Localization of cyclin A at the sites of cellular DNA replication.
Cyclin A is a nuclear protein which is part of a kinase complex with either p34cdc2 or p33cdk2. Cyclin A is required in higher eukaryotic cells at the G1/S and the G2/M transitions. To examine the relationship between cyclin A and DNA replication, we simultaneously labeled exponentially growing HeLa cells for the distribution of cyclin A and proliferating cell nuclear antigen (PCNA). We have now demonstrated, by means of immunoelectron microscopy, that cyclin A is located at the sites of DNA replication visualized by both BrdU and PCNA labeling. Thus cyclin A may play a significant role in the phosphorylation of proteins at or near the sites of DNA replication.
Sobczak-Thepot
J
J
INSERM U370, Faculte Necker, Paris, France.
Harper
F
F
Florentin
Y
Y
Zindy
F
F
Brechot
C
C
Puvion
E
E
D001973:Bromodeoxyuridine / Q000378:metabolism; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D016213:Cyclins / Q000032:analysis* / Q000502:physiology; D004247:DNA / Q000378:metabolism; D004261:DNA Replication; D006367:HeLa Cells; D006801:Humans; D016253:Microscopy, Immunoelectron; D009687:Nuclear Proteins / Q000032:analysis; D010766:Phosphorylation; D018809:Proliferating Cell Nuclear Antigen
D016213:Cyclins; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D004247:DNA; D001973:Bromodeoxyuridine