Figure 3.

Ku80 present in intact mitochondria is resistant to proteinase K, while that present in the nucleus is not. (A) Western blot analysis of intact nuclei and intact percoll-purified mitochondria incubated in the absence (–) or presence (+) of 20 µg/µl proteinase K. The positions of marker proteins and their molecular weights are indicated (in kDa). (B) Western blot analysis of intact crude mitochondria (lanes 1 and 2) and lysed crude mitochondria (lanes 3 and 4) pre-incubated in the absence (–) or presence (+) of 20 µg/µl proteinase K.