An Actn3 knockout mouse provides mechanistic insights into the association between alpha-actinin-3 deficiency and human athletic performance

作者：MacArthur Daniel G; Seto Jane T; Chan Stephen; Quinlan Kate G R; Raftery Joanna M; Turner Nigel; Nicholson Megan D; Kee Anthony J; Hardeman Edna C; Gunning Peter W; Cooney Gregory J; Head Stewart I; Yang Nan; North Kathryn N^*

来源：Human Molecular Genetics, 2008, 17(8): 1076-1086.

DOI：10.1093/hmg/ddm380

A common nonsense polymorphism (R577X) in the ACTN3 gene results in complete deficiency of the fast skeletal muscle fiber protein alpha-actinin-3 in an estimated one billion humans worldwide. The XX null genotype is under-represented in elite sprint athletes, associated with reduced muscle strength and sprint performance in non-athletes, and is over-represented in endurance athletes, suggesting that alpha-actinin-3 deficiency increases muscle endurance at the cost of power generation. Here we report that muscle from Actn3 knockout mice displays reduced force generation, consistent with results from human association studies. Detailed analysis of knockout mouse muscle reveals reduced fast fiber diameter, increased activity of multiple enzymes in the aerobic metabolic pathway, altered contractile properties, and enhanced recovery from fatigue, suggesting a shift in the properties of fast fibers towards those characteristic of slow fibers. These findings provide the first mechanistic explanation for the reported associations between R577X and human athletic performance and muscle function.

• 出版日期2008-4-15
• 单位河北医科大学