A Novel Human Mcm Protein: Homology to the Yeast Replication Protein Mis5 and Chromosomal Location

Holthoff, Hans Peter; Hameister, Horst; Knippers, Rolf

doi:10.1006/geno.1996.0530

Cited by 18 publications

(14 citation statements)

References 2 publications

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“…Very recently, two complete human cDNA sequences have appeared on the databases [19,20] and these both also show 99% identity to the sequences reported here.…”

Section: Construction Of a Composite Cdna From Est Sequencessupporting

confidence: 68%

Characterisation of a human homologue of a yeast cell division cycle gene, MCM6, located adjacent to the 5′ end of the lactase gene on chromosome 2q21

Harvey¹,

Wang²,

Darmoul

et al. 1996

FEBS Letters

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“…Very recently, two complete human cDNA sequences have appeared on the databases [19,20] and these both also show 99% identity to the sequences reported here.…”

Section: Construction Of a Composite Cdna From Est Sequencessupporting

confidence: 68%

Characterisation of a human homologue of a yeast cell division cycle gene, MCM6, located adjacent to the 5′ end of the lactase gene on chromosome 2q21

Harvey¹,

Wang²,

Darmoul

et al. 1996

FEBS Letters

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“…2 Therefore, I speculate that a complex consisting of MCM2, -4, -6, and -7 was bound to the histone-Sepharose column through the interaction between MCM2 and histone (histone H3), and a trimeric complex of MCM4, -6, and -7 was dissociated from MCM2 protein during the elution of the MCM proteins with sodium chloride. Knipper's group (12,15,16) has reported that MCM4, -6, and -7 proteins form a stable complex and that MCM2 protein is more loosely associated with the trimeric form of MCM proteins. My conclusion that a hexamer of MCM4, -6, and -7 has DNA helicase activity is consistent with the findings that several helicases including SV40 T antigen (30) function as a hexamer (31)(32)(33).…”

Section: Fig 3 Protein Cross-linking Of MCM Proteins a The Pooledmentioning

confidence: 99%

“…Interaction between the MCM proteins has been reported in yeast (4, 7), and the protein complexes containing MCM proteins are detected in Drosophila (8), Xenopus (9), mouse (10, 11), and human cells (12)(13)(14). In human cells, MCM4, -6, and -7 proteins form a stable complex, and MCM2 is loosely associated with this complex (12,15,16). MCM3 and -5 proteins also form a stable complex (10, 13).…”

mentioning

confidence: 99%

A DNA Helicase Activity Is Associated with an MCM4, -6, and -7 Protein Complex

Ishimi

1997

Journal of Biological Chemistry

506

508

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All six minichromosome maintenance (MCM) proteins have DNA-dependent ATPase motifs in the central domain which is conserved from yeast to mammals. Our group purified MCM protein complexes consisting of MCM2, -4 (Cdc21), -6 (Mis5), and -7 (CDC47) proteins from HeLa cells by using histone-Sepharose column chromatography (Ishimi, Y., Ichinose, S., Omori, A., Sato K., and Kimura, H. (1996) J. Biol. Chem. 271, 24115-24122). The present study revealed that both ATPase activity and DNA helicase activity that displaces oligonucleotides annealed to single-stranded circular DNA are associated with an MCM protein complex. Both ATPase and DNA helicase activities were co-purified with a 600-kDa protein complex that is consisted of equal amounts of MCM4, -6, and -7 proteins. An immunodepletion of the MCM protein complex from the purified fraction using anti-MCM4 antibody resulted in the severe reduction of the DNA helicase activity. Displacement of DNA fragments by the DNA helicase suggested that it migrated along single-stranded DNA in the 3 to 5 direction, and the DNA helicase activity was detected only in the presence of hydrolyzable ATP or dATP. These results suggest that this helicase may be involved in the initiation of DNA replication as a DNA unwinding enzyme.There are at least six MCM 1 proteins that play an essential role in eukaryotic DNA replication as follows: MCM2, -3, -4 (Cdc21), -5, -6 (Mis5), and -7 (CDC47) proteins (see reviews in Refs. 1-3). Genetic evidence suggests that these proteins are required for the initiation of DNA replication in yeast (4, 5). The inactivation of human MCM2 protein with antibody consistently inhibits the initiation of DNA replication (6). Interaction between the MCM proteins has been reported in yeast (4, 7), and the protein complexes containing MCM proteins are detected in Drosophila (8), Xenopus (9), mouse (10, 11), and human cells (12)(13)(14). In human cells, MCM4, -6, and -7 proteins form a stable complex, and MCM2 is loosely associated with this complex (12,15,16). MCM3 and -5 proteins also form a stable complex (10, 13). All six of the MCM proteins contain DNA-dependent ATPase motifs in a central domain that is conserved from yeast to mammals, and these motifs are found in several enzymes that unwind the DNA duplex (17). These findings suggest that MCM protein complexes may be involved in the initiation of DNA replication as an enzyme that unwinds DNA in the origin region. However, DNA helicase activity of MCM proteins has not been reported.MCM proteins bind with chromatin before the initiation of DNA replication and are then released from the chromatin as DNA replication proceeds (18 -20). Our group found that MCM protein complexes containing MCM2, -4, -6, and -7 proteins bound tightly with histone H3 in vitro and were purified to near homogeneity by histone-Sepharose column chromatography (21). In the present study, it is shown that both ATPase and DNA helicase activities are associated with an MCM4, -6, and -7 protein complex. EXPERIMENTAL PROCEDURESPurification of MCM ...

