DNA damage response is a complex signal transduction process that includes sensing DNA damage, transducing the information to the cell and directing the cell to make an appropriate decision in response to the damage. A failure at any of these steps leads to cancer and other human diseases. Building on the solid foundation laid out by decades of research, scientists in the field have made remarkable progress in recent years elucidating the mechanisms of DNA damage response and its roles in genome maintenance. The collection of review articles in this issue attempts to define the most challenging questions concerning DNA damage response and repair, and to provide an overview of the latest breakthroughs and developments in the field. A striking example is the recent discovery of the many functions of the structural maintenance of chromosomes (Smc) proteins in DNA damage response and repair. As illustrated on the cover, the Smc5/6 complex and cohesin function in the same pathway to promote sister-chromatid homologous recombination (i). The Smc5/6 complex also promotes homologous recombination-dependent rescue of stalled replication forks by stabilizing them in recombination-competent configurations and by facilitating the resolution or preventing the formation of undesirable recombination intermediates (ii). Finally, the Smc5/6 complex mediates the nucleolar exclusion of Rad52, thereby suppressing the recombinational loss of rDNA repeats to ensure rDNA stability (iii).
Dr Guo-Min Li