Identification of cellular deoxyhypusine synthase as a novel target for antiretroviral therapy
J. Clin. Invest. Ilona Hauber, et al. 115:76 doi:10.1172/JCI21949 [Go to this article.]

Figure 1
Inhibition of hypusine formation in eIF-5A by interfering with DHS activity. (A) Schematic representation of the pathway of eIF-5A biosynthesis. Hypusine is required for the biological activity of the protein. The conversion of a specific lysine residue (Lys50) into the unusual amino acid hypusine occurs in 2 posttranslational reactions that are mediated by the enzymes DHS and deoxyhypusine hydroxylase (DHH; see text for details). DHS is a target of experimental low–molecular weight drugs, such as the multivalent guanylhydrazone CNI-1493. (B) CNI-1493 inhibits hypusine formation in eIF-5A in vivo. Jurkat cells were metabolically labeled using either [¹⁴C]putrescine or [³⁵S]cysteine in the presence of either DMSO (solvent control, lane 1) or CNI-1493 (1.0 μM, lane 2; 0.5 μM, lane 3). Equal amounts of the various radiolabeled cellular extracts were then subjected to eIF-5A–specific immunoprecipitation analysis and analyzed by SDS-PAGE and autoradiography. Molecular mass standards are indicated in kDa. (C) Two-dimensional electrophoresis of total proteins from PM1 cells that were metabolically labeled using [¹⁴C]spermidine in the presence of either DMSO (upper panel) or CNI-1493 (1.0 μM; lower panel). Protein separation was performed, using equal amounts of the radiolabeled extracts, by isoelectric focusing in the first dimension on an immobilized linear pH gradient (IPG) from pH 4.0 to 7.0, which was followed by SDS-PAGE separation in the second dimension. Only molecular mass of less than 25.0 kDa is shown in autoradiographs. No radioactive protein spots were detected elsewhere. Molecular mass standards are indicated in kDa on the right.