Accurate repair of non-cohesive, double strand breaks in Saccharomyces cerevisiae: enhancement by homology-assisted end-joining.
Although the joining of blunt ends in yeast by non-homologous end joining (NHEJ) is reported to be inefficient in comparison to cohesive-end joining (Boulton and Jackson, 1996), we find that efficiency varies greatly, depending on strain, growth phase and sequence. In particular, the levels of efficiency of recircularization of a plasmid linearized by non-cohesive cleavage is augmented to that of cohesive end joining if the cleavage cut site is flanked by sequences present in the genome. We call this enhancement 'homology-assisted end joining' (HAEJ), which depends on components of the NHEJ repair pathway and, in some cases, on components of the homologous recombination (HR) pathway and on Htl1 a component of the remodels structure of chromatin (RSC) complex. The homologous genome sequences are not used as templates for repair DNA synthesis, but may facilitate end-to-end collision and ligation by providing a track for guided diffusion.
Moscariello
Mario
M
Università degli Studi di Napoli Federico II, Dipartimento di Biologia Strutturale e Funzionale, Naples, Italy.
Florio
Carolina
C
Pulitzer
John F
JF
D018797:Cell Cycle Proteins; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004261:DNA Replication; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D018797:Cell Cycle Proteins; C469779:HTL1 protein, S cerevisiae; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins