title: Timeless links replication termination to mitotic kinase activation.
abstract: The mechanisms that coordinate the termination of DNA replication with progression through mitosis are not completely understood. The human Timeless protein (Tim) associates with S phase replication checkpoint proteins Claspin and Tipin, and plays an important role in maintaining replication fork stability at physical barriers, like centromeres, telomeres and ribosomal DNA repeats, as well as at termination sites. We show here that human Tim can be isolated in a complex with mitotic entry kinases CDK1, Auroras A and B, and Polo-like kinase (Plk1). Plk1 bound Tim directly and colocalized with Tim at a subset of mitotic structures in M phase. Tim depletion caused multiple mitotic defects, including the loss of sister-chromatid cohesion, loss of mitotic spindle architecture, and a failure to exit mitosis. Tim depletion caused a delay in mitotic kinase activity in vivo and in vitro, as well as a reduction in global histone H3 S10 phosphorylation during G2/M phase. Tim was also required for the recruitment of Plk1 to centromeric DNA and formation of catenated DNA structures at human centromere alpha satellite repeats. Taken together, these findings suggest that Tim coordinates mitotic kinase activation with termination of DNA replication.
authors.affiliation: The Wistar Institute, Philadelphia, Pennsylvania, United States of America.
authors.forename: Jayaraju
authors.initials: J
authors.lastname: Dheekollu
authors.forename: Andreas
authors.initials: A
authors.lastname: Wiedmer
authors.forename: James
authors.initials: J
authors.lastname: Hayden
authors.forename: David
authors.initials: D
authors.lastname: Speicher
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Gotter
authors.forename: Tim
authors.initials: T
authors.lastname: Yen
authors.forename: Paul M
authors.initials: PM
authors.lastname: Lieberman
mesh_terms: D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002503:Centromere / Q000378:metabolism; D002869:Chromosome Aberrations; D004261:DNA Replication; D004273:DNA, Neoplasm / Q000378:metabolism; D004789:Enzyme Activation; D004795:Enzyme Stability; D016195:G2 Phase; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency / Q000378:metabolism*; D008677:Metaphase; D008938:Mitosis; D008954:Models, Biological; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021381:Protein Transport; D040901:Proteomics; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D004273:DNA, Neoplasm; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1; C509769:TIMELESS protein, human