Abstract

This research will study the molecular mechanism of peptide chain initiation in animal cells and the roles of different factors in regulation of protein synthesis under different physiological conditions, which include mitogen stimulation and viral infection. The first step in peptide chain initiation is the formation of a ternary complex between the eukaryotic peptide chain initiation factor 2 (eIF-2), Met-tRNAf and GTP,MET-tRNA.f eIF-2-GTP. The next step is the transfer of Met-tRNAf. 40S mRNA complex. An important regulatory mechanism involves one or more eIF-2 kinases and an eIF-2 kinase inhibitor (a 67 kDa polypeptide - p67). eIF-2 kinases phosphorylate eIF-2 and thus inhibit protein synthesis and the increased availability of p67 renders eIF-2 resistant to eIF-2 kinase phosphorylation and so promotes protein synthesis in the presence of eIF-2 kinases. Objectives of the research are: (1) Studies of the characteristics and factor requirements for ternary and Met-tRNAf. 40S mRNA complex formation. Endeavors will be made to extensively purify different protein factors and analyze their roles and requirements in ternary and Met-tRNAf. 40smRNA complex formation. Also, Drs. Hershey and Merrick agreed to supply peptide chain initiation factors purified in their laboratories. The investigators will also compare the factor preparation from all three laboratories (Gupta, Hershey, Merrick) and arrive at a mutually agreeable definition regarding the characteristics and requirements for these factors in ternary and Met-tRNAf. 40S mRNA complex formation. (2) Studies of the regulation of protein synthesis initiation. Emphasis will be given to the studies of the roles of p67 and eIF-2 kinases in the regulatory process. Efforts will be made to determine qualitative and quantitative changes in p67, eIF-2 kinases and other factor activities during mitogen stimulation, as well as during polio viral infection. These changes will then be related to the protein synthesis activities of the cells.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM022079-16
Application #
3270902
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1978-05-01
Project End
1995-06-30
Budget Start
1992-07-01
Budget End
1993-06-30
Support Year
16
Fiscal Year
1992
Total Cost
Indirect Cost

  Institution

Name
University of Nebraska Lincoln
Department
Type
Schools of Arts and Sciences
DUNS #
555456995
City
Lincoln
State
NE
Country
United States
Zip Code
68588

  Publications

Datta, B; Datta, R (1999) Induction of apoptosis due to lowering the level of eukaryotic initiation factor 2-associated protein, p67, from mammalian cells by antisense approach. Exp Cell Res 246:376-83
Datta, B; Datta, R; Mukherjee, S et al. (1999) Increased phosphorylation of eukaryotic initiation factor 2alpha at the G2/M boundary in human osteosarcoma cells correlates with deglycosylation of p67 and a decreased rate of protein synthesis. Exp Cell Res 250:223-30
Chatterjee, M; Chatterjee, N; Datta, R et al. (1998) Expression and activity of p67 are induced during heat shock. Biochem Biophys Res Commun 249:113-7
Zou, C; Zhang, Z; Wu, S et al. (1998) Molecular cloning and characterization of a rabbit eIF2C protein. Gene 211:187-94
Saha, D; Wu, S; Bose, A et al. (1997) Viral infection. II. Hemin induces overexpression of p67 as it partially prevents appearance of an active p67-deglycosylase in baculovirus-infected insect cells. Arch Biochem Biophys 342:373-82
Gupta, S; Wu, S; Chatterjee, N et al. (1995) Regulation of an eukaryotic initiation factor-2 (eIF-2) associated 67 kDa glycoprotein (p67) and its requirement in protein synthesis. Gene Expr 5:113-22
Chakraborty, A; Saha, D; Bose, A et al. (1994) Mechanism of action of an eukaryotic initiation factor-2 (eIF-2) associated 67 kDa glycoprotein (p67) and an eIF-2 kinase (dsI). Indian J Biochem Biophys 31:236-42
Parkhurst, K M; Hileman, R E; Saha, D et al. (1994) Thermodynamic characterization of the cooperativity of 40S complex formation during the initiation of eukaryotic protein synthesis. Biochemistry 33:15168-77
Chakraborty, A; Saha, D; Bose, A et al. (1994) Regulation of eIF-2 alpha-subunit phosphorylation in reticulocyte lysate. Biochemistry 33:6700-6
Hileman, R E; Parkhurst, K M; Gupta, N K et al. (1994) Synthesis and characterization of conjugates formed between periodate-oxidized ribonucleotides and amine-containing fluorophores. Bioconjug Chem 5:436-44

Showing the most recent 10 out of 24 publications