High impact information on MCM10

• We show that Mcm10 is a chromatin-associated protein that mediates the association of the MCM2-7 complex with replication origins [1].
• In temperature-sensitive mcm10-td mutants, depletion of Mcm10 during S phase results in degradation of the catalytic subunit of polalpha, without affecting other fork components such as Cdc45 [2].
• Mcm10 is a conserved eukaryotic DNA replication factor whose function has remained elusive [2].
• We report here that Mcm10 binding to replication origins in budding yeast is cell cycle regulated and dependent on the putative helicase, Mcm2-7 [2].
• A fraction of Mcm10 binds to DNA, as shown by histone association assays that allow for the study of chromatin binding in vivo [2].

Biological context of MCM10

• BACKGROUND: MCM10 is essential for the initiation of chromosomal DNA replication in Saccharomyces cerevisiae [3].
• The Cdc23 (Mcm10) protein is required for the phosphorylation of minichromosome maintenance complex by the Dfp1-Hsk1 kinase [4].
• When exposed to alpha-factor, mcm10 mutant cells display a "shmoo-cluster" phenotype associated with a defect in the maintenance of silencing [5].
• In this study we demonstrate a role for Mcm10 in the maintenance of heterochromatic silencing at telomeres and HM loci of budding yeast [5].
• Two mcm10 mutants drastically reduce silencing of both URA3 and ADE2 reporter genes integrated into these silent loci [5].

Anatomical context of MCM10

• Mcm10p is an abundant protein (approximately 4 x 10(4) copies per haploid cell) that is almost exclusively localized in the chromatin and/or nuclear matrix fractions during all phases of the cell cycle [6].

Physical interactions of MCM10

• Mcm10p functionally interacts with components of the pre-replicative complex (Mcm2-Mcm7 complex and origin recognition complex) as well as the pre-initiation complex component (Cdc45p) suggesting that it may be a component of the pre-RC as well as the pre-IC [3].
• Moreover, overexpressed Cdc17 that is normally subject to rapid degradation is stabilized by Mcm10 co-overexpression but not by co-overexpression of the B-subunit of pol-alpha, Pol12 [7].
• A motif search revealed a match to the proliferating cell nuclear antigen (PCNA)-interacting protein (PIP) box in Mcm10 [8].

Regulatory relationships of MCM10

• Furthermore, mutations in MCM10 inhibit the ability of GBD-SIR3 to restore silencing when tethered to a defective HMR-E [5].
• Fission yeast Cdc23/Mcm10 functions after pre-replicative complex formation to promote Cdc45 chromatin binding [9].

Other interactions of MCM10

• Consistent with a direct silencing function, Mcm10p shows a two-hybrid interaction with Sir2p and Sir3p that is destroyed by the mcm10-1 mutation and dependent on the C-terminal 108 amino acids [5].
• We screened for mutations that are lethal in combination with mcm10-1 and obtained seven mutants named slm1-slm6 for synthetically lethal with mcm10 [3].
• DNA sequence analysis suggested that DNA43 and DNA52 encode proteins of 59.6 and 80.6 kDa, respectively [10].
• The high degree of evolutionary conservation of this domain implies that stabilizing Cdc17 may be a conserved function of Mcm10 [7].
• A conserved Hsp10-like domain in Mcm10 is required to stabilize the catalytic subunit of DNA polymerase-alpha in budding yeast [7].

Analytical, diagnostic and therapeutic context of MCM10

• Two-dimensional gel electrophoresis analysis showed that Mcm10p is required not only for the initiation of DNA synthesis at replication origins but also for the smooth passage of replication forks at origins [3].

References