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Phosphorylation of MCM4 at Sites Inactivating DNA Helicase Activity of the MCM4-MCM6-MCM7 Complex during Epstein-Barr Virus Productive Replication
- Source :
- Journal of Virology. 80:10064-10072
- Publication Year :
- 2006
- Publisher :
- American Society for Microbiology, 2006.
-
Abstract
- Induction of Epstein-Barr virus (EBV) lytic replication blocks chromosomal DNA replication notwithstanding an S-phase-like cellular environment with high cyclin-dependent kinase (CDK) activity. We report here that the phosphorylated form of MCM4, a subunit of the MCM complex essential for chromosomal DNA replication, increases with progression of lytic replication, Thr-19 and Thr-110 being CDK2/CDK1 targets whose phosphorylation inactivates MCM4-MCM6-MCM7 (MCM4-6-7) complex-associated DNA helicase. Expression of EBV-encoded protein kinase (EBV-PK) in HeLa cells caused phosphorylation of these sites on MCM4, leading to cell growth arrest. In vitro, the sites of MCM4 of the MCM4-6-7 hexamer were confirmed to be phosphorylated with EBV-PK, with the same loss of helicase activity as with CDK2/cyclin A. Introducing mutations in the N-terminal six Ser and Thr residues of MCM4 reduced the inhibition by CDK2/cyclin A, while EBV-PK inhibited the helicase activities of both wild-type and mutant MCM4-6-7 hexamers, probably since EBV-PK can phosphorylate MCM6 and another site(s) of MCM4 in addition to the N-terminal residues. Therefore, phosphorylation of the MCM complex by redundant actions of CDK and EBV-PK during lytic replication might provide one mechanism to block chromosomal DNA replication in the infected cells through inactivation of DNA unwinding by the MCM4-6-7 complex.
- Subjects :
- Threonine
Herpesvirus 4, Human
Immunology
Mutation, Missense
Cell Cycle Proteins
Eukaryotic DNA replication
Cyclin A
Virus Replication
Pre-replication complex
Microbiology
DNA replication factor CDT1
Viral Proteins
Replication factor C
Control of chromosome duplication
Minichromosome maintenance
Virology
Humans
Phosphorylation
S phase
biology
Cyclin-Dependent Kinase 2
DNA Helicases
Nuclear Proteins
DNA
Molecular biology
Genome Replication and Regulation of Viral Gene Expression
Minichromosome Maintenance Complex Component 4
DNA-Binding Proteins
Amino Acid Substitution
Insect Science
Mutagenesis, Site-Directed
biology.protein
Origin recognition complex
Protein Kinases
Protein Processing, Post-Translational
Cell Division
HeLa Cells
Subjects
Details
- ISSN :
- 10985514 and 0022538X
- Volume :
- 80
- Database :
- OpenAIRE
- Journal :
- Journal of Virology
- Accession number :
- edsair.doi.dedup.....0eddcb3719417509d67eecce511e0559