title: Investigation on PLK2 and PLK3 substrate recognition.
abstract: Analyses of human phosphoproteome based on primary structure of the aminoacids surrounding the phosphor Ser/Thr suggest that a significant proportion of phosphosites is generated by a restricted number of acidophilic kinases, among which protein kinase CK2 plays a prominent role. Recently, new acidophilic kinases belonging to the Polo like kinase family have been characterized, with special reference to PLK1, PLK2, and PLK3 kinases. While some progress has been made in deciphering the PLK1-dependent phosphoproteome, very little is known about the targets of PLK2 and PLK3 kinases. In this report by using an in vitro approach, consisting of cell lysate phosphorylation, phosphoprotein separation by 2D gel electrophoresis and mass spectrometry, we describe the identification of new potential substrates of PLK2 and PLK3 kinases. We have identified and validated as in vitro PLK2 and PLK3 substrates HSP90, GRP-94, β-tubulin, calumenin, and 14-3-3 epsilon. The phosphosites generated by PLK3 in these proteins have been identified by mass spectrometry analysis to get new insights about PLKs specificity determinants. These latter have been further corroborated by an in silico analysis of the PLKs substrate binding region.
authors: Department of Biomedical Sciences, University of Padova, Italy. mauro.salvi@unipd.it
authors: M
authors: M
authors: Salvi
authors: E
authors: E
authors: Trashi
authors: G
authors: G
authors: Cozza
authors: C
authors: C
authors: Franchin
authors: G
authors: G
authors: Arrigoni
authors: L A
authors: LA
authors: Pinna
mesh_terms: D000595:Amino Acid Sequence; D002478:Cells, Cultured; D006801:Humans; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D025521:Tumor Suppressor Proteins; D000097868:Polo-like Kinases
chemical_list: D017346:Protein Serine-Threonine Kinases; D025521:Tumor Suppressor Proteins; C486256:PLK3 protein, human; D000097868:Polo-like Kinases; C496126:PLK2 protein, human