MCM8 is an MCM2-7-related protein that functions as a DNA helicase during replication elongation and not initiation

Domenico Maiorano; Olivier Cuvier; Etienne Danis; Marcel Méchali

doi:10.1016/j.cell.2004.12.010

MCM8 is an MCM2-7-related protein that functions as a DNA helicase during replication elongation and not initiation

Cell. 2005 Feb 11;120(3):315-28. doi: 10.1016/j.cell.2004.12.010.

Authors

Domenico Maiorano¹, Olivier Cuvier, Etienne Danis, Marcel Méchali

Affiliation

¹ Institute of Human Genetics, Centre National de la Recherche Scientifique, 141 rue de la Cardonille, 34396 Montpellier Cedex 05, France.

PMID: 15707891
DOI: 10.1016/j.cell.2004.12.010

Abstract

MCM2-7 proteins are replication factors required to initiate DNA synthesis and are currently the best candidates for replicative helicases. We show that the MCM2-7-related protein MCM8 is required to efficiently replicate chromosomal DNA in Xenopus egg extracts. MCM8 does not associate with the soluble MCM2-7 complex and binds chromatin upon initiation of DNA synthesis. MCM8 depletion does not affect replication licensing or MCM3 loading but slows down DNA synthesis and reduces chromatin recruitment of RPA34 and DNA polymerase-alpha. Recombinant MCM8 displays both DNA helicase and ATPase activities in vitro. Reconstitution experiments show that ATP binding in MCM8 is required to rescue DNA synthesis in MCM8-depleted extracts. MCM8 colocalizes with replication foci and RPA34 on chromatin. We suggest that MCM8 functions in the elongation step of DNA replication as a helicase that facilitates the recruitment of RPA34 and stimulates the processivity of DNA polymerases at replication foci.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphatases / metabolism
Animals
Cell Cycle Proteins / genetics
Cell Cycle Proteins / isolation & purification
Cell Cycle Proteins / metabolism*
Chromosomes / physiology*
DNA / biosynthesis
DNA Helicases / genetics
DNA Helicases / isolation & purification
DNA Helicases / metabolism*
DNA Polymerase I / metabolism
DNA Replication / physiology*
DNA-Binding Proteins / metabolism
Down-Regulation / physiology
Female
Minichromosome Maintenance Complex Component 2
Minichromosome Maintenance Proteins
Mitosis / genetics*
Molecular Sequence Data
Nuclear Proteins / genetics
Nuclear Proteins / metabolism
Oocytes
Rabbits
Xenopus
Xenopus Proteins / genetics
Xenopus Proteins / isolation & purification
Xenopus Proteins / metabolism*

Substances

Cell Cycle Proteins
DNA-Binding Proteins
Nuclear Proteins
RPAp34 protein, rat
Xenopus Proteins
DNA
DNA Polymerase I
Adenosine Triphosphatases
DNA Helicases
MCM2 protein, human
MCM8 protein, Xenopus
MCM8 protein, human
Minichromosome Maintenance Complex Component 2
Minichromosome Maintenance Proteins

Associated data

GENBANK/AJ867218