2001 — 2005 |
Filtz, Theresa M |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Determinants of Phospholipase C-Beta Regulation @ Oregon State University
Stimulation of inositol phospholipid hydrolysis is the initial intracellular response to transmembrane receptor activation by a wide array of extracellular chemical signaling messengers. Inositol phospholipid hydrolysis is stimulated by most extracellular signaling molecules through G protein subunits which activate phospholipase C-beta (PLC-beta) enzymes. Further regulation (e.g. inhibition) of inositol phospholipid hydrolysis may be mediated by alternative factors including covalent modification and proximity to membrane bound substrate. This project's long-term goal is an accurate, rigorous description of PLC-beta3 isoenzyme regulation by kinases, lipid binding domains, and non-G protein intermolecular interactions. The kinetics of phosphorylation-mediated inhibition of PLC-beta3 hydrolytic activity will be quantitated in well-controlled in vitro assays. Phospholipid and membrane binding affinities of putative lipid binding domains within the PLC-beta3 molecule will be assessed to further associate structure with function and regulation of PLC- beta activity. Additionally, the association of PLC-beta3 with putative interacting proteins, other than G proteins or kinases, will be identified and the function of these intermolecular interactions quantitated both in vivo and in vitro. These studies, which aim to detail at a molecular level multiple means of regulation of PLC-beta3 activity beyond the well-characterized G protein activation pathway, will contribute to a greater understanding of the basic mechanisms of signal transduction. A detailed, functional map of PLC-beta enzyme regulation may contribute to the design of novel therapeutic agents that intervene selectively into pathophysiological PLC-beta-mediated processes; hormone and neurotransmitter responses associated with PLC-beta activation include, among many others, smooth muscle contraction, platelet aggregation, hormone secretion, smooth muscle hypertrophy and hyperplasia, neuronal activation, and malignant cell proliferation.
|
1 |
2011 |
Filtz, Theresa M |
R15Activity Code Description: Supports small-scale research projects at educational institutions that provide baccalaureate or advanced degrees for a significant number of the Nation’s research scientists but that have not been major recipients of NIH support. The goals of the program are to (1) support meritorious research, (2) expose students to research, and (3) strengthen the research environment of the institution. Awards provide limited Direct Costs, plus applicable F&A costs, for periods not to exceed 36 months. This activity code uses multi-year funding authority; however, OER approval is NOT needed prior to an IC using this activity code. |
Bcl11b Transcription Factor Regulation by Phosphorylation and Sumoylation @ Oregon State University
DESCRIPTION (provided by applicant): Cellular growth, maturation and transformation, among other functions, require the translation of extracellular signals into altered programs of gene expression. The key translators for these signals are transcription factor proteins. Bcl11b is a transcription factor that is critical for the development and function of several organ systems, including the immune and central nervous systems, skin, and craniofacial structures. Importantly, dysregulation of Bcl11b is strongly associated with T-cell acute lymphoblastic leukemia (T-ALL), an aggressive childhood cancer, and acceleration to the lethal blast crisis stage in a mouse model of chronic myelogenous leukemia (CML). The mechanism whereby loss of Bcl11b leads to tumor progression is not understood. In addition, the means by which extracellular signals impinge on transcriptional factors to regulate the transcriptome, in development or neoplastic transformation, is also poorly understood. The long-term goal of this laboratory is to elucidate the mechanisms by which signal transduction pathways regulate transcription factor activities with the goal of altering this regulation for treatment of human diseases. Bcl11b is richly modified by activation of the MAP kinase pathway in thymocytes, and its activity varies from gene repressor to activator dependent upon stimulation. Thus, Bcl11b not only has relevance to human disease, but is an excellent model to study the relationship between sub-molecular structural changes and transcription factor function. The goal of this proposal is to identify the stimulated, post-translation modifications of Bcl11b, and to understand the relationship between varying modified states of Bcl11b and its varied activities. For these studies we will use advanced mass spectrometry techniques, site-directed mutants, over expression and knockdown. Upon successful completion of our specific aims, we will provide a methodological blueprint for others seeking to understand the importance of the temporal organization of amino acid-level modifications of richly decorated transcription factors. Our findings should also highlight potential molecular targets for development of novel therapies in leukemia and perhaps other T cell-associated disorders. We also expect to better understand the regulation of Bcl11b in thymocyte maturation and to apply our findings to other organ systems. Finally, we will train a next generation of students in 21st century biomedical research techniques. PUBLIC HEALTH RELEVANCE: We wish to ultimately understand how to manipulate the gene expression changes leading to T cell cancers and in T cell development. To this end we are studying Bcl11b, an important regulator of gene expression in the immune cells and neurons. Bcl11b is dysregulated in certain T cell leukemia, and mice that lack Bcl11b have an incomplete immune system that lacks mature T cells among other defects. We wish to understand how the activity of Bcl11b is controlled at a molecular level in T cells to begin to understand its control of gene expression.
|
1 |