Heterochromatin and the cohesion of sister chromatids.
Heterochromatin, once thought to be the useless junk of chromosomes, is now known to play significant roles in biology. Underlying much of this newfound fame are links between the repressive chromatin structure and cohesin, the protein complex that mediates sister chromatid cohesion. Heterochromatin-mediated recruitment and retention of cohesin to domains flanking centromeres promotes proper attachment of chromosomes to the mitotic and meiotic spindles. Heterochromatin assembled periodically between convergently transcribed genes also recruits cohesin, which promotes a novel form of transcription termination. Heterochromatin-like structures in budding yeast also recruit cohesin. Here the complex appears to regulate transcriptional silencing and recombination between repeated DNA sequences. The link between heterochromatin and cohesin is particularly relevant to human health. In Roberts-SC phocomelia syndrome, heterochromatic cohesion is selectively lost due to mutation of the acetyltransferase responsible for cohesin activation. In this review I discuss recent work that relates to these relationships between heterochromatin and cohesin.
Gartenberg
Marc
M
Department of Pharmacology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA. gartenbe@umdnj.edu
D000123:Acetyltransferases / Q000172:deficiency / Q000235:genetics; D000818:Animals; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000502:physiology*; D002503:Centromere / Q000502:physiology; D002842:Chromatids / Q000502:physiology* / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000502:physiology; D004275:DNA, Ribosomal / Q000235:genetics; D004480:Ectromelia / Q000235:genetics; D020868:Gene Silencing; D006570:Heterochromatin / Q000502:physiology* / Q000648:ultrastructure; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D008957:Models, Genetic; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000502:physiology; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology; D008941:Spindle Apparatus / Q000502:physiology; D000097722:Cohesins
D000123:Acetyltransferases; D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004275:DNA, Ribosomal; D006570:Heterochromatin; D006657:Histones; D017346:Protein Serine-Threonine Kinases; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D000097722:Cohesins; C500785:ESCO2 protein, human