Abstract
Ataxia telangiectasia-like disorder (ATLD) is the genetic disorder, which is characterized by high sensitivity to radiation, chromosome instability and aberrant cell cycle checkpoint. MRE11,the gene responsible for Ataxia telangiectasia-like disorder ,forms a protein complex with hNBS1 and hRAD50 , and functions in homologous recombination (HR) repair from DNA double strand breaks, which are elicited by ionizing radiation or other stresses. Therefore, the chromosome instability in MRE11 cells is considered to be due to defects in both DNA repair and cell cycle checkpoints.
Now, we find MRE11 co-localize with centrosome and involved in centrosome regulation. Centrosome is the complex organelles comprising two microtuble-based centrioles surrounded by a protein matrix and other structural elements, a key regulator for chromosome separation in mitosis. Centrosome duplication and spindle formation are crucial for prevention of chromosomal instability. Therefore, the normal function of centrosome is essential for maintenance of genome stability. Recent studies suggest that BRCA1 is HR repair protein ,localizes to the centrosome in mitosis. Therefore , BRCA1-defective cells showed the abnormal duplication of centrosome .
When we examined the localization of MRE11 by using a protein antibody, they showed to be accumulated in centrosomes. Moreover, MRE11 cells showed defect in centrosome amplification, suggesting an indispensable role of MRE11 in centrosome maintenance. We further discuss this novel role of MRE11 in centrosome maintenance.
