Resumen:
|
[EN] Peroxisomes are dynamic organelles and the sole location for fatty acid ß-oxidation in yeast cells. Here, we report that peroxisomal function is crucial for the adaptation to salt stress, especially upon sugar limitation. ...[+]
[EN] Peroxisomes are dynamic organelles and the sole location for fatty acid ß-oxidation in yeast cells. Here, we report that peroxisomal function is crucial for the adaptation to salt stress, especially upon sugar limitation. Upon stress, multiple layers of control regulate the activity and the number of peroxisomes. Activated Hog1 MAP kinase triggers the induction of genes encoding enzymes for fatty acid activation, peroxisomal import and ß-oxidation through the Adr1 transcriptional activator, which transiently associates with genes encoding fatty acid metabolic enzymes in a stress- and Hog1-dependent manner. Moreover, Na+ and Li+ stress increases the number of peroxisomes per cell in a Hog1-independent manner, which depends instead of the retrograde pathway and the dynamin related GTPases Dnm1 and Vps1. The strong activation of the Faa1 fatty acyl-CoA synthetase, which specifically localizes to lipid particles and peroxisomes, indicates that adaptation to salt stress requires the enhanced mobilization of fatty acids from internal lipid stores. Furthermore, the activation of mitochondrial respiration during stress depends on peroxisomes, mitochondrial acetyl-carnitine uptake is essential for salt resistance and the number of peroxisomes attached to the mitochondrial network increases during salt adaptation, which altogether indicates that stress-induced peroxisomal ß-oxidation triggers enhanced respiration upon salt shock.
peroxisomes, mitochondrial acetyl-carnitine uptake is essential for salt resistance, and the percentage of peroxisomes attached to the mitochondrial network increases during salt adaptation, which altogether indicates that stress-induced peroxisomal β-oxidation triggers enhanced respiration upon salt shock.
[-]
|
Agradecimientos:
|
We thank E. Hettema for the kind gift of GFP-PTS1 expressing yeast strains and E. de Nadal and F. Posas for the kind gift of Hog1-GFP wt and kinase dead alleles. This work was supported only in the initial phase by a grant ...[+]
We thank E. Hettema for the kind gift of GFP-PTS1 expressing yeast strains and E. de Nadal and F. Posas for the kind gift of Hog1-GFP wt and kinase dead alleles. This work was supported only in the initial phase by a grant from Ministerio de Economia y Competitividad (BFU2011-23326). The authors declare no conflict of interest. MP and AP-A conceived and designed the study, SM-E, JE-B, BA, MP and AP-A acquired, analyzed and interpreted data, MP wrote the manuscript.
[-]
|