The accumulation of defective products in the mitochondria generates mitochondrial instability and information loss on its genome, according to a study developed at the Andalusian Centre for Molecular Biology and Regenerative Medicine (CABIMER). These finding may help understanding the molecular basis of some diseases linked to poor mitochondrial function, and thus it may open the door to the development of new therapies against such diseases.
The loss of information in the mitochondrial genome results in defective cell metabolism, incapacity to generate the necessary energy for the cell, and can generate an increase in oxygen free radicals that attack and damage the genetic material or produce Iron-Sulphur protein deficiencies. All these factors results in incorrect cell functioning and finally cell death.
The study, published in Proceedings of the National Academy of Sciences, showed that Degradosome, a multiprotein complex which involved in degrading defective RNA that is produced in the mitochondria, is essential for maintaining mitochondrial genome integrity. When degradosome is inactive RNA accumulates in the mitochondria generating abnormal structures. These structures are called DNA-RNA hybrids, which are harmful when accumulated in excess, impeding mitochondrial replication. So, when cells divide, they lose mitochondrial DNA compromising mitoSchondrial function in the cell.
Source: Science Daily