Biochemistry Commons^™

The Role Of The Androgen Receptor Cofactor P44/Wdr77 In Astrocyte Activation, Bryce H. Vincent

Dissertations and Theses (Open Access)

Astrogliosis is induced by neuronal damage and is also a pathological feature of the major aging-related neurodegenerative disorders. The mechanisms that control the cascade of astrogliosis have not been well established. In a previous study, we identified a novel androgen receptor (AR)-interacting protein (p44/WDR77) and found that it plays a critical role in the control of proliferation and differentiation of prostate epithelial cells. In the present study, we found that deletion of the p44 gene in the mouse brain caused accelerated aging with dramatic astrogliosis. The p44/WDR77 is expressed in astrocytes and loss of p44/WDR77 expression in astrocytes leads to …

Altering Nitric Oxide Bioavailability And Lipid Profiles In Endothelial Cells By Polycyclic Aromatic Hydrocarbons In Particulate Matter, Liang Yu

Theses and Dissertations in Biomedical Sciences

Epidemiologic studies have demonstrated a significant association between exposure to particulate matter (PM) and atherosclerosis. Polycyclic aromatic hydrocarbons (PAHs) present in particulate matter, are well known to induce oxidative stress and lipid peroxidation via generation of reactive oxygen species (ROS). Lipid peroxidation involves regulating endothelial nitric oxide synthase via inhibition of its activity, and as a result, mediates dilation of coronary arterioles is involved with the pathogenesis of atherosclerosis. However, data on assessment of oxidized lipid formation is limited due to low resolution of mass spectrometer methods. Taking the advantage of a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR-MS) …

The Role And Mechanism Of The Homeobox Gene Dlx4 In Transforming Growth Factor-B Resistance In Cancer, Bon Q. Trinh

Dissertations and Theses (Open Access)

Transforming growth factor-b (TGF-b) is a cytokine that plays essential roles in regulating embryonic development and tissue homeostasis. In normal cells, TGF-b exerts an anti-proliferative effect. TGF-b inhibits cell growth by controlling a cytostatic program that includes activation of the cyclin-dependent kinase inhibitors p15^Ink4B and p21^WAF1/Cip1 and repression of c-myc. In contrast to normal cells, many tumors are resistant to the anti-proliferative effect of TGF-b. In several types of tumors, particularly those of gastrointestinal origin, resistance to the anti-proliferative effect of TGF-b has been attributed to TGF-b receptor or Smad mutations. However, these mutations are absent from many …

A Novel Function For Aurora B Kinase In The Regulation Of P53 By Phosphorylation, Chris P. Gully

Dissertations and Theses (Open Access)

The mitotic kinase Aurora B plays a pivotal role in mitosis and cytokinesis and governs the spindle assembly checkpoint which ensures correct chromosome segregation and normal progression through mitosis.  Aurora B is overexpressed in breast and other cancers and may be an important molecular target for chemotherapy.  Tumor suppressor p53 is the guardian of the genome and an important negative regulator of the cell cycle. Previously, it was unknown whether Aurora B and p53 had mutual regulation during the cell cycle.  A small molecule specific inhibitor of Aurora B, AZD1152, gave us an indication that Aurora B negatively impacted p53 …

The Release Of Calcium In Bacillus Anthracis Pathogenicity Methods, Natiera Magnuson, Manomita Patra Bhowmik, Maria Elena Reynaga, Ernesto Abel-Santos

Festival of Communities: UG Symposium (Posters)

Anthrax infection starts with germination of Bacillus anthracis spores in macrophages. Some bacteria, including B. anthracis, can sporulate in response to environmental stress, such as starvation. During germination, large concentrations of calcium ions are released from the B. anthracis spore. Calcium ions are hydrophilic secondary messengers, and may therefore interfere with detection of the spore by confusing the cell signaling pathways. We investigated calcium release on infected macrophage viability by replacing the calcium stored in B. anthracis spores for other cations via demineralization/remineralization. It was discovered that calcium ions typically out-performed other cations in germination of B. anthracis.

