Arsenic speciation in different fission yeast mutants.

<p>Total cell extracts from 5×10⁷ cells and growth media from wild type, <i>spc1</i>Δ, <i>cdc2-3w</i> and <i>cdc25</i>Δ <i>cdc2-3w</i> strains were obtained after treatment for 3 or 9 hours with 100 µM sodium arsenate. Graph shows the amount of As (V) (A) or As (III) (B) present in the extracts or growth media.</p

Instrumental parameters for As determination by LC/ICP/MS.

<p>Instrumental parameters for As determination by LC/ICP/MS.</p

Genotypes of <i>Schizosaccharomyces pombe</i> strains used in this work.

<p>Genotypes of <i>Schizosaccharomyces pombe</i> strains used in this work.</p

Cdc25 is essential for the response to arsenate.

<p>A. Arsenate to arsenite conversion in fission yeast. Cell extracts from cells treated with 100 µM sodium arsenate were analyzed for the presence of As (III) at different time points. Graph represents parts per million (ppm) As (III). B. Protein alignment of a fragment of <i>S. pombe</i> Cdc25, rice Cdc25 and <i>S. cerevisiae</i> Acr2 and human Cdc25. Asterisks indicate full conservation. C. Serial dilutions of wild type,<i>cdc2-3w</i> and <i>cdc2-3w cdc25</i>Δ strains were plated in rich media (YES) or rich media containing 25 µM sodium arsenate. Pictures were taken after incubation at 30°C for 48 hours. D. Western blotting of whole cell extracts from Cdc25:myc strains treated with 100 µM sodium arsenate for 0 to 180 minutes. Anti-myc antibodies were used to detect Cdc25:myc and anti-actin as a control. E. Total RNA from the experiment presented in (D) was purified and the total amount of Cdc25 mRNA quantified by qPCR. Actin mRNA was used as an internal control.</p

Spc1 MAPK pathway and the response to arsenate.

<p>A. Serial dilutions of wild type, <i>wis1</i>Δ, <i>mcs4</i>Δ, <i>wis4</i>Δ, <i>win1-1</i> and <i>wis4</i>Δ <i>win1-1</i> strains were plated in rich media (YES) or rich media containing 50 µM sodium arsenate. Pictures were taken after incubation at 30°C for 48 hours. B. Western blotting of purified Spc1 extracts from wild type, <i>wis1</i>Δ, <i>wis1-AA</i>, <i>win1-1, wis4</i>Δ, and <i>win1-1 wis4</i>Δ treated with 100 µM sodium arsenate for 0 to 30 minutes. Antibodies against phosphorylated p38 were used. As a control, antibodies against HA epitope were used. C. Western blotting of purified Spc1 extracts from wild type, <i>wis1</i>Δ, <i>win1-1 wis4</i>Δ, <i>win1-1 wis4</i>Δ <i>pyp1</i>Δ and <i>win1-1 wis4</i>Δ <i>pyp2</i>Δ treated with 100 µM sodium arsenate for 0 to 30 minutes. Antibodies against phosphorylated p38 were used. As a control, antibodies against HA epitope were used.</p

Graphite furnace programme.

<p>Graphite furnace programme.</p

Typical Chromatogram obtained for a standard solution of As species at 2.5 µg L⁻¹ using the experimental parameters summarized in Table 3.

<p>Peak 1: As (III); Peak 2: DMA; Peak 3: MMA; Peak 4: As (V).</p