We propose a carbon source dependent genetic regulatory network for the budding yeast Saccharomyces cerevisiae, derived from quantitative proteomic analyses integrated with bioinformatics knowledge of regulatory pathways and protein interactions. The proposed network, comprising 1247 transcription factor interactions and 126 chaperone interactions, defines the proteome shift in the cell when growing under different carbon sources. We used a label-free proteomics strategy to quantify alterations in protein abundance for S. cerevisiae when grown on minimal media using glucose, galactose, maltose and trehalose as sole carbon sources.