Sister chromatid cohesion halts DNA loop expansion

Abstract

AbstractEukaryotic genomes are folded into DNA loops mediated by structural maintenance of chromosomes (SMC) complexes such as cohesin, condensin and Smc5/6. This organization regulates different DNA-related processes along the cell cycle such as transcription, recombination, segregation and DNA repair. During G2/M stages, SMC-mediated DNA loops coexist with cohesin complexes involved in sister chromatid cohesion (SCC). However, the articulation between the establishment of SCC and the formation of SMC-mediated DNA loops along the chromatin remains unknown. Here we show that SCC is indeed a barrier to cohesin-mediated DNA loop expansion in G2.