FAKD3 is a member of a small family of Fas-activated serine/threonine kinase domain (FASTKD) containing proteins that share an amino terminal mitochondrial targeting domain and multiple carboxy terminal FAST domains as well as a putative RNA-binding RAP domain. The members of this family are ubiquitously expressed and are generally most abundant in mitochondria-enriched tissues such as heart, skeletal muscle and brown-adipose tissue. Some members of this protein family may play a role in apoptosis. The protein encoded by this gene interacts with components of the mitochondrial respiratory and translation networks. A pseudogene of this gene is also present on chromosome 5. Alternative splicing results in multiple transcript variants.