Condensin II Counteracts Cohesin and RNA Polymerase II in the Establishment of 3D Chromatin Organization

• Authors: M. Jordan Rowley, Emory University; Xiaowen Lyu, Emory University; Vibhuti Rana, Geisel School of Medicine at Dartmouth; Masami Ando-Kuri, Emory University; Rachael Karns, Emory University; Giovanni Bosco, Geisel School of Medicine at Dartmouth; Victor Corces, Emory University
• Journal Title: Cell Reports
• Volume: Volume 26, Number 11
• Publisher: Elsevier (Cell Press): OAJ | 2019-03-12, Pages 2890-+
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.celrep.2019.01.116
• Subjects: Biology, Cell; Biology, Molecular
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cell Biology; MAMMALIAN GENOMES; DROSOPHILA; ARCHITECTURE; CTCF; CHROMOSOME; PRINCIPLES; PROMOTERS; DOMAINS; TRANSCRIPTION; TRANSVECTION

Abstract

Interaction domains in Drosophila chromosomes form by segregation of active and inactive chromatin in the absence of CTCF loops, but the role of transcription versus other architectural proteins in chromatin organization is unclear. Here, we find that positioning of RNAPII via transcription elongation is essential in the formation of gene loops, which in turn interact to form compartmental domains. Inhibition of transcription elongation or depletion of cohesin decreases gene looping and formation of active compartmental domains. In contrast, depletion of condensin II, which also localizes to active chromatin, causes increased gene looping, formation of compartmental domains, and stronger intra-chromosomal compartmental interactions. Condensin II has a similar role in maintaining inter-chromosomal interactions responsible for pairing between homologous chromosomes, whereas inhibition of transcription elongation or cohesin depletion has little effect on homolog pairing. The results suggest distinct roles for cohesin and condensin II in the establishment of 3D nuclear organization in Drosophila.