Interaction of eukaryotic initiation factor 5A with the human immunodeficiency virus type 1 Rev response element RNA and U6 snRNA requires deoxyhypusine or hypusine modification.

Abstract

Hypusine formation on the eukaryotic initiation factor 5A (eIF-5A) precursor represents a unique posttranslational modification that is ubiquitously present in eukaryotic cells and archaebacteria. Specific inhibition of deoxyhypusine synthase leads to growth arrest and cell death. The precise cellular function of eIF-5A and the physiological significance of hypusine modification are not clear. Although the methionyl-puromycin synthesis has been suggested to be the functional assay for eIF-5A activity in vitro, the role of eIF-5A in protein synthesis has not been established. Recent studies have suggested that eIF-5A may be the cellular target of the human immunodeficiency virus type 1 Rev and human T cell leukemia virus type 1 Rex proteins. Motif analysis suggested that eIF-5A resembles a bimodular RNA-binding protein in that it contains a stretch of basic amino acids clustered at the N-terminal region and a leucine-rich stretch at the C-terminal region. Using Rev target RNA, RRE, as a model, we tested the hypothesis that eIF-5A may be an RNA-binding protein. We found that both deoxyhypusine and hypusine-containing eIF-5A can bind to the 252-nt RRE RNA, as determined by a gel mobility shift assay. In contrast, the unmodified eIF-5A precursor cannot. Deoxyhypusine-containing eIF-5A, but not its precursor, could also cause supershift of the Rev stem-loop IIB RRE complex. Preliminary studies also indicated that eIF-5A can bind to RNA such as U6 snRNA and that deoxyhypusine modification appears to be required for the binding. The ability of eIF-5A to directly interact with RNA suggests that deoxyhypusine formation of eIF-5A may be related to its role in RNA processing and protein synthesis. Our study also suggests the possibility of using a gel mobility shift assay for eIF-5A-RNA binding as a functional assay for deoxyhypusine and hypusine formation.

• Authors: Y P Liu, M Nemeroff, Y P Yan, K Y Chen
• Journal: Biological signals (Biol Signals) 1997 May-Jun Vol. 6 Issue 3 Pg. 166-74 ISSN: 1016-0922 [Print] Switzerland
• PMID: 9285100 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Gene Products, rev
• Peptide Initiation Factors
• RNA, Small Nuclear
• RNA, Viral
• RNA-Binding Proteins
• eukaryotic translation initiation factor 5A
• rev Gene Products, Human Immunodeficiency Virus
• hypusine
• deoxyhypusine
• Lysine

Topics

• Gene Products, rev (genetics, metabolism)
• HIV-1 (physiology)
• Humans
• Lysine (analogs & derivatives, metabolism)
• Peptide Initiation Factors (metabolism)
• Protein Binding
• RNA, Small Nuclear (metabolism)
• RNA, Viral (genetics, metabolism)
• RNA-Binding Proteins
• Virus Replication (physiology)
• rev Gene Products, Human Immunodeficiency Virus