Mre11 and Blm-Dependent Formation of ALT-Like Telomeres in Ku-Deficient Ustilago maydis
Fig 9
Model for the ALT-like pathway in the U. maydis ku mutants.
The ALT-like pathway is normally restrained by the Ku70/Ku80 heterodimers at telomeres. When the Ku complex is lost from chromosome ends, the activities of multiple DNA processing factors (especially those of Blm and the MRN complex) become mis-regulated, resulting in aberrant resection and recombination, which in turn produce ALT-like telomeres. Subsequently, the activation of the checkpoint pathway alters the activities of the processing factors and perhaps recruits other proteins to telomeres, leading eventually to the terminal telomere phenotypes.