Tributyltin induces Yca1p-dependent cell death of yeast Saccharomyces cerevisiae

Abstract

-Tributyltin chloride (TBT), an environmental pollutant, is toxic to a variety of eukaryotic and prokaryotic organisms. Although it has been reported that TBT induces apoptotic cell death in mammalian, the action of TBT on eukaryotic microorganisms has not yet been fully investigated. In this study we examined the mechanism involved in cell death caused by TBT exposure in Saccharomyces cerevisiae. The median lethal concentration of TBT was 10 μM for the parent strain BY4741 and 3 μM for the pdr5 -tions revealed nuclear condensation and chromatin fragmentation in cells treated with TBT indicating that cells underwent an apoptosis-like cell dearth. TBT-induced cell death was suppressed by deletion of the yca1 gene encoding a homologue of the mammalian caspase. In parallel, reactive oxygen species (ROS) were produced by TBT. These results suggest that TBT induces apoptosis-like cell death in yeast via an induced apoptotic cell death in yeast.

Bfr1p is responsible for tributyltin resistance in Schizosaccharomyces pombe

“…Even in the presence or absence of functional Bfr1p, TBT at the low concentration decreased the growth rate but did not induce cell death of S. pombe, while at the high concentration (more than ten micromolar) it induced cell death. These results are in parallel with the concentration-dependent action of TBT in cell cycle and cell death previously observed in S. cerevisiae (Chahomchuen et al, 2009).…”

“…We have found that TBT induced apoptosis in S. cerevisiae, which was Yca1p-dependent and likely mediated by production of reactive oxygen species (Chahomchuen et al, 2009). Whether a decrease in the cell viability of S. pombe by TBT at high concentrations (Fig.…”

“…The LC 50 value of TBT was estimated to be 10 μM for the parent strain and 3 μM for the mutant of S. cerevisiae (Chahomchuen et al, 2009). The identity and similarity of the amino acid sequences of S. pombe Bfr1p with those of S. cerevisiae Pdr5p were 40.8% and 80.1%, respectively.…”

“…Studies on the marine yeast such as Debaryomyces hansenii (Laurence et al, 1989), Rhodotorula ferulica (Veiga et al, 1997), Saccharomyces cerevisiae (Golin et al, 2000;Masia et al, 1998) or Candida maltosa (White and Tobin, 2004) indicated that TBT induced cellular K + leakage as well as a defect in ATP production. Recently we found that TBT induced apoptosis of S. cerevisiae via production of reactive oxygen species and caspase-like Yca1p-dependent pathway (Chahomchuen et al, 2009). Interestingly, at low concentration, this compound did not induce cell death but arrested the cell growth of S. cerevisiae, suggesting a concentration-dependent action of TBT in cell cycle and cell death.…”

The Arabidopsis METACASPASE9 Degradome

“…The yeast metacaspase, termed Yeast Caspase1 (YCA1), is required for various stress-induced cell death events, including oxidative, osmotic, toxic, and virus-induced stresses and aging (Madeo et al, 2002;Herker et al, 2004;Ivanovska and Hardwick, 2005;Chahomchuen et al, 2009). YCA1 is also involved in cell cycle regulation (Lee et al, 2008) and clearance of insoluble protein aggregates (Lee et al, 2010).…”