Structural Study Of Mcry2: A Circadian Rhythm Regulator, Brenda L. Rodarte^, Gustavo A. Avila, Adrian S. Enriquez, Nicolas D. Silva, Tiffany H. Blankenship, Erquan Eric Zhang*, Chuan Xiao*

COURI Symposium Abstracts, Spring 2011

A circadian clock is a 24 hour biological rhythm that regulates physiological, psychological and behavioral processes in living organisms. Understanding the regulation mechanism of such circadian rhythms can have great impact in certain diseases such as sleeping disorders and cancers. There are many genes regulating circadian rhythms in different species. Cryptochromes (CRY) are photosensory receptors mediating light regulation of growth and development in certain species. Mouse cryptochrome protein mCRY2 has been found to encode a blue light photoreceptor and is important for mice circadian rhythm. The main goal of the project is to determine the atomic structure of mCRY2, via …

An Apoptosis Targeted Stimulus With Nanosecond Pulsed Electric Fields (Nspefs) In E4 Squamous Cell Carcinoma, Wei Ren, Stephen J. Beebe

Bioelectrics Publications

Stimuli directed towards activation of apoptosis mechanisms are an attractive approach to eliminate evasion of apoptosis, a ubiquitous cancer hallmark. In these in vitro studies, kinetics and electric field thresholds for several apoptosis characteristics are defined in E4 squamous carcinoma cells (SCC) exposed to ten 300 ns pulses with increasing electric fields. Cell death was [95% at the highest electric field and coincident with phosphatidylserine externalization, caspase and calpain activation in the presence and absence of cytochrome c release, decreases in Bid and mitochondria membrane potential (Δψm) without apparent changes reactive oxygen species levels or in Bcl2 and Bclxl levels. …

The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff

Honors Theses

Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of …

An Upper Limit For Macromolecular Crowding Effects, Andrew C. Miklos, Congang Li, Courtney D. Sorell, L. Andrew Lyon, Gary J. Pielak

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Solutions containing high macromolecule concentrations are predicted to affect a number of protein properties compared to those properties in dilute solution. In cells, these macromolecular crowders have a large range of sizes and can occupy 30% or more of the available volume. We chose to study the stability and ps-ns internal dynamics of a globular protein whose radius is similar to 2 nm when crowded by a synthetic microgel composed of poly(N-isopropylacrylamide-co-acrylic acid) with particle radii of similar to 300 nm.

Results: Our studies revealed no change in protein rotational or ps-ns backbone dynamics and only mild …

Loss Of Bloom Syndrome Protein Causes Destabilization Of Genomic Architecture And Is Complemented By Ectopic Expression Of Escherichia Coli Recg In Human Cells, Michael Wayne Killen

University of Kentucky Doctoral Dissertations

Genomic instability driven by non-allelic homologous recombination (NAHR) provides a realistic mechanism that could account for the numerous chromosomal abnormalities that are hallmarks of cancer. We recently demonstrated that this type of instability could be assayed by analyzing the copy number variation of the human ribosomal RNA gene clusters (rDNA). Further, we found that gene cluster instability (GCI) was present in greater than 50% of the human cancer samples that were tested. Here, data is presented that confirms this phenomenon in the human GAGE gene cluster of those cancer patients. This adds credence to the hypothesis that NAHR could be …

Identification And Characterization Of Fkbp52-Specific Inhibitors For The Treatment Of Prostate Cancer, Johanny Tonos De Leon

Open Access Theses & Dissertations

Steroid hormone receptors require the ordered assembly of various chaperone and cochaperone proteins in order to reach a functional state. The final stage in the receptor maturation process requires the formation of a mutimeric complex consisting of Hsp90 dimer, p23, and one of several large immunophilins. Studies conducted previously demonstrated that the large immunophilin FKBP52 acts to potentiate glucocorticoid, androgen, and progesterone receptor signaling pathways. The aim of these studies was to identify and characterize FKBP52-specific inhibitors that would not only serve as tools for the pharmacological analysis of FKBP52-receptor interactions, but may also lead to novel drugs with significant …

