Heat-shock proteins: chaperoning DNA repair

Cells are repeatedly exposed to environmental or endogenous stresses that can alter normal cell behavior and increase cell vulnerability. In order to ensure tissue integrity and function, cells cope with cellular injuries by adapting their metabolism, protecting essential intracellular constituents, inhibiting cell death signaling pathways and activating those devoted to damage repair. The molecular chaperones of the heat-shock protein (HSP) family are critical effectors of this adaptive response. They protect intracellular proteins from misfolding or aggregation, inhibit cell death signaling cascades and preserve the intracellular signaling pathways that are essential for cell survival. Most HSPs are rapidly overexpressed in response to cellular injuries including genotoxic stress. DNA damage can dramatically alter cell behavior and contribute to a number of diseases including developmental defects, neurodegenerative disorders, and cancer. Thus, the ability of cells to repair DNA damage is essential for preserving cell integrity. DNA damage activates a coordinated response that includes detecting DNA lesions before their transmission to daughter cells, blocking cell cycle progression and DNA replication and repairing the damage. Although the role of HSPs in proteins homeostasis and cell death, especially apoptosis has been widely reported, much less is known about their function in DNA repair. This review aims to present the role of HSPs in DNA repair signaling pathways.