Expression, nuclear localization and interactions of human MCM/P1 proteins.
We report here the comparative analysis of human Mcm/P1 proteins (HsMcm2, -3, -5 and -7), including a characterization of their mutual interactions, cell cycle dependent expression and nuclear localization during the cell cycle and the quiescent state. The mRNA levels of these genes, which undergo cell cycle dependent oscillations with a peak at G1/S phase, may be regulated by E2F motifs, two of which were detected in the 5' upstream region of the HsMCM5 gene. In contrast, the protein levels of these Mcm proteins were found to remain rather constant during the HeLa cell cycle. However, their levels gradually increased in a variable manner as KD cells progressed from GO into the G1/S phase. In the GO stage, the amounts of HsMcm2 and -5 proteins were much lower than those of HsMcm7 and -3 proteins, suggesting that they are not present in stoichiometric amounts, and that only a proportion of these molecules actively participate in cell cycle regulation as part of Mcm/P1 complexes.
Tsuruga
H
H
Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, Suita City, Japan.
Yabuta
N
N
Hashizume
K
K
Ikeda
M
M
Endo
Y
Y
Nojima
H
H
D000595:Amino Acid Sequence; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D004261:DNA Replication; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D009687:Nuclear Proteins