As a Nucleus Enters a Small Pore, Chromatin Stretches and Maintains Integrity, Even with DNA Breaks.

ABSTRACT: As a cell pushes or pulls its nucleus through a small constriction, the chromatin must distort and somehow maintain genomic stability despite ever-present double-strand breaks in the DNA. Here we visualize within a living cell the pore-size dependent deformation of a specific locus engineered into chromosome-1 and cleaved. An mCherry-tagged nuclease targets the submicron locus, causing DNA cleavage and recruiting repair factors such as GFP-53BP1 to a large region around the locus. Aspiration of a cell and its nucleus into a micropipette shows that chromatin aligns and stretches parallel to the pore. Extension is largest in small pores, increasing >10-fold but remaining 30-fold shorter than the DNA contour length in the locus. Brochard and de Gennes' blob model for tube geometry fits the da

SUBMITTER: Irianto J 

PROVIDER: S-EPMC5300774 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature