Pro-Apoptotic Role of the HumanYPEL5Gene Identified by Functional Complementation of a Yeastmoh1Δ Mutation.
To examine the pro-apoptotic role of the human ortholog (YPEL5) of theDrosophilaYippee protein, the cell viability ofSaccharomyces cerevisiaemutant strain with deletedMOH1, the yeast ortholog, was compared with that of the wild-type (WT)-MOH1strain after exposure to different apoptogenic stimulants, including UV irradiation, methyl methanesulfonate (MMS), camptothecin (CPT), heat shock, and hyperosmotic shock. Themoh1Δ mutant exhibited enhanced cell viability compared with the WT-MOH1strain when treated with lethal UV irradiation, 1.8 mM MMS, 100 µ CPT, heat shock at 50°C, or 1.2 M KCl. At the same time, the level of Moh1 protein was commonly up-regulated in the WT-MOH1strain as was that of Ynk1 protein, which is known as a marker for DNA damage. Although the enhanced UV resistance of themoh1Δ mutant largely disappeared following transformation with the yeastMOH1gene or one of the humanYPEL1-YPEL5genes, the transformant bearing pYES2-YPEL5was more sensitive to lethal UV irradiation and its UV sensitivity was similar to that of the WT-MOH1strain. Under these conditions, the UV irradiation-induced apoptotic events, such as FITC-Annexin V stainability, mitochondrial membrane potential (ΔΨm) loss, and metacaspase activation, occurred to a much lesser extent in themoh1Δ mutant compared with the WT-MOH1strain and the mutant strain bearing pYES2-MOH1or pYES2-YPEL5. These results demonstrate the functional conservation between yeast Moh1 and human YPEL5, and their involvement in mitochondria-dependent apoptosis induced by DNA damage.
Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Ji Young
JY
Lee
Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Do Youn
DY
Jun
Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Ju Eun
JE
Park
Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Gi Hyun
GH
Kwon
Department of Biological Sciences, Andong National University, Andong 36729, Republic of Korea.
Jong-Sik
JS
Kim
Laboratory of Immunobiology, School of Life Science and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566, Republic of Korea.
Young Ho
YH
Kim
D000595:Amino Acid Sequence; D017209:Apoptosis / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005816:Genetic Complementation Test; D006801:Humans; D005810:Multigene Family; D009154:Mutation; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015003:Yeasts / Q000235:genetics* / Q000378:metabolism
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C553177:YPEL5 protein, human
Apoptosis; DNA damage; Drosophila Yippee; S. cerevisiae MOH1; human YPEL5; metacaspase