Muscle-specific RING finger (MuRF) proteins are E3-ubiquitin ligases and key regulators of muscle growth and turnover. Here, using a range of phylogenomic approaches, we established the complete-definitive MuRF family of vertebrates. Adding to recognized MuRF1, 2 and 3, we describe a novel family member, hereafter MuRF4, which was independently lost during placental mammal and bird evolution, but is otherwise conserved. MuRF4 transcripts were expressed in heart and skeletal muscles of zebrafish, but were barely detectable in striated muscles of adult anole lizards. We also demonstrate that MuRF1 underwent retrotransposition in the teleost fish ancestor, before the retrogene fully replaced the original gene and muscle-specific function.
Bibliographical noteThis work was supported by a visiting fellowship funded by the Marine Alliance for Science and Technology for Scotland (Grant No. VF20) and by start-up funds to D.J.M. from the University of Aberdeen. E.N.F. also receives support from a FONDAP project (Grant No. 15110027) granted by CONICYT-Chile. Samples used for transcript expression studies were a gift from Professor Ian A. Johnston (University of St Andrews, UK).
- muscle-specific RING finger family
- Novel MuRF: MuRF4
- striated muscle
- E3-ubiquitin ligase