Life Sciences Commons^™

Link Between Energy Investment In Biosynthesis And Proteostasis: Testing The Cost–Quality Hypothesis In Insects, Taiwo Iromini, Xiaolong Tang, Kyara N. Holloway, Chen Hou

Biological Sciences Faculty Research & Creative Works

The Energy Requirement for Biosynthesis Plays an Important Role in an Organism's Life History, as It Determines Growth Rate, and Tradeoffs with the Investment in Somatic Maintenance. This Energetic Trait is Different between Painted Lady (Vanessa Cardui) and Turkestan Cockroach (Blatta Lateralis) Due to the Different Life Histories. Butterfly Caterpillars (Holometabolous) Grow 30-Fold Faster, and the Energy Cost of Biosynthesis is 20 Times Cheaper, Compared to Cockroach Nymphs (Hemimetabolous). We Hypothesize that Physiologically the Difference in the Energy Cost is Partially Attributed to the Differences in Protein Retention and Turnover Rate: Species with Higher Energy Cost May Have a Lower …

Ubiquitin-Mediated Proteasome Degradation Regulates Optic Fissure Fusion, Warlen Pereira Piedade, Sydney Veith, Jakub Konrad Famulski

Biology Faculty Publications

Optic fissure fusion is a critical event during retinal development. Failure of fusion leads to coloboma, a potentially blinding congenital disorder. Pax2a is an essential regulator of optic fissure fusion and the target of numerous morphogenetic pathways. In our current study, we examined the negative regulator of pax2a expression, Nz2, and the mechanism modulating Nlz2 activity during optic fissure fusion. Upregulation of Nlz2 in zebrafish embryos resulted in downregulation of pax2a expression and fissure fusion failure. Conversely, upregulation of pax2a expression also led to fissure fusion failure suggesting Pax2 levels require modulation to ensure proper fusion. Interestingly, we discovered Nlz2 …

Deciphering The Molecular Mechanism Through Which Rhus Coriaria Exerts Its Anti-Cancer Activity, Khawlah Najib Saeed Athamneh

Dissertations

Cancer remains a major health problem around the globe. Among various types of treatments, plants have been shown to have great capacity in cancer treatment, one of which is Rhus coriaria. Commonly known as sumac, Rhus coriaria is a culinary herb that is known to possess different therapeutic values including anti-oxidant and anti-microbial activities.

In this Ph.D. project, we tested the effect of Rhus coriaria extract (RCE) on the migration, invasion, and metastasis of MDA-MB-231 human breast cancer cells. We showed that non-cytotoxic concentrations of RCE inhibited migration and invasion, blocked adhesion to fibronectin, and downregulated MMP-9. Additionally, we found …

Proteasome Storage Granules Protect Proteasomes From Autophagic Degradation Upon Carbon Starvation, Richard S. Marshall, Richard D. Vierstra

Biology Faculty Publications & Presentations

26S proteasome abundance is tightly regulated at multiple levels, including the elimination of excess or inactive particles by autophagy. In yeast, this proteaphagy occurs upon nitrogen starvation but not carbon starvation, which instead stimulates the rapid sequestration of proteasomes into cytoplasmic puncta termed proteasome storage granules (PSGs). Here, we show that PSGs help protect proteasomes from autophagic degradation. Both the core protease and regulatory particle sub-complexes are sequestered separately into PSGs via pathways dependent on the accessory proteins Blm10 and Spg5, respectively. Modulating PSG formation, either by perturbing cellular energy status or pH, or by genetically eliminating factors required for …

Genetic Interactions Between Bob1 And Multiple 26s Proteasome Subunits Suggest A Role For Proteostasis In Regulating Arabidopsis Development, Elan W. Silverblatt-Buser , '12, Melissa A. Frick , '12, C. Rabeler, Nicholas J. Kaplinsky

