The DNA-binding subunit p140 of replication factor C is upregulated in cycling cells and associates with G1 phase cell cycle regulatory proteins.
The DNA-binding subunit of replication factor C (RFCp140) plays an important role in both DNA replication and DNA repair. The mechanisms regulating activation of RFCp140 thereby controlling replication and cellular proliferation are largely unknown. We analyzed protein expression of RFCp140 during cell cycle progression and investigated the association of RFCp140 with cell cycle regulatory proteins in cell lines of various tissue origin and in primary hematopoietic cells. Western and Northern blot analyses of RFCp140 from synchronized cells showed downregulation of RFCp140 when cells enter a G0-like quiescent state and upregulation of RFCp140 in cycling cells. Translocation from the cytoplasmic compartment to the nucleus did not account for the significant increase in RFCp140 protein levels observed in cycling cells. To investigate a potential association of RFCp140 with cell cycle regulatory proteins coimmunoprecipitation assays were performed. These studies demonstrated specific binding of RFCp140 to cdk4-kinase in hematopoietic and fibroblast cell lines. Additional coimmunoprecipitation studies revealed specific association of RFCp140 with cyclin D1, p21, proliferating cell nuclear antigen, and retinoblastoma protein. These findings link DNA replication and repair factor RFCp140 to G1 phase cell cycle regulatory elements critically involved in cell cycle control.
van der Kuip
H
H
Department of Hematology, Johannes Gutenberg University School of Medicine, Mainz, Germany.
Carius
B
B
Haque
S J
SJ
Williams
B R
BR
Huber
C
C
Fischer
T
T
D016475:3T3 Cells; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D016193:G1 Phase; D018398:Homeodomain Proteins; D006801:Humans; D051379:Mice; D015778:Minor Histocompatibility Antigens; D019253:Proto-Oncogene Proteins c-bcl-2; D051818:Replication Protein C; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D013601:T-Lymphocytes / Q000378:metabolism; D015854:Up-Regulation
C096816:BCL2-related protein A1; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C096063:MATA1 protein, S cerevisiae; D015778:Minor Histocompatibility Antigens; D019253:Proto-Oncogene Proteins c-bcl-2; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D051818:Replication Protein C