Orc1 Binding to Mitotic Chromosomes Precedes Spatial Patterning During G1 Phase and Assembly of the Origin Recognition Complex in Human Cells

Kara, N., Hossain, M., Prasanth, S. G., Stillman, B. (2015) Orc1 Binding to Mitotic Chromosomes Precedes Spatial Patterning During G1 Phase and Assembly of the Origin Recognition Complex in Human Cells. J Biol Chem, 290 (19). pp. 12355-12369. ISSN 0021-9258

URL: http://www.ncbi.nlm.nih.gov/pubmed/25784553
DOI: 10.1074/jbc.M114.625012

Abstract

Replication of eukaryotic chromosomes occurs once every cell division cycle in normal cells and is a tightly controlled process that ensures complete genome duplication. The Origin Recognition Complex (ORC) plays a key role during the initiation of DNA replication. In human cells, the level of Orc1, the largest subunit of ORC, is regulated during the cell division cycle and thus ORC is a dynamic complex. Upon S phase entry, Orc1 is ubiquitinated and targeted for destruction, with subsequent dissociation of ORC from chromosomes. Time lapse, live cell images of human cells expressing fluorescently tagged-Orc1 shows that Orc1 re-localizes to condensing chromatin during early mitosis and then displays different nuclear localization patterns at different times during G1 phase, remaining associated with late replicating regions of the genome in late G1 phase. The initial binding of Orc1 to mitotic chromosomes requires C-terminal amino-acid sequences that are similar to mitotic chromosome binding sequences in the transcriptional pioneer protein FOXA1. Depletion of Orc1 causes concomitant loss of the mini-chromosome maintenance (Mcm2-7) helicase proteins on chromatin. The data suggest that Orc1 acts as a nucleating center for ORC assembly and then pre-RC assembly by binding to mitotic chromosomes, followed by gradual removal from chromatin during G1 phase.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > DNA replication
organs, tissues, organelles, cell types and functions > cell types and functions > cell functions > cell cycle
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > DNA binding protein
organs, tissues, organelles, cell types and functions > organelles, types and functions > mitosis
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > origin recognition complex
CSHL Authors:
Communities: CSHL labs > Stillman lab
CSHL Cancer Center Program > Gene Regulation and Cell Proliferation
Highlight: Stillman, Bruce W.
Depositing User: Matt Covey
Date Deposited: 19 Mar 2015 18:14
Last Modified: 20 Jun 2017 15:54
PMCID: PMC4424365
Related URLs:
URI: http://repository.cshl.edu/id/eprint/31288

Actions (login required)

Administrator's edit/view item Administrator's edit/view item
CSHL HomeAbout CSHLResearchEducationNews & FeaturesCampus & Public EventsCareersGiving