Cardiac Calsequestrin Phosphorylation And Trafficking In The Mammalian Cardiomyocyte, Timothy Mcfarland

Wayne State University Dissertations

Cardiac CSQ (CSQ2) is a multifaceted protein, capable of binding significant quantities of Ca2+ and altering ryanodine receptor activity at the junctional sarcoplasmic reticulum (SR). Little is known about the trafficking of CSQ2 from its unknown site of biosynthesis, which appears to be of importance as its structure changes in a trafficking-dependent manner in various types of heart failure. Through the use of multiple antibodies specific to classic rough ER markers, and with the creation of CSQ-DsRed tetramer fusion protein, we were able to establish a juxtanuclear localization of rough ER in cardiomyocytes. Using fluorescence confocal microscopy, the translocon complex …

Role Of Protein Kinase C-Iota In Glioblastoma, Shraddha R. Desai

USF Tampa Graduate Theses and Dissertations

The focus of this research was to investigate the role of protein kinase C-iota (PKC-é) in the regulation of Bad function, a pro-apoptotic member of the Bcl-2 family and Cdk7 function, a master cell cycle regulator in glioblastoma.

The results were obtained from the human glial tumor derived cell lines, T98G and U87MG. In these cells, PKC-é co-localized and directly associated with Bad as shown by immunofluorescence, immunoprecipitation, and Western blotting. Furthermore, in-vitro kinase activity assay showed that PKC-é directly phosphorylated Bad at phospho specific residues, S112, S136 and S155 which in turn induced inactivation of Bad and disruption of …

Role Of Protein Kinase C-Iota In Neuroblastoma And The Effect Of Ica-1, A Novel Protein Kinase C-Iota Inhibitor On The Proliferation And Apoptosis Of Neuroblastoma Cells, Prajit P. Pillai

USF Tampa Graduate Theses and Dissertations

Protein Kinase C-iota (PKC-é), an atypical protein kinase C isoform manifests its potential as an oncogene by targeting various aspects of cancer cells such as growth, invasion and survival. PKC-é confers resistance to drug-induced apoptosis in cancer cells. The acquisition of drug resistance is a major obstacle to good prognosis in neuroblastoma. The focus of the dissertation was three-fold: First to study the role of PKC-é in the proliferation of neuroblastoma. Secondly, to identify the efficacy of [4-(5-amino-4-carbamoylimidazol-1-yl)-2,3-dihydroxycyclopentyl] methyl dihydrogen phosphate (ICA-1) as a novel PKC-é inhibitor in neuroblastoma cell proliferation and apoptosis. Finally, to analyze whether PKC-é could self-regulate …

Production, Purification And Crystallization Of Membrane Integrated Multimeric Bax, Adelbert Mark Villoso

UNLV Theses, Dissertations, Professional Papers, and Capstones

Apoptosis, or programmed cell death, is a vital process intimately involved in the embryonic development and homeostatic maintenance of all multicellular organisms. The committing step to apoptosis is regulated by a key protein, Bax, and its ability to integrate and form a pore structure at the outer mitochondrial membrane.

Unfortunately, the molecular details of apoptosis remain largely unclear due to the lack of structural data of integral membrane (IM) Bax. Experimental limitations of membrane protein production have slowed the pursuit of an IM-Bax structure simply because standard protocols for producing recombinant IM-Bax are inefficient in producing adequate quantities of IM-Bax …

Virulence Of An Emerging Respiratory Pathogen, Genus Pandoraea, In Vivo And Its Interactions With Lung Epithelial Cells, Gillian Herbert, Anne Costello, Lydia Fabunmi, Kirsten Schaffer, Kevin Kavanagh, Emma M. Caraher, Máire Callaghan, Siobhan Mcclean

Articles

Pandoraea species have emerged as opportunistic pathogens among cystic fibrosis (CF) and non-CF patients. Pandoraea pulmonicola is the predominant Pandoraea species among Irish CF patients. The objective of this study was to investigate the pathogenicity and potential mechanisms of virulence of Irish P. pulmonicola isolates and strains from other Pandoraea species. Three patients from whom the P. pulmonicola isolates were isolated have since died. The in vivo virulence of these and other Pandoraea strains was examined by determining the ability to kill Galleria mellonella larvae. The P. pulmonicola strains generally were the most virulent of the species tested, with three …

