Inhibition of eukaryotic DNA replication by geminin binding to Cdt1

Science. 2000 Dec 22;290(5500):2309-12. doi: 10.1126/science.290.5500.2309.


In all eukaryotic organisms, inappropriate firing of replication origins during the G2 phase of the cell cycle is suppressed by cyclin-dependent kinases. Multicellular eukaryotes contain a second putative inhibitor of re-replication called geminin. Geminin is believed to block binding of the mini-chromosome maintenance (MCM) complex to origins of replication, but the mechanism of this inhibition is unclear. Here we show that geminin interacts tightly with Cdt1, a recently identified replication initiation factor necessary for MCM loading. The inhibition of DNA replication by geminin that is observed in cell-free DNA replication extracts is reversed by the addition of excess Cdt1. In the normal cell cycle, Cdt1 is present only in G1 and S, whereas geminin is present in S and G2 phases of the cell cycle. Together, these results suggest that geminin inhibits inappropriate origin firing by targeting Cdt1.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle Proteins / pharmacology
  • Cell Nucleus / metabolism
  • Cell-Free System
  • Chromatin / metabolism
  • DNA Replication*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / pharmacology
  • Evolution, Molecular
  • G1 Phase
  • G2 Phase
  • Geminin
  • HeLa Cells
  • Humans
  • Interphase*
  • Molecular Sequence Data
  • Molecular Weight
  • Precipitin Tests
  • Recombinant Fusion Proteins / metabolism
  • Replication Origin
  • S Phase*
  • Xenopus
  • Xenopus Proteins


  • CDT1 protein, human
  • Cell Cycle Proteins
  • Chromatin
  • DNA-Binding Proteins
  • GMNN protein, Xenopus
  • GMNN protein, human
  • Geminin
  • Recombinant Fusion Proteins
  • Xenopus Proteins

Associated data

  • GENBANK/AF321125