Abstract: The invention discloses 142 novel phosphorylation sites identified in insulin signaling pathways, peptides (including AQUA peptides) comprising a phosphorylation site of the invention, antibodies specifically bind to a novel phosphorylation site of the invention, and diagnostic and therapeutic uses of the above.

Abstract: 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.

Abstract: The invention discloses 482 novel phosphorylation sites identified in carcinoma and/or leukemia, peptides (including AQUA peptides) comprising a phosphorylation site of the invention, antibodies specifically bind to a novel phosphorylation site of the invention, and diagnostic and therapeutic uses of the above.

Abstract: The invention discloses 364 novel phosphorylation sites identified in carcinoma, peptides (including AQUA peptides) comprising a phosphorylation site of the invention, antibodies specifically bind to a novel phosphorylation site of the invention, and diagnostic and therapeutic uses of the above.

Abstract: The invention discloses 405 novel phosphorylation sites identified in carcinoma and/or leukemia, peptides (including AQUA peptides) comprising a phosphorylation site of the invention, antibodies specifically bind to a novel phosphorylation site of the invention, and diagnostic and therapeutic uses of the above.

Abstract: The invention discloses ten newly discovered PI3K regulatory subunit phosphorylation sites, tyrosines 467, 452, 463, and 470 in PI3KR1 (PI3Kp85 alpha), tyrosines 464, 460, and 467 in PI3KR2 (PI3Kp85 beta), and tyrosines 199, 184, and 202 in PI3KR3 (PI3Kp55 gamma), and provides reagents, including polyclonal and monoclonal antibodies, that selectively bind to PI3K when phosphorylated at one of the disclosed sites. Also provided are assays utilizing this reagent, including methods for determining the phosphorylation of PI3K in a biological sample, selecting a patient suitable for PI3K inhibitor therapy, profiling PI3K activation in a test tissue, and identifying a compound that modulates phosphorylation of PI3K in a test tissue, by using a detectable reagent, such as the disclosed antibody, that binds to PI3K only when phosphorylated at a disclosed site. The sample or test tissue may be taken from a subject suspected of having cancer, such as lymphoma, glioma, and colon cancer, involving altered PI3K signaling.

Abstract: A method is provided for producing motif-specific, context-independent antibodies that recognize a plurality of peptides or proteins within a genome that contain the same post-translationally modified motif. The method includes the step of immunizing a host with a degenerate peptide library antigen featuring (i) a fixed target motif containing one or more invariant amino acids including at least one modified amino acid, and (ii) a plurality of degenerate amino acids flanking the motif. Motif-specific, context-independent antibodies produced by the disclosed method are also provided. The method encompasses motifs consisting of a single modified amino acid, as well as short motifs comprising multiple invariant amino acids including one or more modified amino acids, such as all or part of kinase consensus substrate motifs, protein-protein binding motifs, or other cell signaling motifs. Methods of using the antibodies, e.g. for genome-wide profiling, are also provided.