Nijmegen breakage syndrome disease protein and MRE11 at PML nuclear bodies and meiotic telomeres.

Nijmegen breakage syndrome is a disease characterized by immunodeficiency, genomic instability, and cancer susceptibility. The gene product defective in Nijmegen breakage syndrome, p95, associates with two other proteins, MRE11 and RAD50. Here we demonstrate that in the absence of DNA damage, a portion of p95 and MRE11 is concentrated in PML nuclear bodies (NBs); MRE11 localization to the NBs is p95-dependent. In mammalian meiocytes, these proteins are specifically found at the telomeres. These results implicate the NBs in the maintenance of genomic stability and suggest that p95 and MRE11 may have roles in telomere maintenance in mammals, analogous to the role their homologues play in yeast.