developmental Hyperserotonemia Rat Model, Colten Z. Dillinger

MSU Graduate Theses

Fetal serotonin levels are involved in the development of the serotonergic system in an autoregulatory manner as well as the organization and connectivity of non-serotonergic neurons. Insufficient serotonin levels during development result in improper neuronal maturation and decreased synaptogenesis. Conversely, excess developmental serotonin levels can alter the progression of serotonergic neurons, ultimately resulting in a chronic decrease of serotonin in the developed brain via a negative feedback mechanism. There is a known correlation between autistic patients and chronically decreased brain serotonin concentrations; this is potentially implicated in the impaired development of the autistic brain. Incomplete or delayed development of motor ...

Genetic And Epigenetic Investigations On Pulmonary Hypertension Syndrome In Meat Type- Chickens, Khaloud Alzahrani

Theses and Dissertations

This dissertation presents a collection of studies that investigate the genetic and epigenetic associations to ascites phenotype in broiler chickens. Ascites is a significant metabolic disease associated with fast-growing meat-type chickens (broilers) and is a terminal result of pulmonary hypertension syndrome PHS. It is a multi-factorial syndrome caused by interactions between genetic, physiological, environmental, and managemental factors. It was estimated that ascites accounts for losses of about US$1 billion annually worldwide and for over 25% of broilers mortality. Although traditional and molecular genetic methods in the selection and in performance improvements, has greatly reduced ascites frequency, yet it has ...

Assessment Of Salmonella Enterica Biofilms And Expression Differences Among Serovars, Zhaohao Shi

Theses and Dissertations

Biofilms are communities of microorganisms associated by a matrix of extracellular polymers. In this state, microorganisms occupy an ecological niche distinct from their free-floating, planktonic counterparts. Also, biofilm bacteria become biologically unique as they form communities and lose motility. The acquisition of these physiological attributes enables the biofilm to persist through harsh environmental conditions, including antimicrobial induced stress and to resist sanitization efforts. Because of these features, biofilms can rapidly disseminate across numerous surfaces and as they establish, become challenging to remove. This is a particular issue for the food industry as processing plants offer favorable conditions for biofilm formation ...

A Simple Metabolic Switch May Activate Apomixis In Arabidopsis Thaliana, David Alan Sherwood

All Graduate Theses and Dissertations

Apomixis, asexual or clonal seed production in plants, can decrease the cost of producing hybrid seed and enable currently open pollinated crops to be converted to more vigorous and higher yielding hybrids that can reproduce themselves through their own seed. Sexual reproduction may be triggered by a programmed stress signaling event that occurs in both the meiocyte, just prior to meiosis, and later in the egg just prior to embryo sac maturation. The prevention of stress signaling and the activation of a pro-growth signal prior to meiosis triggered apomeiosis, the first half of apomixis. The same approach was used prior ...

Identification Of Deubiquitinating Enzymes That Control The Cell Cycle In Saccharomyces Cerevisiae, Claudine E. Mapa

GSBS Dissertations and Theses

A large fraction of the proteome displays cell cycle-dependent expression, which is important for cells to accurately grow and divide. Cyclical protein expression requires protein degradation via the ubiquitin proteasome system (UPS), and several ubiquitin ligases (E3) have established roles in this regulation. Less is understood about the roles of deubiquitinating enzymes (DUB), which antagonize E3 activity. A few DUBs have been shown to interact with and deubiquitinate cell cycle-regulatory E3s and their protein substrates, suggesting DUBs play key roles in cell cycle control. However, in vitro studies and characterization of individual DUB deletion strains in yeast suggest that these ...

Deciphering The Molecular Basis Of Mycobacteria And Lipoglycan Recognition By The C-Type Lectin Dectin-2, Alexiane Decout, Devinder Kaur, Jerome Nigou

Open Access Articles

Dectin-2 is a C-type lectin involved in the recognition of several pathogens such as Aspergillus fumigatus, Candida albicans, Schistosoma mansonii, and Mycobacterium tuberculosis that triggers Th17 immune responses. Identifying pathogen ligands and understanding the molecular basis of their recognition is one of the current challenges. Purified M. tuberculosis mannose-capped lipoarabinomannan (ManLAM) was shown to induce signaling via Dectin-2, an activity that requires the (alpha1 --> 2)-linked mannosides forming the caps. Here, using isogenic M. tuberculosis mutant strains, we demonstrate that ManLAM is a bona fide and actually the sole ligand mediating bacilli recognition by Dectin-2, although M. tuberculosis produces a ...

Development Of A Pd-L1 Pet Imaging Biomarker, Caleb Jack Bridgwater

Posters-at-the-Capitol

Immunotherapy strategies are very promising treatments for cancer patients. Specifically, Immune checkpoint inhibitor therapy focusing on the PD-1/PD-L1 pathway shows long-lasting positive results in many cancer patients. Unfortunately, not all the patients can benefit from this highly effective treatment. Hence, there is a great need for predictive biomarkers. Immunohistochemical (IHC) staining has been used as a way of predicting patient response, yet shows many problems. For example, IHC utilizes an invasive biopsy and sample fixing, which creates an incomplete and delayed picture of the patient’s biochemistry and the tumor microenvironment, consequently ignoring metastases.

The purpose of this study ...

Combined High-Speed Single Particle Tracking Of Membrane Proteins And Super-Resolution Of Membrane-Associated Structures, Hanieh Mazloom Farsibaf, Keith A. Lidke

Shared Knowledge Conference

Many experiments have shown that the diffusive motion of lipids and membrane proteins are slower on the cell surface than those in artificial lipid bilayers or blebs. One hypothesis that may partially explain this mystery is the effect of the cytoskeleton structures on the protein dynamics. A model proposed by Kusumi [1] is the Fence-Picket Model which describes the cell membrane as a set of compartment regions, each ~ 10 to 200 nm in size, created by direct or indirect interaction of lipids and proteins with actin filaments just below the membrane. To test this hypothesis, we have assembled a high-speed ...