Interactions of MCP1 with Components of the Replication Machinery in Mammalian Cells

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Elsa Bronze da Rocha (Author) FFUP; Chii Mei Lin (Author) Other; Tsutomu Shimura (Author) Other; Mirit I Aladjem (Author) Other

Journal

Title: International Journal of Biological Sciences

Vol. 7

Pages: 193-208

ISSN: 1449-2288

Publisher: Ivyspring International Publisher

Indexing

ISI Web of Knowledge - 1 Citation

Scopus - 1 Citation

Scientific classification

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-002-YSJ

Abstract (EN): Eukaryotic DNA replication starts with the assembly of a pre-replication complex (pre-RC) at replication origins. We have previously demonstrated that Metaphase Chromosome Protein 1 (MCP1) is involved in the early events of DNA replication. Here we show that MCP1 associates with proteins that are required for the establishment of the pre-replication complex. Reciprocal immunoprecipitation analysis showed that MCP1 interacted with Cdc6, ORC2, ORC4, MCM2, MCM3 and MCM7, with Cdc45 and PCNA. Immunofluorescence studies demonstrated the co-localization of MCP1 with some of those proteins. Moreover, biochemical studies utilizing chromatin-immunoprecipitation (ChIP) revealed that MCP1 preferentially binds replication initiation sites in human cells. Interestingly, although members of the pre-RC are known to interact with some hallmarks of heterochromatin, our co-immunoprecipitation and immunofluorescence analyses showed that MCP1 did not interact and did not co-localize with heterochromatic proteins including HP1 beta and MetH3K9. These observations suggest that MCP1 is associated with replication factors required for the initiation of DNA replication and binds to the initiation sites in loci that replicate early in S-phase. In addition, immunological assays revealed the association of MCP1 forms with histone H1 variants and mass spectrometry analysis confirmed that MCP1 peptides share common sequences with H1.2 and H1.5 subtypes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 16