Characterization Of Metastasis-Associated Cell Surface Glycoproteins In Prostate Cancer, Lifang Yang

Theses and Dissertations in Biomedical Sciences

Prostate cancer (PCa) is a major health problem in males in the United States. Its lethality is mostly attributed to the primary tumor metastasizing to distant sites that are highly resistant to conventional therapies. Serum Prostate Specific Antigen (PSA) is the only protein biomarker used in clinic for prediction of prostate cancer recurrence following local therapies. Nonetheless, PSA lacks the ability to predict the behavior of an individual tumor in an individual patient. Therefore, development of reliable biomarkers for detection of metastatic potential in primary tumors, as well as discovery of new therapeutic targets, is in a great need for …

Release Of Hmgb1 In Response To Pro-Apoptotic Glioma Killing Strategies: Efficacy And Neurotoxicity, Marianela Candolfi, Kader Yagiz, David Foulad, Gabrielle Alzadeh, Matthew Tesarfreund, Akm Ghulam Muhammad, Mariana Puntel, Kurt Kroeger, Chunyan Liu, Sharon Lee, James Curtin, Gwendalyn D. King, Jonathan Lerner, Katsuaki Sato, Yohei Mineharu, Weidong Xiong, Pedro R. Lowenstein, Maria Castro

Articles

Purpose In preparation for a Phase I clinical trial utilizing a combined cytotoxic/immunotherapeutic strategy using adenoviruses expressing Flt3L (Ad-Flt3L) and thymidine kinase (Ad-TK) to treat glioblastoma (GBM), we tested the hypothesis that Ad-TK+GCV would be the optimal tumor killing agent in relation to efficacy and safety when compared to other pro-apoptotic approaches. Experimental Design and Results The efficacy and neurotoxicity of Ad-TK+GCV was compared with Ads encoding the pro-apoptotic cytokines (TNF-α, TRAIL, FasL), alone or in combination with Ad-Flt3L. In rats bearing small GBMs (day 4), only Ad-TK+GCV or Ad-FasL improved survival. In rats bearing large GBMs (day 9), the …

Glycopeptidome Of A Heavily N-Glycosylated Cell Surface Glycoprotein Of Dictyostelium Implicated In Cell Adhesion, Christa L. Feasley, Jennifer M. Johnson, Christopher M. West, Catherine P. Chia

School of Biological Sciences: Faculty Publications

Genetic analysis has implicated the cell surface glycoprotein gp130 in cell interactions of the social amoeba Dictyostelium, and information about the utilization of the 18 N-glycosylation sequons present in gp130 is needed to identify critical molecular determinants of its activity. Various glycomics strategies, including mass spectrometry of native and derivatized glycans, monosaccharide analysis, exoglycosidase digestion, and antibody binding, were applied to characterize a nonanchored version secreted from Dictyostelium. s-gp130 is modified by a predominant Man8GlcNAc4 species containing bisecting and intersecting GlcNAc residues and additional high-mannose N-glycans substituted with sulfate, methyl-phosphate, and/or core R3-fucose. Site mapping confirmed the occupancy …

The Ubiquitin Ligase Ube4b Is Required For Efficient Epidermal Growth Factor Receptor Degradation, Natalie Sirisaengtaksin

Dissertations and Theses (Open Access)

The length of time that integral membrane proteins reside on the plasma membrane is regulated by endocytosis, a process that can inactivate these proteins by removing them from the membrane and may ultimately result in their degradation. Proteins are internalized and pass through multiple distinct intracellular compartments where targeting decisions determine their fate. Membrane proteins initially enter early endosomes, and subsequently late endosomes/multivesicular bodies (MVBs), before being degraded in the lysosome. The MVB is a subset of late endosomes characterized by the appearance of small vesicles in its luminal compartment. These vesicles contain cargo proteins sorted from the limiting membrane …

