Sir2 plays a key role in cell fate determination upon SAPK activation

Sir2 histone deacetylase prevents programmed cell death caused by sustained activation of the Hog1 stress-activated protein kinase

Exposure of yeast to high osmolarity induces a transient activation of the Hog1 stress-activated protein kinase (SAPK), which is required for cell survival under these conditions. However, sustained activation of the SAPK results in a severe growth defect. We found that prolonged SAPK activation leads to cell death, which is not observed in nma111 cells, by causing accumulation of reactive oxyg...

Control of Ubp3 ubiquitin protease activity by the Hog1 SAPK modulates transcription upon osmostress

Protein ubiquitylation is a key process in the regulation of many cellular processes. The balance between the activity of ubiquitin ligases and that of proteases controls the level of ubiquitylation. In response to extracellular stimuli, stress-activated protein kinases (SAPK) modulate gene expression to maximize cell survival. In yeast, the Hog1 SAPK has a key role in reprogramming the gene ex...

Sir2 histone deacetylase prevents programmed cell death caused by sustained activation of the Hog1 SAPK

PLENARY PAPER Requirement of Activation of JNK and p38 for Environmental Stress-Induced Erythroid Differentiation and Apoptosis and of Inhibition of ERK for Apoptosis

C-Jun amino terminal kinase/stress-activated protein kinases (JNK/SAPK) and p38 subgroups of mitogen-activated protein kinases have been suggested to play a critical role in apoptosis, cell growth, and/or differentiation. We found that a short exposure of SKT6 cells, which respond to erythropoietin (Epo) and induce erythroid differentiation, to osmotic or heat shock induced transient activation...

Drosophila Sir2 Is Required for Heterochromatic Silencing and by Euchromatic Hairy/E(Spl) bHLH Repressors in Segmentation and Sex Determination

Yeast SIR2 is a NAD+-dependent histone deacetylase required for heterochromatic silencing at telomeres, rDNA, and mating-type loci. We find that the Drosophila homolog of Sir2 (dSir2) also encodes deacetylase activity and is required for heterochromatic silencing, but unlike ySir2, is not required for silencing at telomeres. We show that dSir2 interacts genetically and physically with members o...