Table 2.

Mitochondrial oxidative stress associated with deficiencies in DNA helicases.

Helicase	Oxidative Stress Phenotype
XPD	XPD-deficient cells display increased ROS production in mitochondria and are hypersensitive to H2O2- induced oxidative DNA damage169.
RECQL4	RECQL4-deficient cells have increased endogenous DNA damage, increased mitochondrial superoxide production, lower reserve capacity, and elevated aerobic glycolysis-dependent cell invasion171, 173, 176.
DNA2	DNA2-deficient cells are compromised in their ability to repair mitochondrial oxidative DNA lesions by the BER pathway179, 180.
PIF1	To our knowledge, the status of PIF1 deficiency on oxidative DNA damage processing in human cell has not been determined.
SUV3	No direct role of SUV3 deficiency on oxidative DNA damage processing in human cells has been determined; however, SUV3 belongs to a protein complex that modulates messenger RNA polyadenylation in response to cellular energy changes198.
Twinkle	Overexpressed Twinkle in a transgenic mouse model suppresses symptoms induced by oxidative stress205,206.
CSB*	CSB-deficient cells display reduced mitochondrial BER212, 219, 220 , altered redox balance and elevated ROS213, 214, 215 . CSB-deficient mice and human cells display reduced mitophagy214 . PARP1 is hyper- activated in CSB-deficient mice216.

^*CSB contains the conserved ATPase/helicase motifs and is an ATP-dependent DNA translocase, but not a bona fide helicase.