Related Experiment Video
Updated: Jul 18, 2026

Experimental Approaches to Study Mitochondrial Localization and Function of a Nuclear Cell Cycle Kinase, Cdk1
Published on: February 25, 2016
Inhibition of eukaryotic DNA replication by geminin binding to Cdt1
J A Wohlschlegel1, B T Dwyer, S K Dhar
1Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
Abstract:
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.
More Related Videos
08:33Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis
Published on: December 5, 2017
09:56Epigenetic Engineering of K562 Cells: Dual-Vector Episomal Strategy for Stable Targeted DNA Methylation using dCas9-DNMT3A and -HDAC1 Fusion Proteins
Published on: October 31, 2025
Related Concept Videos
Negative Regulator Molecules
DNA Damage can Stall the Cell Cycle
Inhibition of Cdk Activity
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
DNA Damage Can Stall the Cell Cycle
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.