The N-terminal region of eukaryotic translation initiation factor 5A signals to nuclear localization of the protein.
The eukaryotic translation initiation factor 5A (eIF5A) is a ubiquitous protein of eukaryotic and archaeal organisms which undergoes hypusination, a unique post-translational modification. We have generated a polyclonal antibody against murine eIF5A, which in immunocytochemical assays in B16-F10 cells revealed that the endogenous protein is preferentially localized to the nuclear region. We therefore analyzed possible structural features present in eIF5A proteins that could be responsible for that characteristic. Multiple sequence alignment analysis of eIF5A proteins from different eukaryotic and archaeal organisms showed that the former sequences have an extended N-terminal segment. We have then performed in silico prediction analyses and constructed different truncated forms of murine eIF5A to verify any possible role that the N-terminal extension might have in determining the subcellular localization of the eIF5A in eukaryotic organisms. Our results indicate that the N-terminal extension of the eukaryotic eIF5A contributes in signaling this protein to nuclear localization, despite of bearing no structural similarity with classical nuclear localization signals.
Parreiras-E-Silva
Lucas T
LT
Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil.
Gomes
Marcelo D
MD
Oliveira
Eduardo B
EB
Costa-Neto
Claudio M
CM
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009154:Mutation; D019913:Nuclear Localization Signals / Q000235:genetics / Q000502:physiology*; D010448:Peptide Initiation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014162:Transfection; D000097574:Eukaryotic Translation Initiation Factor 5A
D049452:Green Fluorescent Proteins; D019913:Nuclear Localization Signals; D010448:Peptide Initiation Factors; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D000097574:Eukaryotic Translation Initiation Factor 5A