Letter abstract
Nature Cell Biology 7, 412 - 419 (2005)
Published online: 27 March 2005 | doi:10.1038/ncb1239
SMC5 and SMC6 genes are required for the segregation of repetitive chromosome regions
Jordi Torres-Rosell1, Félix Machín1, Sarah Farmer1, Adam Jarmuz1, Trevor Eydmann2, Jacob Z. Dalgaard2 & Luis Aragón1
Structure chromosome (SMC) proteins organize the core of cohesin, condensin and Smc5–Smc6 complexes1. The Smc5–Smc6 complex is required for DNA repair, as well as having another essential but enigmatic function1. Here, we generated conditional mutants of SMC5 and SMC6 in budding yeast, in which the essential function was affected. We show that mutant smc5-6 and smc6-9 cells undergo an aberrant mitosis in which chromosome segregation of repetitive regions is impaired; this leads to DNA damage and RAD9-dependent activation of the Rad53 protein kinase. Consistent with a requirement for the segregation of repetitive regions, Smc5 and Smc6 proteins are enriched at ribosomal DNA (rDNA) and at some telomeres. We show that, following Smc5–Smc6 inactivation, metaphase-arrested cells show increased levels of X-shaped DNA (Holliday junctions) at the rDNA locus. Furthermore, deletion of RAD52 partially suppresses the temperature sensitivity of smc5-6 and smc6-9 mutants. We also present evidence showing that the rDNA segregation defects of smc5/smc6 mutants are mechanistically different from those previously observed for condensin mutants2, 3. These results point towards a role for the Smc5–Smc6 complex in preventing the formation of sister chromatid junctions, thereby ensuring the correct partitioning of chromosomes during anaphase.
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College London, Du Cane Road, London W12 0NN, UK.
- Marie Curie Research Institute, The Chart, Oxted, Surrey RH8 0TL, UK.
Correspondence to: Luis Aragón1 e-mail: luis.aragon@csc.mrc.ac.uk
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Cdc14 phosphatase resolves the rDNA segregation delayNature Cell Biology News and Views (01 Jun 2004)
The importance of being Smc5/6Nature Cell Biology News and Views (01 Apr 2005)
See all 7 matches for News And ViewsRESEARCH
The conserved kinetochore protein shugoshin protects centromeric cohesion during meiosisNature Article (05 Feb 2004)
Lte1, Cdc14 and MEN-controlled Cdk inactivation in yeast coordinate rDNA decompaction with late telophase progressionThe EMBO Journal Article (03 Jun 2009)
See all 65 matches for Research
