The transcription of ribosomal RNA genes (rDNA) is a rate-limiting step in ribosome biogenesis and changes profoundly in response to environmental conditions. Recently we reported that JmjC demethylase KDM2A reduces rDNA transcription on starvation, with accompanying demethylation of dimethylated Lys 36 of histone H3 (H3K36me2) in rDNA promoter. Here, we characterized the functions of two domai...

Cell populations of the marine bacterium ANT-300, from either batch or continuous culture with dilution rates ranging from D = 0.015 h to D = 0.200 h, were monitored for viability, direct counts, and optical density for 98 days under starvation conditions. Three stages of starvation survival were observed for each of the cell populations. Although direct counts remained at 2 x 10 to 3 x 10 cell...

A fundamental question in life-history evolution is how organisms cope with fluctuating environments, including variation between stressful and benign conditions. For short-lived organisms, environments commonly vary between generations. Using a novel experimental design, we exposed wild-derived Drosophila melanogaster to three different selection regimes: one where generations alternated betwe...

When inorganic phosphate is limiting, Arabidopsis has the facultative ability to metabolize exogenous nucleic acid substrates, which we utilized previously to identify insensitive phosphate starvation response mutants in a conditional genetic screen. In this study, we examined the effect of the phosphate analog, phosphite (Phi), on molecular and morphological responses to phosphate starvation. ...

Serum starvation is a common cell culture procedure for increasing cellular response to insulin, though the mechanism for the serum starvation effect is not understood. We hypothesized that factors known to potentiate insulin action [e.g., AMP-activated protein kinase (AMPK) and p38] or to be involved in insulin signaling leading to glucose transport [e.g., Akt, PKCζ, AS160, and ataxia telangie...

Nitrogen starvation has been shown to increase the cytosolic arginine concentration and to accelerate protein turnover in mycelia of Neurospora crassa. The cytosolic arginine is derived from a metabolically inactive vacuolar pool. Redistribution of arginine between cytosolic and vacuolar compartments is the result of mobilization of this metabolite in response to nitrogen starvation. Mobilizati...

Upon starvation cells undergo autophagy, a cellular degradation pathway important in the turnover of whole organelles and long lived proteins. Starvation-induced protein degradation has been regarded as an unspecific bulk degradation process. We studied global protein dynamics during amino acid starvation-induced autophagy by quantitative mass spectrometry and were able to record nearly 1500 pr...