Biology Faculty Works

Protein folding and degradation are both required for protein quality control, an essential cellular activity that underlies normal growth and development. We investigated how BOB1, an Arabidopsis thaliana small heat shock protein, maintains normal plant development. bob1 mutants exhibit organ polarity defects and have expanded domains of KNOX gene expression. Some of these phenotypes are ecotype specific suggesting that other genes function to modify them. Using a genetic approach we identified an interaction between BOB1 and FIL, a gene required for abaxial organ identity. We also performed an EMS enhancer screen using the bob1-3 allele to identify pathways that are …

Purification Of 26s Proteasomes And Their Subcomplexes From Plants, Richard S. Marshall, David C. Gemperline, Richard D. Vierstra

Biology Faculty Publications & Presentations

The 26S proteasome is a highly dynamic, multisubunit, ATP-dependent protease that plays a central role in cellular housekeeping and many aspects of plant growth and development by degrading aberrant polypeptides and key cellular regulators that are first modified by ubiquitin. Although the 26S proteasome was originally enriched from plants over 30 years ago, only recently have significant advances been made in our ability to isolate and study the plant particle. Here, we describe two robust methods for purifying the 26S proteasome and its subcomplexes from Arabidopsis thaliana; one that involves conventional chromatography techniques to isolate the complex from wild-type …

Ubiquitin-Mediated Degradation Via Ups And Lysosome, Qizhi Sun

Electronic Thesis and Dissertation Repository

Ubiquitination plays a fundamental role in determining protein fate. Once ubiquitinated, the cargo is directed to the proteasome for partial or complete degradation or lysosome for complete degradation. Failing to eliminate these cargos results in the accumulation of toxic proteins that contribute to neurodegenerative and immunological diseases, cancer and other human maladies. Thus, identifying proteins subject to ubiquitin-mediated degradation and characterizing the mechanisms governing these processes underscores their importance to human health. The calcium/calmodulin-dependent serine protein kinase (CASK) is one such protein that is required for brain development. However, mutations that cause CASK to accumulate are correlated to X-linked mental …

Role Of The Pkna And Pknb Kinases In Mycobacterium Tuberculosis, Tripti Anandan

Wayne State University Dissertations

To respond to environmental changes, M. tuberculosis possesses eleven "eukaryotic-type" Ser/Thr protein kinases. The aim of the study described in this dissertation was to identify role of two of these kinases; PknA and PknB that are essential in M. tuberculosis. Two approaches are described to screen for potential in vivo substrates of PknA/PknB. First approach is based on proteomic search by over-expressing PknA/PknB in M. tuberculosis. Proteomic search led to identification of proteasome to be a substrate of PknA and PknB in M. tuberculosis. Furthermore, I demonstrate that the phosphorylation of PrcA and PrcB by PknA regulates processing of Pre-PrcB. …

The Role Of A Camkii/Pka-Protein Degradation-Glur2 Pathway In The Control Of Memory Updating Following Retrieval, Timothy Jarome

Theses and Dissertations

Reconsolidation is thought to be a process whereby consolidated memories can be modified following retrieval. However, very little is known about the molecular mechanisms that regulate this reconsolidation process. In the present series of experiments we tested if memories "destabilize" or become labile following retrieval through a specific signaling pathway. We found that retrieval of a contextual fear memory differentially increased proteasome activity in the amygdala and hippocampus and resulted in unique changes in AMPA receptor subunit expression in these brain regions. These changes were dependent on CaMKII activity, which was required for increases in Rpt6-S120 phosphorylation, proteasome activity and …

Scfkmd Controls Cytokinin Signaling By Regulating The Degradation Of Type-B Response Regulators, Hyo Jung Kim, Yi-Hsuan Chiang, Joseph J. Kieber, G. Eric Schaller

