Dietary restriction (DR) has long been known to increase longevity of numerous species, although the exact mechanisms to this long lived phenotype are still to be identified. Through recent years, several phenotypic screens have been applied in order to uncover key regulatory molecules and pathways that are involved in this positive outcome. Based on that, processes like autophagy, lipid turnover and the generation/clearance of reactive oxygen species (ROS) have all been describe to affect life span, either alone, or in a not fully characterized interplay. The baker’s yeast Saccharomyces cerevisae is by now the organism with the best characterized proteome and is therefore the organism of choice in many proteomic studies. Additionally, this single-celled organism exhibits many conserved proteins and pathways of higher animals, thus observations in the yeast might reveal important information applying to other eukaryotes as well. Here we have used an unbiased mass spectrometry and a stable isotope labelling based approach in order to examine how cells respond to amino acid starvation. Furthermore, since most cellular pathways are regulated by reversible protein phosphorylation, we wish to combine quantitative mass spectrometry with site-specific proteomic approaches in order to monitor changes in post-translational modifications incl. phosphorylations in amino acid starved cells. We present results showing some of the novel pathways and proteins that might be of great importance during amino acid starvation.