Cdk1 Phosphorylates SPAT-1/Bora to Promote Plk1 Activation in C. elegans and Human Cells

Cell Rep. 2016 Apr 19;15(3):510-518. doi: 10.1016/j.celrep.2016.03.049. Epub 2016 Apr 7.

Abstract

The conserved Bora protein is a Plk1 activator, essential for checkpoint recovery after DNA damage in human cells. Here, we show that Bora interacts with Cyclin B and is phosphorylated by Cyclin B/Cdk1 at several sites. The first 225 amino acids of Bora, which contain two Cyclin binding sites and three conserved phosphorylated residues, are sufficient to promote Plk1 phosphorylation by Aurora A in vitro. Mutating the Cyclin binding sites or the three conserved phosphorylation sites abrogates the ability of the N terminus of Bora to promote Plk1 activation. In human cells, Bora-carrying mutations of the three conserved phosphorylation sites cannot sustain mitotic entry after DNA damage. In C. elegans embryos, mutation of the three conserved phosphorylation sites in SPAT-1, the Bora ortholog, results in a severe mitotic entry delay. Our results reveal a crucial and conserved role of phosphorylation of the N terminus of Bora for Plk1 activation and mitotic entry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / metabolism
  • Animals
  • CDC2 Protein Kinase / metabolism*
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / enzymology*
  • Caenorhabditis elegans Proteins / chemistry
  • Caenorhabditis elegans Proteins / metabolism*
  • Cell Cycle Checkpoints
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Conserved Sequence
  • Cyclin B / metabolism
  • DNA Damage
  • Embryo, Nonmammalian / cytology
  • Enzyme Activation
  • HeLa Cells
  • Humans
  • Mitosis
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*

Substances

  • Amino Acids
  • Caenorhabditis elegans Proteins
  • Cell Cycle Proteins
  • Cyclin B
  • Proto-Oncogene Proteins
  • SPAT-1 protein, C elegans
  • bora protein, human
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1
  • CDC2 Protein Kinase