Eukaryotic translation initiation is a complex and highly regulated process by which the ribosome is initiated in protein synthesis. This process engages a large number of factors that organize subunit dissociation, recruitment of the small ribosomal subunit to the mRNA, placement of the Met-tRNAi into the P- site, scanning of the 5'UTR, start-codon selection, and subunit joining. The efficiency of translation affects the concentrations of synthesized proteins, which is crucial for processes, such as progress through cell cycle, onset of apoptosis, progress of development, or cell transformation. Translation initiation is modulated by properties of the mRNA, such as elements located in the untranslated regions, binding of regulatory proteins, signaling events, or environmental factors. Mechanisms of eukaryotic translation initiation are only partially understood at a molecular level. Our previous research has made important contributions to this field including structure determinations of the cap-binding protein elF4E, its complex with elF4G, discovery of inhibitors of the elF4E/elF4G interaction, structures of elF1A and elF1and identification of their locations on the 40S ribosomal particle, the structure determination of elF2a and discovery of the mechanism of its interaction with e!F2y and Met-tRNAi. Here we propose to continue this successful research pursuing three specific aims:
Aim 1 : Unveil mechanisms of mRNA recruitment to the 40S ribosomal particle through cap-binding proteins.
Aim 2 : Elucidate mechanisms of initiation complex assembly and start-codon selection through studies of the interactions of the initiation factors elF1, elF1A, elF5, elFSB and elF2.
Aim 3 : Characterize the role of the ATP-dependent RNA helicase elF4A in translation initiation.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA068262-15
Application #
7758804
Study Section
Macromolecular Structure and Function C Study Section (MSFC)
Program Officer
Knowlton, John R
Project Start
1996-05-08
Project End
2011-01-31
Budget Start
2010-02-01
Budget End
2011-01-31
Support Year
15
Fiscal Year
2010
Total Cost
$215,140
Indirect Cost
Name
Harvard University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
Obayashi, Eiji; Luna, Rafael E; Nagata, Takashi et al. (2017) Molecular Landscape of the Ribosome Pre-initiation Complex during mRNA Scanning: Structural Role for eIF3c and Its Control by eIF5. Cell Rep 18:2651-2663
Salvi, Nicola; Papadopoulos, Evangelos; Blackledge, Martin et al. (2016) The Role of Dynamics and Allostery in the Inhibition of the eIF4E/eIF4G Translation Initiation Factor Complex. Angew Chem Int Ed Engl 55:7176-9
Edmonds, Katherine A; Wagner, Gerhard (2015) (1)H, (13)C, and (15)N backbone and sidechain chemical shift assignments for the HEAT2 domain of human eIF4GI. Biomol NMR Assign 9:157-60
Sekiyama, Naotaka; Arthanari, Haribabu; Papadopoulos, Evangelos et al. (2015) Molecular mechanism of the dual activity of 4EGI-1: Dissociating eIF4G from eIF4E but stabilizing the binding of unphosphorylated 4E-BP1. Proc Natl Acad Sci U S A 112:E4036-45
Yi, Tingfang; Arthanari, Haribabu; Akabayov, Barak et al. (2015) eIF1A augments Ago2-mediated Dicer-independent miRNA biogenesis and RNA interference. Nat Commun 6:7194
Leigh, Kendra E; Sharma, Mayuri; Mansueto, My Sam et al. (2015) Structure of a herpesvirus nuclear egress complex subunit reveals an interaction groove that is essential for viral replication. Proc Natl Acad Sci U S A 112:9010-5
Yi, Tingfang; Kabha, Eihab; Papadopoulos, Evangelos et al. (2014) 4EGI-1 targets breast cancer stem cells by selective inhibition of translation that persists in CSC maintenance, proliferation and metastasis. Oncotarget 5:6028-37
Mahalingam, Poornachandran; Takrouri, Khuloud; Chen, Ting et al. (2014) Synthesis of rigidified eIF4E/eIF4G inhibitor-1 (4EGI-1) mimetic and their in vitro characterization as inhibitors of protein-protein interaction. J Med Chem 57:5094-111
Yefidoff-Freedman, Revital; Chen, Ting; Sahoo, Rupam et al. (2014) 3-substituted indazoles as configurationally locked 4EGI-1 mimetics and inhibitors of the eIF4E/eIF4G interaction. Chembiochem 15:595-611
Luna, Rafael E; Akabayov, Sabine R; Ziarek, Joshua J et al. (2014) Examining weak protein-protein interactions in start codon recognition via NMR spectroscopy. FEBS J 281:1965-73

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