Dartmouth Scholarship

Cytokinins are plant hormones that play critical roles in growth and development. In Arabidopsis, the transcriptional response to cytokinin is regulated by action of type-B Arabidopsis response regulators (ARRs). Although central elements in the cytokinin signal transduction pathway have been identified, mechanisms controlling output remain to be elucidated. Here we demonstrate that a family of F-box proteins, called the kiss me deadly (KMD) family, targets type-B ARR proteins for degradation. KMD proteins form an S-phase kinase-associated PROTEIN1 (SKP1)/Cullin/F-box protein (SCF) E3 ubiquitin ligase complex and directly interact with type-B ARR proteins. Loss-of-function KMD mutants stabilize type-B ARRs and exhibit an …

Role Of Phosphoylation Of The Mycobacterium Tuberculosis Proteasome In Oxidative Stress Response And Regulation Of Homoserine Kinase (Thrb) In Corynebacterium Glutamicum, Heather Baun

Wayne State University Theses

Part 1:

One-third of the world's population is infected with the latent form of Mycobacterium tuberculosis. M. tuberculosis must be able to control this latent even in response to nitrosative and oxidative stress conferred by the host. It is not well known how M. tuberculosis controls this state.

One possibility for this control is through its eleven eukaryotic-like serine/threonine protein kinases. Our lab has focused research on two eukaryotic-like ser/thr protein kinases, PknA and PknB. It has been found that PknA expression may affect the stability or the assembly of the proteasome complex, which is essential for M. tuberculosis to …

The Involvement Of 26s Proteasome Complex In Selenium Toxicity, Melissa Sabbagh

Honors Theses

Plants that hyperaccumulate elements like selenium to potentially toxic levels may use proteasome complexes to reduce toxicity. The 26S proteasome complex may be a pathway that these plants take to rid themselves of selenium toxicity by destroying damaged proteins caused by selenium. A method to test this hypothesis is to use a hyperaccumulator of selenium Stanleya pinnata and nonhyperaccumulators Populous tremula and Arabdopsis thaliana to evaluate their proteasome abundance without and with selenium. To compare these species western blots were made to show the differences in proteasome abundance. Also to compare the amount of oxidized and an ubiquinated protein in …

The Role Of S7, A Subunit Of The 19s Proteasome, In The Transcriptional Regulation Of Mhc Ii., Dawson Gerhardt

Biology Theses

Induction of an adaptive, or antigen specific, immune response is critical for eliminating most infections. Pathogen clearance is accomplished primarily, by the actions of CD4+ T cells through their ability to recognize foreign antigens presented at the cell surface by major histocompatibility class II (MHC II) molecules. Consequently, the capacity to regulate expression of MHC molecules is essential to control the adaptive immune response. MHC molecules are regulated at the level of transcription by a master regulator, the class II transcriptional activator, CIITA. Thus, the expression of MHC II is directly related to proper CIITA activity. This thesis focuses on …

The Saccharomyces Cerevisiae Ubiquitin-Proteasome System, Mark Hochstrasser, Phoebe Johnson, Cassandra Arendt, Alexander Amerik, Sowmya Swaminathan, Rob Swanson, Shyr-Jiann Li, Jeffrey Laney, Robin Pals-Rylaarsdam, Jonathan Nowak, Pamela Connerly, M. Yanagida, K. Nasmyth, M. Tyers, R. Hunt, J. Diffley

Rob Swanson

Our studies of the yeast ubiquitin-proteasome pathway have uncovered a number of general principles that govern substrate selectivity and proteolysis in this complex system. Much of the work has focused on the destruction of a yeast transcription factor, MAT alpha 2. The alpha 2 protein is polyubiquitinated and rapidly degraded in alpha-haploid cells. One pathway of proteolytic targeting, which depends on two distinct endoplasmic reticulum-localized ubiquitin-conjugating enzymes, recognizes the hydrophobic face of an amphipathic helix in alpha 2. Interestingly, degradation of alpha 2 is blocked in a/alpha-diploid cells by heterodimer formation between the alpha 2 and a1 homeodomain proteins. The …