Genomic integrity is critical for normal development, healthy aging and suppressing oncogenic transformation. The DNA damage response (DDR) is a complex network that is activated by DNA structural changes to preserve genome integrity. Situated at the apex of the mammalian DDR are three PI3-kinase-related protein kinases—ATM, DNA-PKcs and ATR. They are activated by different DNA lesions via direct binding to their unique sensor protein complexes (MRE11-RAD50-NBS1 for ATM, Ku70-Ku80/86 for DNA-PKcs and ATRIP-RPA for ATR) and phosphorylate a large number of partially overlapping substrates, including themselves and each other to promote DNA repair and regulate cell cycle checkpoints and tissue homeostasis. This review focuses on mouse models with deletion and point mutations of ATM, DNA-PKcs and ATR, and discusses how their activation mechanism and their kinase activity contribute to their unique, yet interactive roles in DNA repair in general and during tissue-specific development processes and how their deficiency leads to specific physiological and pathophysiological consequences.
The ubiquitin system plays a central role in diverse cellular processes including DNA damage response. As such, it is not surprising that its dysfunction contributes to various diseases including cancer and neurodegenerative disorders. An understanding of the ubiquitin system is, therefore, important in devising treatments for such diseases. In this review, we discuss the central role of ubiquitin in DNA damage response, specifically DNA double-strand break repair. We focus on recent findings on the role of ubiquitin in the DNA double-strand break repair pathway, possible nodes of modulation, and finally their implications for treatment of various diseases.
Living organisms have developed a complex signaling system to sense diverse growth signals and co-ordinate intracellular bioprocesses, so that they survive in various conditions. Since organisms are often exposed to environmental and genomic threats which cause DNA damages, DNA damage response (DDR) and repair systems are important for maintenance of genome stability and integrity. A line of evidences has demonstrated that there is tight crosstalk between growth signaling pathways and DDR systems. In this review, we give a brief overview of recent reports dissecting the interaction between signaling pathways and DDR at molecular level, which may further expand the knowledge of the signaling network and provide clues for disease therapy.
Pluripotent stem cells (PSCs) are capable of generating all types of cells in the body and have promising applications in basic research and cell-based regenerative medicine. Compared to the differentiated cells, PSCs are superior in maintaining genomic stability. However, the underlying molecular mechanisms are far from clear. Here, we summarized the understandings on the molecules and pathways that PSCs specifically utilize to cope with DNA replication-associated stress, to repair DNA damages and to determine cell fates.