Identification, characterization and chromosomal localization of the cognate human and murine DBF4 genes.
The kinase Dbf4p/Cdc7p is required for the G1/S phase transition during the cell cycle and plays a direct role in the activation of individual origins of replication in Saccharomyces cerevisiae. Here, we report the identification and characterization of mouse and human cDNAs whose products are related in sequence to Saccharomyces cerevisiae DBF4 cDNA. Both mammalian Dbf4 proteins contain a putative site for phosphorylation by CDK, PEST protease cleavage sites, nuclear localization signals and a short-looped zinc finger-like domain. Transcription of MmDBF4 is suppressed in mouse NIH3T3 fibroblasts made quiescent by serum starvation. Upon replenishment of the medium, transcript levels increase during progression through G1, peaking as cells enter S phase. MmDbf4p interacts physically with Cdc7p and Mcm2p in vivo. Using fluorescence in situ hybridization (FISH), the human DBF4 gene was localized to chromosome 7 (q21.3), whereas FISH mapped the murine counterpart to band A2 on chromosome 5. The results of chromosome mapping indicate that in both mouse and human the gene is present as a single copy. The structural conservation between Dbf4-related proteins suggests that these proteins play a key role in the regulation of DNA replication during the cell cycle in all eukaryotes.
Lepke
M
M
Institute of Biochemistry, Biozentrum, University of Würzburg, Germany.
Pütter
V
V
Staib
C
C
Kneissl
M
M
Berger
C
C
Hoehn
K
K
Nanda
I
I
Schmid
M
M
Grummt
F
F
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D002897:Chromosomes, Human, Pair 7; D004261:DNA Replication; D018076:DNA, Complementary; D005656:Fungal Proteins; D006801:Humans; D051379:Mice; D064111:Minichromosome Maintenance Complex Component 2; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
D018797:Cell Cycle Proteins; C485678:DBF4 protein, human; C121983:DBF4 protein, mouse; D018076:DNA, Complementary; C088096:Dbf4 protein, S cerevisiae; D005656:Fungal Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C489404:CDC7 protein, S cerevisiae; C068619:CDC7 protein, human; C489403:Cdc7 protein, mouse; D017346:Protein Serine-Threonine Kinases; D064111:Minichromosome Maintenance Complex Component 2