High impact information on HYP2

• Expression of the TIF51A gene (encoding eIF-5A) complemented the temperature-sensitive growth and mRNA decay phenotypes of ts1159 [1].
• Disruption of the DCS1 gene manifests a threefold increase of the TIF51A mRNA half-life [2].
• Northern (RNA) blot analysis shows two mRNA species, a larger mRNA (0.9 kb) transcribed from TIF51A and a smaller mRNA (0.8 kb) encoded by TIF51B [3].
• The TIF51A gene was altered by site-directed mutagenesis at the site of hypusination by changing the Lys codon to that for Arg, thereby producing a stable protein that retains the positive charge but is not modified to the hypusine derivative [3].
• However, strains with both TIF51A and TIF51B disrupted are not viable, indicating that eIF-5a is essential for cell growth in yeast cells [3].

Biological context of HYP2

• The hypusine-containing protein Hyp2p, encoded by the HYP2 gene in yeast, is present under both aerobic and anaerobic conditions, whereas Hyp1p synthesis is restricted to anaerobiosis. hyp1 disruption mutants grown under anaerobic conditions reveal no detectable alteration in phenotype relative to wild-type strains [4].
• The HYP1-gene is identical to the ANB1-gene and has already been localized on chromosome X. However, the chromosomal localization of the HYP2-gene has not been elucidated [5].

Associations of HYP2 with chemical compounds

• Moreover, Hypp from various eukaryotic species (slime mold, alfalfa and man) carries the lysine to hypusine modification when expressed in yeast and can substitute functionally for Hyp2p in strains disrupted for HYP2, indicating a highly conserved function of this protein [4].
• We physically mapped TIF51A and its associated serine tRNA2 gene by the method of chromosome fragmentation and pulsed-field gel electrophoresis [6].
• In order to study the products of the two genes individually, yeast strains were constructed that express either TIF51A or TIF51B under control of a galactose promoter [7].

Regulatory relationships of HYP2

• Under the aerobic growth conditions of this study, the 0.8-kb TIF51B transcript is not detected in the wild-type strain and is expressed only when TIF51A is disrupted [3].

Other interactions of HYP2

• In Saccharomyces cerevisiae, hypusine-containing proteins are encoded by two closely related genes, HYP1 and HYP2, which are regulated reciprocally by oxygen and heme [8].

Analytical, diagnostic and therapeutic context of HYP2

• Chromosomal localization of the HYP2-gene in Saccharomyces cerevisiae and use of pulsed-field gel electrophoresis for detection of irregular recombination events in gene disruption experiments [5].
• Here an example is shown where overexpression of the yeast HYP2 genes, coding for a hypusine-containing protein, was alternatively analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) alone or by two-dimensional (2-D) gel electrophoresis, using the narrowed pH range of 4.5-5 [9].

References