title: [Effect of Plk1 330/597 serine phosphorylated mutant on cytokinesis during mitosis].
abstract: OBJECTIVE
  To explore the locations of pseudo-phosphorylated mutant (Plk1(S330/597D);) and non-phosphorylatable mutant (Plk1(S330/597A);) of Plk1 (residues 330 and 597 serine) in HeLa cells and the effect on mitosis.
  
  
  METHODS
  We transfected wide-type Plk1-GFP,  Plk1(S330/597D);-GFP and Plk1(S330/597A);-GFP into HeLa cells,  respectively,  and detected the locations of wide type and mutants in HeLa cells using immunofluorescence staining and the protein expressions of Plk1(S330/597D);-GFP and Plk1(S330/597A);-GFP with immunoblotting. HeLa cells transfected with Plk1 mutants were observed and analyzed in mitotic phase for cell count and cell cycle by flow cytometry.
  
  
  RESULTS
  The protein expressions of Plk1 mutants were verified. Immunofluorescence microscopy revealed that mutagenesis of these phosphorylation sites did not affect targeting of Plk1 to kinetochore and midbody during mitosis. However,  after transfection of Plk1(S330/597A);-GFP,  mitosis was inhibited and arrested at cytokinesis compared to control cells. Flow cytometry showed that Plk1(S330/597A);-GFP expression led to an increased G2/M arrest (P<0.01).
  
  
  CONCLUSIONS
  Non-phosphorylatable mutant of Plk1 (Plk1(S330/597A);) induces cytokinesis failure and causes the cell cycle arrest at G2/M phase.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Basic Medicine, Anhui Medical University, Hefei, China.
authors.forename: Li
authors.initials: L
authors.lastname: Cheng
authors.forename: Li-jian
authors.initials: LJ
authors.lastname: Chen
authors.forename: Ran
authors.initials: R
authors.lastname: An
authors.forename: Jian
authors.initials: J
authors.lastname: Du
mesh_terms: D000595:Amino Acid Sequence; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D048749:Cytokinesis / Q000235:genetics*; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D012694:Serine / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012694:Serine; D000097869:Polo-Like Kinase 1