Proteomic screen finds pSer/pThr-binding domain localizing Plk1 to mitotic substrates.
We have developed a proteomic approach for identifying phosphopeptide binding domains that modulate kinase-dependent signaling pathways. An immobilized library of partially degenerate phosphopeptides biased toward a particular protein kinase phosphorylation motif is used to isolate phospho-binding domains that bind to proteins phosphorylated by that kinase. Applying this approach to cyclin-dependent kinases (Cdks), we identified the polo-box domain (PBD) of the mitotic kinase polo-like kinase 1 (Plk1) as a specific phosphoserine (pSer) or phosphothreonine (pThr) binding domain and determined its optimal binding motif. This motif is present in known Plk1 substrates such as Cdc25, and an optimal phosphopeptide containing the motif disrupted PBD-substrate binding and localization of the PBD to centrosomes. This finding reveals how Plk1 can localize to specific sites within cells in response to Cdk phosphorylation at those sites and provides a structural mechanism for targeting the Plk1 kinase domain to its substrates.
Elia
Andrew E H
AE
Center for Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Cantley
Lewis C
LC
Yaffe
Michael B
MB
D020816:Amino Acid Motifs; D001665:Binding Sites; D002151:Calorimetry; D018797:Cell Cycle Proteins; D018385:Centrosome / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008024:Ligands; D008938:Mitosis; D019151:Peptide Library; D010748:Phosphopeptides / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D010769:Phosphothreonine / Q000378:metabolism*; D017354:Point Mutation; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary; D040901:Proteomics; D011518:Proto-Oncogene Proteins; D015398:Signal Transduction; D020687:cdc25 Phosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
D018797:Cell Cycle Proteins; D008024:Ligands; D019151:Peptide Library; D010748:Phosphopeptides; D010768:Phosphoserine; D010769:Phosphothreonine; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D020687:cdc25 Phosphatases; D000097869:Polo-Like Kinase 1