Glutathione is required for growth and prespore cell differentiation in Dictyostelium.
Glutathione (GSH) is the most abundant non-protein thiol in eukaryotic cells and acts as reducing equivalent in many cellular processes. We investigated the role of glutathione in Dictyostelium development by disruption of gamma-glutamylcysteine synthetase (GCS), an essential enzyme in glutathione biosynthesis. GCS-null strain showed glutathione auxotrophy and could not grow in medium containing other thiol compounds. The developmental progress of GCS-null strain was determined by GSH concentration contained in preincubated media before development. GCS-null strain preincubated with 0.2 mM GSH was arrested at mound stage or formed bent stalk-like structure during development. GCS-null strain preincubated with more than 0.5 mM GSH formed fruiting body with spores, but spore viability was significantly reduced. In GCS-null strain precultured with 0.2 mM GSH, prestalk-specific gene expression was delayed, while prespore-specific gene and spore-specific gene expressions were not detected. In addition, GCS-null strain precultured with 0.2 mM GSH showed prestalk tendency and extended G1 phase of cell cycle. Since G1 phase cells at starvation differentiate into prestalk cells, developmental defect of GCS-null strain precultured with 0.2 mM GSH may result from altered cell cycle. These results suggest that glutathione itself is essential for growth and differentiation to prespore in Dictyostelium.
Laboratory of Biophysics, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea.
Beom-Jun
BJ
Kim
Chang-Hoon
CH
Choi
Chang-Hun
CH
Lee
Sun-Young
SY
Jeong
Ji-Sun
JS
Kim
Bo-Yeon
BY
Kim
Hyung-Soon
HS
Yim
Sa-Ouk
SO
Kang
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002453:Cell Cycle; D002454:Cell Differentiation; D002678:Chimera / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D016384:Consensus Sequence; D003470:Culture Media / Q000737:chemistry; D016054:DNA, Protozoan / Q000032:analysis; D004023:Dictyostelium / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D005434:Flow Cytometry; D018507:Gene Expression Regulation, Developmental; D017125:Genes, Protozoan; D005721:Glutamate-Cysteine Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005978:Glutathione / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009154:Mutation; D017386:Sequence Homology, Amino Acid; D033761:Spores, Protozoan / Q000166:cytology / Q000235:genetics / Q000502:physiology*
D003470:Culture Media; D016054:DNA, Protozoan; D049452:Green Fluorescent Proteins; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione