Word (http://tools.niehs.nih.gov/portfolio/sc/list_doc.cfm?ext=.doc)
|
Excel (http://tools.niehs.nih.gov/portfolio/sc/list_xls.cfm?ext=.xls)
|
PDF (http://tools.niehs.nih.gov/portfolio/sc/list_doc.cfm?pdf=1&ext=.pdf)
Record Count: 6
To sort columns alphabetically or numerically, click on the column
header (Title, Principal Investigator, Institution, City, ST, Award Code, or
Pubs).
DESCRIPTION (provided by applicant): Organisms employ multiple conserved pathways to repair different types of DNA lesions. One important pathway is transcription coupled repair (TCR), which is responsible for rapid repair in the transcribed strand of an active gene. Defective TCR gives rise to the severe human disorder Cockayne's syndrome, and possibly other as yet unidentified diseases. Rpb9, a nonessential subunit of RNA polymerase II (Pol II), was recently found to mediate a TCR subpathway, which is superimposed on the Rad26 mediated TCR subpathway in Pol II transcribed genes. Rpb4, another nonessential subunit of Pol II, may play a dual role in regulating the two TCR subpathways, suppressing the Rpb9 mediated TCR and facilitating the Rad26 mediated TCR. The domains and critical residues of Rpb9 required for mediating TCR will be mapped by systematically deleting residues from the N- and C-termini, and by replacing certain critical residues. Other proteins involved in Rpb9 mediated TCR will be pulled down by epitope tagged Rpb9 or Rad14. The proteins pulled down will be identified by mass spectrometry analysis, and characterized genetically and biochemically. Yeast two hybrid system may also be utilized to screen potential proteins involved in Rpb9 mediated TCR. Covalent modifications of the largest subunit of Pol II in response to DNA damage may serve as TCR signals. Defl has been shown to be involved in ubiquitination and degradation of Pol II under certain TCR circumstances. The roles of Rpb9 and Defl in the covalent modifications of the largest subunit of Pol II will be examined by using Western blot analysis. The domains of Rpb4 required for suppressing Rpb9 mediated TCR will be mapped by systematically deleting residues from different regions of the protein. Rpb7 is an essential subunit of Pol II and forms complex with Rpb4. The role of Rpb7 in suppressing Rpb9 mediated TCR will be examined by controlling its expression levels in the cell. Deletion of SPT4 has been shown to alleviate the requirement of Rad26 for TCR. The possible role of Spt4 in suppressing Rpb9 mediated TCR will be studied by deleting the gene in cells with different TCR subpathways operative. Multiple components may be involved in the regulation of the two TCR subpathways. The roles of gene elements in the regulation will be examined by systematically creating deletions and mutations of these elements. Furthermore, how transcription levels and the transcription activator Gal4 may be involved in the regulation will also be investigated.
Crisp Terms/Key Words: molecular assembly /self assembly, fungal protein, DNA damage, protein structure function, ubiquitin, posttranslational modification, phosphorylation, DNA directed RNA polymerase, DNA repair, intermolecular interaction, fungal genetics, genetic transcription, genetic regulation, genetic regulatory element, Saccharomyces cerevisiae, mass spectrometry
DESCRIPTION (provided by applicant): The long-term objective of this proposal is to supply information that will aid in identifying conditions under which individuals may be susceptible to alkylbenzene-induced toxicity. Alkylbenzenes are produced in extensive quantities throughout the world. Simple aromatic hydrocarbons (e.g. benzene, toluene, and ethylbenzene) are major components of unleaded gasoline and are also used in the production of a wide variety of consumer products. The P450 system is responsible for both aliphatic and aromatic hydroxylation of the aromatic hydrocarbons, with several forms, CYP1A2, CYP2B4, and CYP2E1, being implicated in hydrocarbon metabolism. The toxicity from many of the hydrocarbons is known to be due to bioactivation of a small percentage of the parent compound to reactive intermediates. This process requires a functional interaction between P450 and the flavoprotein NADPH-cytochrome P450 reductase. However, total P450 levels exceed those of reductase by a ratio of 20:1. In addition, there are multiple forms of P450, each having their own reductase binding characteristics and substrate dependencies. This raises the question: "How does a single reductase supply electrons to all the P450s?" A second question is: "Can one P450 influence the function of a second P450?" The proposed studies are designed to address questions related to the organization of P450 and reductase, focusing on the metabolism of alkylbenzenes. During the prior grant period, we identified important interactions among CYP2B4, CYP1A2 and reductase that have a substantial effect on substrate metabolism. The results are consistent with the formation of a CYP1A2-CYP2B4 complex having unusual reductase binding characteristics. We now propose to characterize these interactions, and to identify the region(s) responsible for the interactions among these proteins. We also intend to examine P450-P450 interactions in the CYP2E1/CYP1A2/reductase, and CYP2E1/CYP2B4/reductase systems, and to focus on the ability of these interactions to alter not only metabolism of hydrocarbons and other substrates, but also generation of reactive oxygen. These studies will increase our understanding of how the P450 electron transport chain is organized, and will provide new important information on the role of the P450 system in the bioactivation of aromatic hydrocarbons and the generation of reactive oxygen - a process that can have a significant influence on chemical toxicity.
