The stability and translation of many mRNAs encoding oncoproteins and cytokines are regulated by AU-rich elements (AREs), a diverse but evolutionarily conserved family of RNA sequences localized to their 3'untranslated regions. Disruption of ARE-directed regulatory mechanisms can contribute to oncogenesis and severe inflammatory syndromes. Our long-term objectives are to determine how the size and sequence diversity of AREs directs post-transcriptional regulation at the gene-specific level, and how gene-specific characteristics of AREs might ultimately be exploited as targets for novel therapies to treat some cancers and chronic inflammatory diseases. Our central hypothesis is that the metabolic fate of any ARE-containing mRNA is directed by the population of cellular trans-factors targeting each transcript;however, the biochemical basis for selecting one factor over another remains poorly defined. Recent findings indicate that some ARE-binding factors target distinct but overlapping mRNA subpopulations, and that local RNA secondary structure can influence trans-factor selectivity. Also, some factors can remodel local RNA structure or form oligomeric complexes on AREs. This project uses a series of biochemical and molecular biological strategies to define the roles of specific molecular determinants in the formation of stable, functional ribonucleoprotein (RNP) complexes on AREs. Using the ubiquitously expressed ARE-binding proteins AUF1 and HuR as model systems, we will first characterize specific protein subdomains contributing to ARE binding affinity and RNA-dependent protein oligomerization, and test the functional significance of these domains in cells (Aim 1). Second, we will identify specific and non-specific RNA primary structural requirements for protein binding, and assess the use of these sequences among the cellular mRNA subpopulation(s) interacting with these factors (Aim 2). Finally, we will determine how local RNA structure directs the recruitment and positioning of AUF1 and HuR on ARE substrates and influences the cellular consequences of these interactions (Aim 3). We anticipate that our approach will permit the mechanics of protein selectivity and binding to be evaluated in much greater detail than previously reported, largely through the use of steady-state and time-resolved fluorescence-based assay systems that we have adapted to study RNA-protein binding equilibria and RNA conformational events. Together, these studies will further our understanding of the relationships between ARE structure, trans-factor recognition, and the cellular functions of resulting RNP complexes.

Public Health Relevance

Cancer and other serious clinical syndromes result when the expression of proteins regulating cell proliferation and differentiation becomes uncontrolled. Cells use many mechanisms to limit the production of these proteins, including rapid destruction or silencing of the messenger RNAs (mRNAs) encoding them through a family of RNA sequences called AU-rich elements (AREs). The proposed studies will determine how different cellular factors recognize unique ARE sequences and target their associated mRNAs for destruction, opening the possibility that these gene-specific interactions might be exploited as targets for novel therapies to treat some cancers and chronic inflammatory diseases.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA102428-09
Application #
8248659
Study Section
Molecular Genetics C Study Section (MGC)
Program Officer
Knowlton, John R
Project Start
2003-07-01
Project End
2014-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
9
Fiscal Year
2012
Total Cost
$257,996
Indirect Cost
$85,999
Name
University of Maryland Baltimore
Department
Biochemistry
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
White, Elizabeth J F; Matsangos, Aerielle E; Wilson, Gerald M (2016) AUF1 regulation of coding and noncoding RNA. Wiley Interdiscip Rev RNA :
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Hwang, Bor-Jang; Jin, Jin; Gunther, Randall et al. (2015) Association of the Rad9-Rad1-Hus1 checkpoint clamp with MYH DNA glycosylase and DNA. DNA Repair (Amst) 31:80-90
Wells, Melissa L; Washington, Onica L; Hicks, Stephanie N et al. (2015) Post-transcriptional regulation of transcript abundance by a conserved member of the tristetraprolin family in Candida albicans. Mol Microbiol 95:1036-53
Temburnikar, Kartik W; Ross, Christina R; Wilson, Gerald M et al. (2015) Antiproliferative activities of halogenated pyrrolo[3,2-d]pyrimidines. Bioorg Med Chem 23:4354-63
White, Michael R; Khan, Mohd M; Deredge, Daniel et al. (2015) A dimer interface mutation in glyceraldehyde-3-phosphate dehydrogenase regulates its binding to AU-rich RNA. J Biol Chem 290:1770-85
Ross, Christina R; Temburnikar, Kartik W; Wilson, Gerald M et al. (2015) Mitotic arrest of breast cancer MDA-MB-231 cells by a halogenated thieno[3,2-d]pyrimidine. Bioorg Med Chem Lett 25:1715-7
Xu, Li; Ning, Huan; Gu, Ling et al. (2015) Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway. Oncotarget 6:41679-91
White, Michael R; Khan, Mohd M; Deredge, Daniel et al. (2015) A dimer interface mutation in glyceraldehyde 3-phosphate dehydrogenase regulates its binding to AU-rich RNA. J Biol Chem 290:4129
Yoon, Je-Hyun; Jo, Myung Hyun; White, Elizabeth J F et al. (2015) AUF1 promotes let-7b loading on Argonaute 2. Genes Dev 29:1599-604

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