Translation initiation factor eIF-5A, the hypusine-containing protein, is phosphorylated on serine and tyrosine and O-glycosylated in Trichomonas vaginalis

• Published in: Microbial pathogenesis Vol. 52; no. 3; pp. 177 - 183
• Main Authors: Carvajal-Gamez, Bertha Isabel, Quintas-Granados, Laura Itzel, Arroyo, Rossana, Mendoza-Hernández, Guillermo, Alvarez-Sánchez, Maria Elizbeth
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2012; Elsevier
• Subjects: antibodies; Biological and medical sciences; biosynthesis; Blotting, Western; concanavalin A; Electrophoresis, Gel, Two-Dimensional; eukaryotic cells; Eukaryotic translation factor (eIF-5A); Eukaryotic Translation Initiation Factor 5A; Fundamental and applied biological sciences. Psychology; genes; Glycosylation; Glycosylations; Isoelectric Point; mass spectrometry; Microbiology; Peptide Initiation Factors - chemistry; Peptide Initiation Factors - metabolism; Phosphorylation; Polyamines; post-translational modification; Post-translational modifications; Protein Processing, Post-Translational; putrescine; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - metabolism; serine; Serine - metabolism; Trichomonas vaginalis; Trichomonas vaginalis - metabolism; tyrosine; Tyrosine - metabolism; Trichomonas vaginalis; Phosphorylation; Post-translational modifications; Polyamines; Glycosylations; Eukaryotic translation factor (eIF-5A); Tyrosine; Protozoa; Initiation factor; Polyamine; Serine; Translation initiation; Glycosylation; Trichomonadida; Genetic translation; Protein; Posttranslational modification; Eukaryotic translation factor (elF-5A); Aminoacid
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2011.12.004

The eukaryotic translation factor eIF-5A is highly conserved throughout eukaryotes and undergoes an unusual polyamine-dependent post-translational modification called hypusination. Trichomonas vaginalis has two tveif-5a genes (tveif-5a1 and tveif-5a2), each encoding a 19-kDa protein. In this report, we describe the detection of two forms with different isoelectric points (5.2 and 5.5) that correspond to the precursor and mature TveIF-5A, respectively. In addition, we demonstrated that only the mature form of TveIF-5A is phosphorylated and glycosylated via two-dimensional gel electrophoresis-western blot (2DE-WB) assays using anti-phosphoserine and anti-phosphotyrosine antibodies and the SNA, ConA and MAA lectins. Interestingly, when the protozoa were grown in 1,4-diamino-2-butanone (DAB), an inhibitor of putrescine biosynthesis, and transferred to medium containing exogenous putrescine, a new spot with an isoelectric point of 5.3 was observed, presumably corresponding to a phosphorylated intermediate or deoxyhypusine form. Our data indicate that, in T. vaginalis, phosphorylations and glycosylations are necessary to obtain the mature TveIF-5A, and we confirm the identity of the precursor, intermediate and mature forms of TveIF-5A by mass spectrometry analysis.
► We reported the post-translation modifications of mature TveIF-5A protein. ► The intermediate form contains a phosphorylation in tyrosine. ► The intermediate form was obtained only in presence of putrescine.