Identification of cohesin association sites at centromeres and along chromosome arms

A multisubunit cohesin complex holds sister chromatids together after DNA r eplication. Using chromatin immunoprecipitation, we detected cohesin associ ation with centromeres and with discrete sites along chromosome arms from S phase until metaphase in S. cerevisiae, Short DNA sequences (130-280 bp) a re sufficient to confer cohesin association. Cohesin association with a cen tromere depends on Mif2p, the centromere binding factor CBF3, and a centrom ere-specific histone variant, Cse4p. Because only active centromeres confer cohesin association with centromeric DNA, we suggest that cohesin is recru ited by the same chromatin structure that confers the attachment of microtu bules. Propagation of this structure might be partly epigenetic. Finally, c ohesion associated with "minimal" centromeres is insufficient to resist the splitting force exerted by microtubules and appears to be reinforced by co hesion provided by their flanking DNA sequences.