Binding, sliding, and function of cohesin during transcriptional activation.
The ring-shaped cohesin complex orchestrates long-range DNA interactions to mediate sister chromatid cohesion and other aspects of chromosome structure and function. In the yeast Saccharomyces cerevisiae, the complex binds discrete sites along chromosomes, including positions within and around genes. Transcriptional activity redistributes the complex to the 3' ends of convergently oriented gene pairs. Despite the wealth of information about where cohesin binds, little is known about cohesion at individual chromosomal binding sites and how transcription affects cohesion when cohesin complexes redistribute. In this study, we generated extrachromosomal DNA circles to study cohesion in response to transcriptional induction of a model gene, URA3. Functional cohesin complexes loaded onto the locus via a poly(dA:dT) tract in the gene promoter and mediated cohesion before induction. Upon transcription, the fate of these complexes depended on whether the DNA was circular or not. When gene activation occurred before DNA circularization, cohesion was lost. When activation occurred after DNA circularization, cohesion persisted. The presence of a convergently oriented gene also prevented transcription-driven loss of functional cohesin complexes, at least in M phase-arrested cells. The results are consistent with cohesin binding chromatin in a topological embrace and with transcription mobilizing functional complexes by sliding them along DNA.
['Borrie|Melinda S|MS|', 'Campor|John S|JS|', 'Joshi|Hansa|H|', 'Gartenberg|Marc R|MR|0000-0003-0713-7993']
D000251:Adenosine Triphosphatases D001665:Binding Sites D018797:Cell Cycle Proteins D002868:Chromosomal Proteins, Non-Histone D015825:Chromosomes, Fungal D004270:DNA, Circular D004271:DNA, Fungal D004268:DNA-Binding Proteins D005111:Extrachromosomal Inheritance D015966:Gene Expression Regulation, Fungal D005800:Genes, Fungal D017930:Genes, Reporter D005813:Genes, Synthetic D008677:Metaphase D046912:Multiprotein Complexes D011067:Poly dA-dT D011401:Promoter Regions, Genetic D011485:Protein Binding D012045:Regulatory Sequences, Nucleic Acid D012441:Saccharomyces cerevisiae D029701:Saccharomyces cerevisiae Proteins D015533:Transcriptional Activation
cohesin transcription sister chromatid cohesion URA3 poly(dA:dT)