Karine Gouget et al. (2002) Worm Breeder's Gazette "C.elegans as a model to study human diseases linked to the mitochondrial respiratory chain complex II"

You-Fang Zhou, Mose Pinto, Karine Gouget, Monique Bolotin-Fukuhara, Emmanuel Culetto

[Worm Breeder's Gazette, 2002]

The mitochondria play a critical role in the cellular energy supply and perform other essential roles in a variety of metabolic functions. The mitochondria electron transport respiratory chain (MRC) is typically composed of four multi-subunit enzymes (complexes I to IV) and the ATP synthase (complex V). Complex II is involved in both the tricarboxylic acid (TCA) cycle and the aerobic respiratory chains of mitochondria. It consists of 4 nuclear-encoded polypeptides: the flavoprotein (Fp/ SDHA), an iron-sulphur protein (Ip/ SDHB) and two integral membrane proteins (SDHC and SDHD). Clinically, complex II deficiency associated with SDHA gene mutations can result in myopathy, encephalopathy and isolated cardiomyopathy. Recently, the analysis of the susceptibility gene for familial paraganglioma syndrome revealed germ line mutations in the SDHB, SDHC and SDHD genes. Those genes are therefore considered to be tumor-suppressor genes. One can speculate that oxidative damage or ROS recycling dysfunction from impaired complex II could be important in explaining the damage to muscle and nerve cells. The molecular basis of such MRC enzyme deficiencies in humans remains largely unknown (1).