The Rho Family Gtpase: Determining Gef Specificity Through Recombinant Expression, Farrah Steinke

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Very-Long-Chain Fatty Acids Are Involved In Polar Auxin Transport And Developmental Patterning In Arabidopsis, Françoise Roudier, Lionel Gissot, Frédéric Beaudoin, Richard Haslam, Louise V. Michaelson, Jessica Marion, Diana Molino, Amparo Lima, Liên Bach, Halima Morin, Frédérique Tellier, Jean-Christophe Palauqui, Yannick Bellec, Charlotte Renne, Martine Miquel, Marco Dacosta, Julien Vignard, Christine Rochat, Jennifer E. Markham, Patrick Moreau, Jonathan Napier, Jean-Denis Faure

Department of Biochemistry: Faculty Publications

Very-long-chain fatty acids (VLCFAs) are essential for many aspects of plant development and necessary for the synthesis of seed storage triacylglycerols, epicuticular waxes, and sphingolipids. Identification of the acetyl-CoA carboxylase PASTICCINO3 and the 3-hydroxy acyl-CoA dehydratase PASTICCINO2 revealed that VLCFAs are important for cell proliferation and tissue patterning. Here, we show that the immunophilin PASTICCINO1 (PAS1) is also required for VLCFA synthesis. Impairment of PAS1 function results in reduction of VLCFA levels that particularly affects the composition of sphingolipids, known to be important for cell polarity in animals. Moreover, PAS1 associates with several enzymes of …

Phosphorylation Of The Glycine Transporter 1, Javier Vargas Medrano

Open Access Theses & Dissertations

The extracellular levels of the neurotransmitter glycine in the brain are tightly regulated by the high-affinity glycine transporter 1 (GlyT1) and the clearance of glycine depends on its rate of transport and the levels of cell surface GlyT1. Over the past years, it has been shown that PKC activation diminishes the activity and promoted phosphorylation of several neurotransmitter transporters including the dopamine, serotonin and norepinephrine transporters however, its role is unknown for the glycine transporter. To get insights into the role of PKC activation on GlyT1 regulation, we used three N-terminus GlyT1 isoforms stably expressed in porcine aortic endothelial (PAE) …

Cloning Of "Animal Cryptochrome" Cdna From The Model Organism Chlamydomonas Reinhardtii For Functional Analysis Of Its Protein Product, Shobha Lavanya Silparasetty

Masters Theses & Specialist Projects

reinhardtii, a unicellular green alga, is a model organism to study the circadian clock. Cryptochromes are the blue light photoreceptors that entrain the clock in some organisms. The CPH1 protein of C. reinhardtii resembles the cryptochromes of the plant model Arabidopsis, but whether CPH1 entrains the circadian clock in C. reinhardtii is not yet known. Recent reports have suggested the existence of one more cryptochrome in C. reinhardtii, which resembles the cryptochromes of animals. However, the amino acid sequence of this protein shows even higher sequence similarity with the 6-4 DNA photolyase of Arabidopsis. DNA photolyases …

Characterization And Functional Regulation Of Bioactive Peptides In Avian Macrophages And Heterophils, Lakshmi Kannan

Graduate Theses and Dissertations

Oligopeptides and low molecular weight polypeptides play central roles as effectors and signal transducers acting as hormones, neurotransmitters, growth factors, toxins, and antimicrobial factors that are important for the survival of the organism. Owing to the ubiquitous involvement of peptides in many key regulatory processes, we have been interested to identify native peptides in different cells and tissues and understand their functions. To conduct our studies, we used avian macrophages and heterophils as models of specialized cells which constitute central components of innate immunity. These studies involved (a) qualitative identification and characterization of the peptides associated with high intensity mass …

Integral Membrane Proteins Brr6 And Apq12 Link Assembly Of The Nuclear Pore Complex To Lipid Homeostasis In The Endoplasmic Reticulum, Christine A. Hodge, Vineet Choudhary, Michael J. Wolyniak, John J. Scarcelli, Roger Schneiter, Charles N. Cole