DESCRIPTION (provided by applicant): Embryonic exposure to nicotine has deleterious consequences on human development at various levels. Such exposure can lead to long term changes in the cognitive abilities and behaviors related to learning and memory. Many mammalian models have been employed to understand how nicotine can exert such effects, but this is difficult because most mammalian behaviors and the nervous system underlying them are complex. We are studying the effects of nicotine exposure in a model vertebrate, the zebrafish, with the goal of linking behavioral abnormalities created by nicotine exposure to developmental alterations in spinal neurons and associated spinal musculature. Zebrafish embryos are sensitive to nicotine exposure (Svoboda et. al, 2002). Embryos acutely exposed to nicotine exhibit a swimming-like behavior at time when they typically do not swim. On the other hand, chronically exposing embryos to nicotine, results in paralysis. These two behavioral phenotypes point us toward candidate cell types that may be altered in zebrafish by embryonic nicotine exposure. In this proposal the consequences of embryonic nicotine exposure on spinal neurons and associated musculature will be determined. To our knowledge, this is the first attempt at utilizing the zebrafish model to understand the consequences of embryonic nicotine exposure. The aims are: 1) To systematically identify and characterize all of the zebrafish nAChRs, 2) to determine the consequences of nicotine exposure on motoneuron and muscle development at the mechanistic level, 3) to determine the consequences of nicotine exposure on embryonic sensory neuron development at the mechanistic level, 4) To determine if phenotypes that arise form transient embryonic nicotine exposure persist into adulthood. Each of these aims addresses a fundamental issue relating to how exogenous nicotine potentially exerts its effects during vertebrate development. First, they describe behavioral and neuroanatomical phenotypes that result from early embryonic exposure to nicotine. Secondly, they provide mechanistic insight into how those phenotypes could arise. The work is basic research in developmental neurotoxicology. It serves to establish a foundation whereby zebrafish can be utilized in vivo to unravel the mechanisms that underlie the effects of nicotine exposure during development.
DESCRIPTION (provided by applicant):
The occurrence of inflammatory respiratory diseases, such as asthma, has increased dramatically in the past decade. This rate of increase is more than can be accounted for by genetic drift alone and suggests a role for the environment. Many hypotheses attempt to explain this phenomenon by citing better hygiene, environmental pollution, viral respiratory tract infections, and/or loss of some protective effect found in a rural lifestyle as culprits in disease initiation and exacerbation. This proposal seeks to determine if exposure during early neonatal life to ultrafine particles (PM0.1) typically produced from thermal remediation of hazardous wastes leads to predisposition, development of, or exacerbation of allergic respiratory disease in the adult. Our hypothesis is that PM0.1 generated from the combustion/thermal degradation of hazardous wastes contains persistent, surface-stabilized free radicals that in neonates interact with epithelial-mucosal surfaces and modulate the adaptive immune response leading to adult airways disease such as asthma. In the short term, this proposal will explore the validity of this hypothesis by accomplishing the following specific aims: 1) characterize the ability of PM0.1 to produce oxidative stress within the lung using biochemical and proteomic approaches; 2) define the impact of PM0.1 on pulmonary pathophysiology of neonatal rats; and 3) elucidate the cellular and molecular events by which PM0.1-induced increases in reactive oxygen species lead to pulmonary and/or immune dysfunction in adults. The long-term objective of our laboratory is to realize the initiators of the immunological and pathophysiological changes that occur during the early stages of pulmonary airways disease and ultimately to understand the fundamental causes of asthma so that more effective interventions and therapy may be developed. Completion of the proposed studies will provide insight into how combustion/thermal degradation of waste affects the development of inflammatory airways disease in children with the expectation of valid extrapolation to human inflammatory airways disease, such as asthma. The outcome of these studies will not only have important implications for public health but also for public environmental policy, since currently there are no air quality standards for PM0.1.
DESCRIPTION (provided by applicant)
The proposed project will implement Minority Worker Training Programs in Baton Rouge, La (Southern University at Baton Rouge), New Orleans, LA (Deep South Center for Environmental Justice at Xavier University), Houston, TX (Texas Southern University), Biloxi/Gulfport, MS (Center for Environmental and Economic Justice), and Savannah, GA (Harambee House/Center for Environmental Justice). The total cost for the initial budget period is $1,384,755. The project has two main goals: 1) to work in partnership with historically Black colleges/universities (HBCUs), unions via apprenticeship programs, local community-based organizations, local community colleges, and minority-owned training providers to implement a quality, comprehensive worker training program that will address environmental remediation efforts in areas in close proximity to the communities from which participants will be recruited, selected, trained, and placed into employment; and 2) to assist HBCUs, community colleges, and community-based organizations in promoting worker health and safety through education and training. The participants will be recruited and selected from communities along the Mississippi River Chemical Corridor (including East Baton Rouge parish and New Orleans), and targeted neighborhoods in Houston, TX, Biloxi/Gulfport, MS, and Savannah, GA, that are in close proximity to hazardous waste sites and encompass a population of low-income minority residents. The participants will be 18 years of age or older, and must be unemployed or underemployed. The training will provide selected participants with the skills needed to obtain sustainable employment with contractors working on remediation. The training program will include, 1) basic skills training (life skills, job readiness, study skills, physical fitness, mathematics, computer basics, and counseling); 2) technical training in construction, hazardous waste removal, lead and asbestos abatement, mold remediation, and hazardous waste transporter/CDL preparation (for selected trainees); and 3) job development/job placement assistance.
|