Large-scale characterization of HeLa cell nuclear phosphoproteins.
Determining the site of a regulatory phosphorylation event is often essential for elucidating specific kinase-substrate relationships, providing a handle for understanding essential signaling pathways and ultimately allowing insights into numerous disease pathologies. Despite intense research efforts to elucidate mechanisms of protein phosphorylation regulation, efficient, large-scale identification and characterization of phosphorylation sites remains an unsolved problem. In this report we describe an application of existing technology for the isolation and identification of phosphorylation sites. By using a strategy based on strong cation exchange chromatography, phosphopeptides were enriched from the nuclear fraction of HeLa cell lysate. From 967 proteins, 2,002 phosphorylation sites were determined by tandem MS. This unprecedented large collection of sites permitted a detailed accounting of known and unknown kinase motifs and substrates.
Beausoleil
Sean A
SA
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Jedrychowski
Mark
M
Schwartz
Daniel
D
Elias
Joshua E
JE
Villén
Judit
J
Li
Jiaxu
J
Cohn
Martin A
MA
Cantley
Lewis C
LC
Gygi
Steven P
SP
D000595:Amino Acid Sequence; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D019295:Computational Biology; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010766:Phosphorylation; D012694:Serine / Q000737:chemistry; D013912:Threonine / Q000737:chemistry; D014357:Trypsin
D009687:Nuclear Proteins; D010750:Phosphoproteins; D013912:Threonine; D012694:Serine; D014357:Trypsin