The synthesis of new ribosomes is essential for cell growth, and tightly regulated in response to nutrients and stress. Defects in ribosome synthesis are linked to increased risk of cancer and a variety of congenital defects in rapidly growing tissues such as blood and skin.
The aim of this research is to understand how the RNA and protein components of the ribosome assemble with each other to form the large and small subunits of the ribosome, and to understand how this process is accelerated and regulated by other proteins in the cell. Time-resolved footprinting can visualize changes in the RNA and protein interactions within 10-20 milliseconds, resulting in detailed information about the folding pathway of the RNA and RNA-protein recognition. This method will be used to investigate slow remodeling of RNA-protein complexes in the head of the 30S subunit, and study how maturation factors increase the rate of protein binding and assembly. A synchrotron X-ray beam will be used to footprint 30S assembly intermediates in living bacteria. The dynamics of a conformational switch in the rRNA will be observed directly using fluorescence spectroscopy of single RNA-protein complexes. The results of this research will increase understanding of how large RNA-protein complexes are necessary for cell growth, and contribute to a molecular explanation of human disorders arising from defects in the assembly of these complexes.

Public Health Relevance

Ribosomes are a cellular complex that synthesizes new proteins, and cells must produce thousands of new ribosomes each minute to grow and divide. Deficiencies in ribosome production cause diseases of the blood, skin and other tissues, and have been linked to cancer. This research will visualize how the RNA and protein components of the ribosome come together, to learn how this process goes awry and how such defects may be corrected.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM060819-15
Application #
8626407
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Preusch, Peter C
Project Start
1999-05-01
Project End
2016-02-28
Budget Start
2014-03-01
Budget End
2015-02-28
Support Year
15
Fiscal Year
2014
Total Cost
$329,663
Indirect Cost
$120,083
Name
Johns Hopkins University
Department
Physiology
Type
Schools of Arts and Sciences
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Sharma, Indra Mani; Korman, Arthur; Woodson, Sarah A (2018) The Hfq chaperone helps the ribosome mature. EMBO J 37:
Sharma, Indra Mani; Rappé, Mollie C; Addepalli, Balasubrahmanyam et al. (2018) A metastable rRNA junction essential for bacterial 30S biogenesis. Nucleic Acids Res 46:5182-5194
Hao, Yumeng; Bohon, Jen; Hulscher, Ryan et al. (2018) Time-Resolved Hydroxyl Radical Footprinting of RNA with X-Rays. Curr Protoc Nucleic Acid Chem 73:e52
Abeysirigunawardena, Sanjaya C; Kim, Hajin; Lai, Jonathan et al. (2017) Evolution of protein-coupled RNA dynamics during hierarchical assembly of ribosomal complexes. Nat Commun 8:492
Hulscher, Ryan M; Bohon, Jen; Rappé, Mollie C et al. (2016) Probing the structure of ribosome assembly intermediates in vivo using DMS and hydroxyl radical footprinting. Methods 103:49-56
Lee, Hui-Ting; Kilburn, Duncan; Behrouzi, Reza et al. (2015) Molecular crowding overcomes the destabilizing effects of mutations in a bacterial ribozyme. Nucleic Acids Res 43:1170-6
Abeysirigunawardena, Sanjaya C; Woodson, Sarah A (2015) Differential effects of ribosomal proteins and Mg2+ ions on a conformational switch during 30S ribosome 5'-domain assembly. RNA 21:1859-65
Kim, Hajin; Abeysirigunawarden, Sanjaya C; Chen, Ke et al. (2014) Protein-guided RNA dynamics during early ribosome assembly. Nature 506:334-8
Desai, Ravi; Kilburn, Duncan; Lee, Hui-Ting et al. (2014) Increased ribozyme activity in crowded solutions. J Biol Chem 289:2972-7
Hua, Boyang; Han, Kyu Young; Zhou, Ruobo et al. (2014) An improved surface passivation method for single-molecule studies. Nat Methods 11:1233-6

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