Quantitative phospho-proteomics to investigate the polo-like kinase 1-dependent phospho-proteome.

TitleQuantitative phospho-proteomics to investigate the polo-like kinase 1-dependent phospho-proteome.
Publication TypeJournal Article
Year of Publication2011
AuthorsGrosstessner-Hain, K, Hegemann, B, Novatchkova, M, Rameseder, J, Joughin, BA, Hudecz, O, Roitinger, E, Pichler, P, Kraut, N, Yaffe, MB, Peters, J-M, Mechtler, K
JournalMol Cell Proteomics
Date Published2011 Nov
KeywordsAmino Acid Motifs, Amino Acid Sequence, Cell Cycle, Cell Cycle Proteins, Computational Biology, Consensus Sequence, HeLa Cells, Humans, Molecular Sequence Data, Phosphoproteins, Protein Kinase Inhibitors, Protein-Serine-Threonine Kinases, Proteome, Proteomics, Proto-Oncogene Proteins

Polo-like kinase 1 (PLK1) is a key regulator of mitotic progression and cell division, and small molecule inhibitors of PLK1 are undergoing clinical trials to evaluate their utility in cancer therapy. Despite this importance, current knowledge about the identity of PLK1 substrates is limited. Here we present the results of a proteome-wide analysis of PLK1-regulated phosphorylation sites in mitotic human cells. We compared phosphorylation sites in HeLa cells that were or were not treated with the PLK1-inhibitor BI 4834, by labeling peptides via methyl esterification, fractionation of peptides by strong cation exchange chromatography, and phosphopeptide enrichment via immobilized metal affinity chromatography. Analysis by quantitative mass spectrometry identified 4070 unique mitotic phosphorylation sites on 2069 proteins. Of these, 401 proteins contained one or multiple phosphorylation sites whose abundance was decreased by PLK1 inhibition. These include proteins implicated in PLK1-regulated processes such as DNA damage, mitotic spindle formation, spindle assembly checkpoint signaling, and chromosome segregation, but also numerous proteins that were not suspected to be regulated by PLK1. Analysis of amino acid sequence motifs among phosphorylation sites down-regulated under PLK1 inhibition in this data set identified two potential novel variants of the PLK1 consensus motif.

Alternate JournalMol. Cell Proteomics
PubMed ID21857030
PubMed Central IDPMC3226402
Grant ListES015339 / ES / NIEHS NIH HHS / United States
U54-CA112967 / CA / NCI NIH HHS / United States