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Disengaging the Smc3/kleisin interface releases cohesin from Drosophila chromosomes during interphase and mitosis
Author(s) -
Eichinger Christian S,
Kurze Alexander,
Oliveira Raquel A,
Nasmyth Kim
Publication year - 2013
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2012.346
Subject(s) - cohesin , biology , separase , mitosis , chromosome segregation , microbiology and biotechnology , establishment of sister chromatid cohesion , interphase , anaphase , chromatin , premature chromosome condensation , prophase , dna , cell cycle , biochemistry , chromosome , cell , meiosis , gene
Cohesin's Smc1, Smc3, and kleisin subunits create a tripartite ring within which sister DNAs are entrapped. Evidence suggests that DNA enters through a gate created by transient dissociation of the Smc1/3 interface. Release at the onset of anaphase is triggered by proteolytic cleavage of kleisin. Less well understood is the mechanism of release at other stages of the cell cycle, in particular during prophase when most cohesin dissociates from chromosome arms in a process dependent on the regulatory subunit Wapl. We show here that Wapl‐dependent release from salivary gland polytene chromosomes during interphase and from neuroblast chromosome arms during prophase is blocked by translational fusion of Smc3's C‐terminus to kleisin's N‐terminus. Our findings imply that proteolysis‐independent release of cohesin from chromatin is mediated by Wapl‐dependent escape of DNAs through a gate created by transient dissociation of the Smc3/kleisin interface. Thus, cohesin's DNA entry and exit gates are distinct.