The invention discloses 432 novel acetylation sites identified in signal transduction proteins and pathways underlying human protein acetylation signaling pathways, and provides acetylation-site specific antibodies and heavy-isotope labeled peptides (AQUA peptides) for the selective detection and quantification of these acetylated sites/proteins, as well as methods of using the reagents for such purpose. Among the acetylation sites identified are sites occurring in the following protein types: Acetyltransferases, Adaptor/Scaffold proteins, Actin binding proteins, Adhesion proteins, Apoptosis proteins, Calcium-binding proteins, Cell Cycle Regulation proteins, Cell Surface proteins, DNA binding proteins, DNA replication proteins, Channel proteins, Chaperone proteins, Cellular Metabolism enzymes, Cytoskeletal proteins, DNA repair proteins, Endoplasmic reticulum proteins, Enzyme proteins, G protein and GTPase Activating proteins, Guanine Nucleotide Exchange Factors, Helicase proteins, Isomerase proteins, Extracelluar matrix proteins, Hydrolases, Ligase proteins, Lipid kinases, Inhibtor proteins, Lipid Binding proteins and Lyases.