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

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 and live cell images of human cells expressing fluorescently tagged Orc1 show that Orc1 re-localizes to condensing chromatin during early mitosis and then displays different nuclear localization patterns at different times during G1 phase, remaining asso

SUBMITTER: Kara N 

PROVIDER: S-EPMC4424365 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature