Tps1 regulates CCR in response to G6P sensing.
2012-05-03T00:54:30Z (GMT) by
<p>(A) CCR is Tps1 dependent. Strains were grown for 10 days on CM or minimal media supplemented with 10 mM of the appropriate carbon and nitrogen source. Like Δ<i>nut1</i>, Δ<i>tps1</i> and Δ<i>tps1 Δnut1</i> strains are unable to utilize nitrate as nitrogen source. However, deleting the <i>TPS1</i> gene in Δ<i>nut1</i> strains restores growth on proline and glucosamine as nitrogen sources, demonstrating that CCR is inactivated in Δ<i>tps1</i>- carrying strains. (B) G6P sensing by Tps1 activates CCR. To mitigate against AA evaporation, best results were obtained when Guy11, Δ<i>tps1</i> and Δ<i>tps1::R22G</i> strains were grown for 5 days on 85 mm petri dishes containing either glucose-rich minimal media with 55 mM glucose and 10 mM NH<sub>4</sub><sup>+</sup> as sole carbon and nitrogen sources, respectively, or the same medium supplemented with 100 mM of the toxic analogue allyl alcohol (AA). Δ<i>tps1</i> strains were sensitive to 100 mM allyl alcohol, indicating they are carbon derepressed (i.e. CCR is inactivated) in the presence of glucose. Like Guy11, Δ<i>tps1::R22G</i> strains were not sensitive to 100 mM allyl alcohol, suggesting CCR operates correctly in the Δ<i>tps1::R22G</i> G6P sensing strains. (C) G6P sensing by Tps1 is the trigger for CCR resulting in the inhibition of alternative carbon source (Alt C) utilization by <i>M. oryzae</i>.</p>