Protein synthesis plays a central role in growth and differentiation, response to change, and overall energy utilization of the cell. Viruses utilize the host translational machinery, and host cells have evolved complex antiviral responses. Deregulation of protein synthesis leads to malignant transformation. This project seeks to understand the rate- limiting step of protein synthesis, recruitment of mRNA to the ribosome, where much of translational control occurs. Two key factors in this process are eIF4E, the mRNA cap-binding protein, and eIF4G, a protein which links together the 40S ribosome, eIF4E, and the RNA helicase eIF4A. The roles of the eIF4 initiation factors will be studied by asking the following questions: 1. How do the eIF4 factors participate in recruitment of mRNA to the ribosome? We will arrest of intermediates of initiation complex assembly using allyloligonucleotides, overexpress eIF4G and a protease- resistant variant in cultured cells to determine oncogenic phenotype, test the effect of specific functional domains of eIF4G, and characterize eIF4E from C. elegans with respect to binding to m7G- and m3(2,2,7) G-containing caps. How does the phosphorylation of eIF4E affect protein synthesis? We will express in CREF cells eIF4E variants around the phosphorylation site to determine phenotype, examine the characteristics of eIF4E phosphorylation by PKCzeta, determine the properties of phosphorylated eIF4E by biophysical methods, and test whether eIF4E participates in a phosphorylation cycle during initiation. What physiological factors determine the intracellular levels and activity of eIF4G? We will study eIF4G synthesis, degradation and steady-state levels as a function several parameters as well as temperature-dependent conformational changes in recombinant eIF4G by biophysical and biochemical. How does the IRES of eIF4G mRNA direct internal initiation? We will delineate the borders of the eIF4G IRES, determine its secondary structure, characterize its translation in vivo, and attempt to find conditions for its utilization in vitro. And finally, what is the structure of the eIF4E gene? We will complete determination of the gene structure, define the promoter, and attempt to identify cis-acting regulatory elements.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Physiological Chemistry Study Section (PC)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Louisiana State University Hsc Shreveport
Schools of Medicine
United States
Zip Code
Ziemniak, Marcin; Mugridge, Jeffrey S; Kowalska, Joanna et al. (2016) Two-headed tetraphosphate cap analogs are inhibitors of the Dcp1/2 RNA decapping complex. RNA 22:518-29
Korneeva, Nadejda L; Song, Anren; Gram, Hermann et al. (2016) Inhibition of Mitogen-activated Protein Kinase (MAPK)-interacting Kinase (MNK) Preferentially Affects Translation of mRNAs Containing Both a 5'-Terminal Cap and Hairpin. J Biol Chem 291:3455-67
Fan, Ruping; Schrott, Lisa M; Snelling, Stephen et al. (2015) Chronic oxycodone induces integrated stress response in rat brain. BMC Neurosci 16:58
Kowalska, Joanna; Wypijewska del Nogal, Anna; Darzynkiewicz, Zbigniew M et al. (2014) Synthesis, properties, and biological activity of boranophosphate analogs of the mRNA cap: versatile tools for manipulation of therapeutically relevant cap-dependent processes. Nucleic Acids Res 42:10245-64
Grudzien-Nogalska, Ewa; Reed, Brent C; Rhoads, Robert E (2014) CPEB1 promotes differentiation and suppresses EMT in mammary epithelial cells. J Cell Sci 127:2326-38
Ziemniak, Marcin; Szabelski, Mariusz; Lukaszewicz, Maciej et al. (2013) Synthesis and evaluation of fluorescent cap analogues for mRNA labelling. RSC Adv 3:
Su, Wei; Slepenkov, Sergey V; Slevin, Michael K et al. (2013) mRNAs containing the histone 3' stem-loop are degraded primarily by decapping mediated by oligouridylation of the 3' end. RNA 19:1-16
Su, Wei; Slepenkov, Sergey; Grudzien-Nogalska, Ewa et al. (2011) Translation, stability, and resistance to decapping of mRNAs containing caps substituted in the triphosphate chain with BH3, Se, and NH. RNA 17:978-88
Chiluiza, David; Bargo, Sharon; Callahan, Robert et al. (2011) Expression of truncated eukaryotic initiation factor 3e (eIF3e) resulting from integration of mouse mammary tumor virus (MMTV) causes a shift from cap-dependent to cap-independent translation. J Biol Chem 286:31288-96
Senkovich, Olga A; Yin, Jun; Ekshyyan, Viktoriya et al. (2011) Helicobacter pylori AlpA and AlpB bind host laminin and influence gastric inflammation in gerbils. Infect Immun 79:3106-16

Showing the most recent 10 out of 30 publications