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“…Based on the molecular mass of each MCM protein, this complex is probably a hexamer containing a single molecule of the six MCM proteins. However, sub-complexes containing MCM2, -4, -6, and -7 or MCM3 and -5 have also been isolated from human cell extracts (13)(14)(15)(16)(17), Xenopus egg extracts (18), and mouse cell extracts (19). Our group recently found that the DNA helicase activity was associated with the human MCM4, -6, and -7 protein complex (20).…”

mentioning

confidence: 99%

Biochemical Function of Mouse Minichromosome Maintenance 2 Protein

Ishimi¹,

Komamura²,

You³

et al. 1998

Journal of Biological Chemistry

134

138

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Minichromosome maintenance (MCM) proteins play an essential role in eukaryotic DNA replication and bind to chromatin before the initiation of DNA replication. We reported that MCM protein complexes consisting of MCM2, -4, -6, and -7 bind strongly to a histone-Sepharose column (Ishimi, Y., Ichinose, S., Omori, A., Sato, K., and Kimura, H. (1996) J. Biol. Chem. 271, 24115-24122). Here, we have analyzed this interaction at the molecular level. We found that among six mouse MCM proteins, only MCM2 binds to histone; amino acid residues 63-153 are responsible for this binding. The region required for nuclear localization of MCM2 was mapped near this histone-binding domain. Far-Western blotting analysis of truncated forms of H3 histone indicated that amino acid residues 26 -67 of H3 histone are required for binding to MCM2. We have also shown that mouse MCM2 can inhibit the DNA helicase activity of the human MCM4, -6, and -7 protein complex. These results suggest that MCM2 plays a different role in the initiation of DNA replication than the other MCM proteins. Minichromosome maintenance (MCM)1 proteins play an essential role in eukaryotic DNA replication. Six MCM proteins (MCM2-7) have been identified from yeast to mammals, and each of them plays a distinct role in DNA replication (reviewed in Refs. 1-3). Several lines of evidence suggest that MCM proteins are required for the initiation of DNA replication (4 -6). Consistent with this idea, MCM proteins associate with the chromatin before the onset of DNA replication and detach from the chromatin during DNA replication (7-9). Biochemical analyses have indicated that these six MCM proteins interact. In extracts from Schizosaccharomyces pombe (10), mouse cells (11) and mitotic human cells (12), a complex of approximately 600 kDa, containing all six MCM proteins, have been identified. Based on the molecular mass of each MCM protein, this complex is probably a hexamer containing a single molecule of the six MCM proteins. However, sub-complexes containing MCM2, -4, -6, and -7 or MCM3 and -5 have also been isolated from human cell extracts (13-17), Xenopus egg extracts (18), and mouse cell extracts (19). Our group recently found that the DNA helicase activity was associated with the human MCM4, -6, and -7 protein complex (20). The 600-kDa complex containing the six MCM proteins is detected in soluble cell extracts; however, the structures of the chromatin-bound MCM protein heterocomplexes (21) remain to be elucidated.Origin recognition complex (ORC) and CDC6 protein are both required for the initiation of DNA replication and are necessary for the binding of MCM proteins to chromatin in Xenopus egg extracts (22, 23). CDC6-dependent loading of MCM proteins onto chromatin (24, 25) and origins (26, 27) has also been observed in Saccharomyces cerevisiae. The genetic interaction between MCM proteins and ORC in S. cerevisiae supports these findings (28, 29). These results suggest that MCM proteins form a complex with ORC and CDC6 at the replication origin. In S. cerevisiae the numb...

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A Novel Human Mcm Protein: Homology to the Yeast Replication Protein Mis5 and Chromosomal Location

Cited by 18 publications

References 2 publications

Characterisation of a human homologue of a yeast cell division cycle gene, MCM6, located adjacent to the 5′ end of the lactase gene on chromosome 2q21

Characterisation of a human homologue of a yeast cell division cycle gene, MCM6, located adjacent to the 5′ end of the lactase gene on chromosome 2q21

A DNA Helicase Activity Is Associated with an MCM4, -6, and -7 Protein Complex

Biochemical Function of Mouse Minichromosome Maintenance 2 Protein

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