Dartmouth Scholarship

Cells of Saccharomyces cerevisiae lacking Apq12, a nuclear envelope (NE)-endoplasmic reticulum (ER) integral membrane protein, are defective in assembly of nuclear pore complexes (NPCs), possibly because of defects in regulating membrane fluidity. We identified BRR6, which encodes an essential integral membrane protein of the NE-ER, as a dosage suppressor of apq12 Delta. Cells carrying the temperature-sensitive brr6-1 allele have been shown to have defects in nucleoporin localization, mRNA metabolism and nuclear transport. Electron microscopy revealed that brr6-1 cells have gross NE abnormalities and proliferation of the ER. brr6-1 cells were hypersensitive to compounds that affect membrane biophysical properties and to …

Hmgb1 Mediates Endogenous Tlr2 Activation And Brain Tumor Regression, James Curtin, Naiyou Liu, Marianela Candolfi, Weidong Xiong, Hikmat Assi, Kader Yagiz, Matthew Edwards, Kathrin Michelsen, Kurt Kroeger, Chunyan Liu, Akm Ghulam Muhammad, Mary Clark, Moshe Arditi, Begonya Comin-Anduix, Antoni Ribas, Pedro Lowenstein, Maria Castro

Articles

BACKGROUND: Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling …

Hydroxyl Radical Is Produced Via The Fenton Reaction In Submitochondrial Particles Under Oxidative Stress: Implications For Diseases Associated With Iron Accumulation, Carin Thomas, Melissa M. Mackey, Amy A. Diaz, David P. Cox

All Faculty Scholarship for the College of the Sciences

Mitochondrial dysfunction and reactive oxygen species (ROS) are often implicated in diseases involving oxidative stress and elevated iron. As mitochondria produce ATP by oxidative phosphorylation, ROS by-products are generated from the electron transport chain. Although superoxide and hydrogen peroxide have been thoroughly investigated, little evidence documents hydroxyl radical (HO•) production in mitochondria. In order to determine whether HO• is generated under oxidative stress conditions by a Fenton-type mechanism, bovine heart submitochondrial particles were examined for HO• in the presence and absence of iron ligands, antioxidant enzymes and HO• scavengers. HO• was measured as 2,3- and 2,5-dihydroxybenzoic acid (DHBA), using HPLC …

Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eight years after the lamentable anthrax attacks, major scientific effort continues to be done, in order to stop imminent acts of bioterrorism. Innovative ways of therapy against the anthrax disease are being investigated. B. anthracis, the etiological agent of the infection, has a dormant stage in its life cycle known as the endospore. When conditions become favorable spores germinate, transforming into vegetative bacteria. In inhalational anthrax, the most fatal manifestation of the disease, spores enter the organism through the respiratory track, and are phagocytosized by alveolar macrophages of the lungs. Spores are able to sense nutrient availability, activating their germination …

An Inositolphosphorylceramide Synthase Is Involved In Regulation Of Plant Programmed Cell Death Associated With Defense In Arabidopsis, Wenming Wang, Xiaohua Yang, Samantha Tangchiaburana, Roland Ndeh, Jennifer E. Markham, Yoseph Tsegaye, Teresa M. Dunn, Guo-Liang Wang, Maria Bellizzi, James F. Parsons, Danielle Morrissey, Janis E. Bravo, Daniel V. Lynch, Shunyuan Xiao

Department of Biochemistry: Faculty Publications

The Arabidopsis thaliana resistance gene RPW8 triggers the hypersensitive response (HR) to restrict powdery mildew infection via the salicylic acid–dependent signaling pathway. To further understand how RPW8 signaling is regulated, we have conducted a genetic screen to identify mutations enhancing RPW8-mediated HR-like cell death (designated erh). Here, we report the isolation and characterization of the Arabidopsis erh1 mutant, in which the At2g37940 locus is knocked out by a T-DNA insertion. Loss of function of ERH1 results in salicylic acid accumulation, enhanced transcription of RPW8 and RPW8-dependent spontaneous HR-like cell death in leaf tissues, and reduction in plant stature. …