MgLig4, a homolog of Neurospora crassa Mus-53 (DNA ligase IV), is involved in, but not essential for, non-homologous end-joining events in Magnaporthe grisea.
In many eukaryotic organisms, the non-homologous end-joining (NHEJ) system is a major pathway for the repair of DNA double-strand breaks (DSBs). DNA ligase IV is a component of the NHEJ system and is strictly required for the NHEJ system in Saccharomyces cerevisiae and in Neurospora crassa. To investigate the functions of DNA Ligase IV in Magnaporthe grisea, we generated deletion mutants of MGLIG4, which encodes a homolog of N. crassa DNA Ligase IV. Mutants (mglig4) showed no defects in asexual or sexual growth, and were fully pathogenic. Compared to the wild-type, mglig4 exhibited weak sensitivity to a DNA-damaging agent, camptothecin. In addition, the frequency of targeted-gene replacement was relatively elevated in mglig4, although this varied in a gene-dependent manner. Surprisingly, non-homologous integration of DNA was frequently observed in mglig4 transformants. Our results demonstrate that MgLig4 is involved in, but not essential for, the NHEJ system in M. grisea.
National Institute of Agrobiological Sciences, 2-1-2, Kan'non dai, Tsukuba, Ibaraki 305-8602, Japan.
Hideki
H
Kito
Takashi
T
Fujikawa
Akihiro
A
Moriwaki
Ayami
A
Tomono
Masumi
M
Izawa
Takashi
T
Kamakura
Miho
M
Ohashi
Hiroyoshi
H
Sato
Keietsu
K
Abe
Marie
M
Nishimura
D000935:Antifungal Agents / Q000494:pharmacology; D002166:Camptothecin / Q000494:pharmacology; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004271:DNA, Fungal / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D020082:Magnaporthe / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D010802:Phylogeny; D011995:Recombination, Genetic; D017385:Sequence Homology
D000935:Antifungal Agents; D004271:DNA, Fungal; C000607891:DNL4 protein, S cerevisiae; D005656:Fungal Proteins; D011088:DNA Ligases; D000072481:DNA Ligase ATP; D002166:Camptothecin