Abstract

Research in this laboratory is directed at understanding the cellular mechanisms responsible for induced differentiation of Friend murine erythroleukemia (MEL) cells. Recent results demonstrate that: 1) transformation of these erythroblasts directly affects translation initiation; and 2) exposure to inducers of differentiation rapidly decreases translation rate and this decrease precedes differentiation. This and other abundant evidence indicate that translation is a significant regulator of gene expression in transformed cells. The experiments outlined in this proposal will determine the role of translational regulation of gene expression in transformation and differentiation of MEL cells. Inducers are shown to affect a previously undescribed site for translational regulation where MRNA accumulates as monosomes and only slowly progresses to translating polysomes. The accumulation of monosomes appears to be due to """"""""stalling"""""""" at the initiating AUG codon of MRNA. The experiments outlined in this proposal will determine the precise step in translation affected by inducers by """"""""footprinting"""""""" the interaction of ribosomes and MRNA and analyzing the tRNAs and peptides present in the stalled monosome. Factors which regulate stalling will be analyzed by developing an in vitro assay for this event and by purification and further characterization of two ribosomal proteins which are specifically absent from these stalled monosomes. Translation initiation rate will be selectively increased or decreased in MEL cells utilizing a recently described genetic approach. This will determine the role of translation initiation in transforming these cells and in their induced differentiation. The results of these experiments will provide insight into eukaryotic growth regulation and translations) regulatory mechanisms.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK043414-02
Application #
3244820
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1992-05-01
Project End
1996-04-30
Budget Start
1993-05-01
Budget End
1994-04-30
Support Year
2
Fiscal Year
1993
Total Cost
Indirect Cost

  Institution

Name
Case Western Reserve University
Department
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106

  Publications

Komar, Anton A; Gross, Stephane R; Barth-Baus, Diane et al. (2005) Novel characteristics of the biological properties of the yeast Saccharomyces cerevisiae eukaryotic initiation factor 2A. J Biol Chem 280:15601-11
Constantinou, Constantina; Bushell, Martin; Jeffrey, Ian W et al. (2003) p53-induced inhibition of protein synthesis is independent of apoptosis. Eur J Biochem 270:3122-32
Horton, Lynn E; Bushell, Martin; Barth-Baus, Diane et al. (2002) p53 activation results in rapid dephosphorylation of the eIF4E-binding protein 4E-BP1, inhibition of ribosomal protein S6 kinase and inhibition of translation initiation. Oncogene 21:5325-34
Gelperin, Daniel; Horton, Lynn; DeChant, Anne et al. (2002) Loss of ypk1 function causes rapamycin sensitivity, inhibition of translation initiation and synthetic lethality in 14-3-3-deficient yeast. Genetics 161:1453-64
Zoll, Wendy L; Horton, Lynn E; Komar, Anton A et al. (2002) Characterization of mammalian eIF2A and identification of the yeast homolog. J Biol Chem 277:37079-87
Barth-Baus, Diane; Stratton, Carl A; Parrott, Lou et al. (2002) S6 phosphorylation-independent pathways regulate translation of 5'-terminal oligopyrimidine tract-containing mRNAs in differentiating hematopoietic cells. Nucleic Acids Res 30:1919-28
Gelperin, D; Horton, L; Beckman, J et al. (2001) Bms1p, a novel GTP-binding protein, and the related Tsr1p are required for distinct steps of 40S ribosome biogenesis in yeast. RNA 7:1268-83
Kroll, S L; Barth-Baus, D; Hensold, J O (2001) The carboxyl-terminal domain of the granulocyte colony-stimulating factor receptor uncouples ribosomal biogenesis from cell cycle progression in differentiating 32D myeloid cells. J Biol Chem 276:49410-8
Richter, N J; Rogers Jr, G W; Hensold, J O et al. (1999) Further biochemical and kinetic characterization of human eukaryotic initiation factor 4H. J Biol Chem 274:35415-24
Richter-Cook, N J; Dever, T E; Hensold, J O et al. (1998) Purification and characterization of a new eukaryotic protein translation factor. Eukaryotic initiation factor 4H. J Biol Chem 273:7579-87

Showing the most recent 10 out of 14 publications