Sulfide as a signaling molecule in autophagy

3 Páginas, 1 figuraHydrogen sulfide is already recognized as an important signaling molecule in mammalian systems, and emerging data suggest that H2S is a signaling molecule just as important as nitric oxide (NO) and H2O2 in plants. Although sulfide is generated in chloroplasts and mitochondria, it is present predominantly in the charged HS- form due to the basic pH inside both organelles, thus requiring an active transporter, which is yet to be identified, to be released. In Arabidopsis, we found that the cytosolic L-cysteine desulfhydrase DES1 is involved in the degradation of cysteine, and therefore responsible for the generation of H2S in this cellular compartment. DES1 deficiency leads to the induction of autophagy. Moreover, we have demonstrated that sulfide in particular exerts a general effect on autophagy through negative regulation, in a way unrelated to nutrient deficiency. The mechanisms of H2S action and its molecular targets are largely unknown, although in animal systems, protein Ssulfhydration has been proposed as a mechanism for sulfide-mediated signaling.This work was funded by the European Regional Development Fund and the Ministerio de Economia y Competitividad, Spain (Grants BIO2010-15201, BFU2012-35913 and CSD2007- 00057).Peer reviewe